Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/12/12
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1242 AM EST TUE JAN 10 2012
.SYNOPSIS...
LOW PRESSURE PASSES WELL OFFSHORE TONIGHT. HIGH PRESSURE BUILDS IN
TUESDAY AND WEDNESDAY. LOW PRESSURE APPROACHES ON WEDNESDAY NIGHT
AND PASSES THROUGH ON THURSDAY. A BROAD AREA OF LOW PRESSURE
REMAINS ACROSS THE AREA THROUGH FRIDAY NIGHT. HIGH PRESSURE THEN
BUILDS IN DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MINOR ADJUSTMENTS TO TEMPS AND DEWPOINTS. LOWS TEMPERATURES HAVE
ALREADY BEEN REACHED IN THE RURAL OUTLYING SECTIONS WITH OTHER
LOCATIONS DROPPING AT LEAST ANOTHER SEVERAL DEGREES BY THE EARLY
MORNING HOURS. POPS TAPERED DOWN SLIGHTLY AND PUSHED FARTHER SOUTH
AND EAST BUT DID NOT WANT TO DROP THEM ALL TOGETHER GIVEN THE
POTENT SHORTWAVE STILL FORECAST TO MOVE JUST SOUTH OF THE AREA.
LEFT POPS AT SLIGHT CHANCE. LOCAL WRF AND HRRR ALSO SHOW SOME
FORECAST PRECIP WITHIN SOUTHEAST PORTIONS OF FORECAST
AREA...MAINLY SOUTH OF LONG ISLAND THOUGH. HOWEVER...IF THE TREND
CONTINUES WITH THE RADAR RETURNS...LOOKS LIKE MUCH OF THE FORECAST
REGION WILL REMAIN DRY TONIGHT WITH ANY PRECIPITATION STAYING
SOUTH OF LONG ISLAND AFFECTING SOUTHERN OUTER PORTIONS OF OCEAN
MARINE ZONES.
PRECIP TYPE AFTER ACCOUNTING FOR WET BULB PROFILES WILL ALLOW FOR
ANY PRECIPITATION TO BE MOSTLY LIGHT SNOW FOR CENTRAL LONG ISLAND
AND SOUTHEAST CONNECTICUT AND A MIX OF RAIN AND SNOW CLOSER TO THE
TWIN FORKS OF LONG ISLAND. THE TIME PERIOD OF THIS WOULD BE MAINLY
AFTER MIDNIGHT AND COULD BE BRIEF IN DURATION AS TOTAL QPF IS AT
BEST A FEW HUNDREDTHS OF AN INCH OR LESS. THE 12Z CMC AND 12Z NAM
MODELS SHOW A THE QPF FIELD BRUSHING A RELATIVELY GREATER FRACTION
OF THE TWIN FORKS OF LONG ISLAND AND SOUTHEAST CONNECTICUT. NO
ACCUMULATION OF SNOW EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
RIDGING AT THE SURFACE AND ALOFT FOR THE PERIOD. OUTSIDE OF SOME
AFTERNOON CUMULUS MAINLY ACROSS THE INTERIOR ZONES...PRIMARILY A
CLEAR SKY. GUIDANCE IN GOOD AGREEMENT WITH A CONTINUATION OF ABOVE
NORMAL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
12Z NAM CLEAR OUTLIER IN HOW IT IS HANDLING SYSTEM THAT WILL IMPACT
REGION WEDNESDAY NIGHT/THURSDAY SO WAS NOT USED FROM WEDNESDAY ON.
INSTEAD WITH BLEND OF MORE CONSISTENT ECMWF/SREF/CMC/GFS...THOUGH
DID LEAN TOWARD SLOWER TIMING IN ECMWF/SREF WITH THIS SYSTEM.
THE REGION SHOULD BE DRY WEDNESDAY WITH A DEEP LAYERED RIDGE
BUILDING IN...ASSOCIATED SUBSIDENCE SHOULD LIMIT MIXING TO AROUND
925 HPA...AND HELP SLOW BUILD IN OF OVER RUNNING CLOUDS AHEAD OF THE
SYSTEM AS IT MOVES INTO THE SOUTHERN APPALACHIANS.
USED A BLEND OF MAV/MET GUIDANCE FOR HIGHS...TWEAKED SLIGHTLY TOWARD
WARMER NUMBERS DUE TO EXPECT MORE SUN THAN CLOUDS - EVEN IF FILTERED
AT TIMES. FORECASTING HIGHS AROUND 5 DEGREES ABOVE NORMAL AS A
RESULT.
OVER RUNNING STRENGTHENS FROM THE LOWER TO THE MID LEVELS WEDNESDAY
NIGHT...AS RIDGE AXIS SLOWLY LIFTS TO OUR NE. BECAUSE OF THE
RELATIVELY SLOW TIMING FOR THE RIDGE AXIS LIFTING TO THE NE...AM
SOMEWHAT CONCERNED THAT THE FORECAST COULD BE TOO AGGRESSIVE IN
BRINGING IN PRECIPITATION...ESPECIALLY BEFORE MIDNIGHT.
WITH THE COLUMN BEING FAIRLY SLOW TO MOISTEN...ESPECIALLY EASTERN
ZONES COULD SEE SOME RADIATIONAL COOLING IN THE EVENING...SO HAVE
COLDEST LOWS FORECAST OVER INTERIOR SE CT AS A RESULT WEDNESDAY
NIGHT. WOULD EXPECT TEMPERATURES TO LEVEL OFF AFTER MIDNIGHT...AND
POSSIBLY BEGIN TO RISE LATE IN THE NYC METRO. WENT WITH A MAV/MET
BLEND...WEIGHED TOWARDS COOLER NUMBERS AT A GIVEN LOCATION. THIS
STILL YIELDS VALUES 10-15 DEGREES ABOVE NORMAL.
LOW LEVEL THERMAL PROFILES IN THE GFS/ECMWF/CMC/SREF SUGGEST
NORTHERN ZONES LIKELY WILL START AS A PERIOD OF LIGHT SNOW OR A
SNOW/RAIN MIX DEPENDING ON EXACTLY HOW TEMPERATURES PLAY OUT IN THE
LOWER BOUNDARY LEVEL. AT THIS TIME THOUGH...WOULD EXPECT LITTLE OR
NO ACCUMULATION...EXCEPT FOR POSSIBLY IN ELEVATIONS ABOVE 1000 FT OR
SO.
PRECIPITATION CHANGES TO ALL RAIN THROUGHOUT DURING THURSDAY
MORNING. THE RAIN COULD BE LOCALLY HEAVY AT TIMES LATE WEDNESDAY
NIGHT/THURSDAY MORNING. SEE HYDROLOGY SECTION FOR MORE DETAILS. THE
RAIN SHOULD TAPER OFF TO SHOWERS THURSDAY AFTERNOON.
WITH SOMETHING AROUND A 995 HPA LOW FORECAST TO TRACK TO OUR S...AND
A RELATIVELY STRONG EASTERLY LOW LEVEL JET FORECAST AHEAD OF
IT...HAVE THE POTENTIAL FOR STRONG GUSTY WINDS FROM LATE WEDNESDAY
NIGHT INTO THURSDAY...FOR NOW GOING JUST BELOW ADVISORY LEVELS AS
THERE IS SOME QUESTION AS TO HOW WELL MIXED THE MARINE BOUNDARY
LAYER WILL BE...BUT IF THE GFS IS CORRECT...COULD ULTIMATELY END UP
NEEDING A WIND ADVISORY OVER LONG ISLAND/COASTAL CT/NYC ZONES.
PREFERRED BLEND IS FAIRLY CONSISTENT IN SHOWING SOME DEFORMATION
AXIS SHOWERS THURSDAY NIGHT. DIFFERENCE DO ARISE BETWEEN THE GFS AND
THE ECMWF/CMC IN THE HANDLING OF THE CUTOFF LOW THAT MOVES ACROSS
THE GREAT LAKES REGION THURSDAY NIGHT. THE GFS IS THE FASTEST TO
EJECT THE SHORTWAVE THAT DRIVES THE COASTAL LOW...AND HAVE THE
CUTOFF LOW TO THE WEST DOMINATE...WHILE THE OTHERS MOVE THE
SHORTWAVE THAT IS SUPPORTING THE COASTAL LOW ALONG SLOWER...AND
KEEPING THE INFLUENCE OF THE CUTOFF LOW SEPARATE. WENT WITH
ECMWF/CMC HANDLING OF THESE FEATURES...DUE TO CONTINUITY ISSUES
LATER IN THE FORECAST. AS A RESULT...EXPECT MORE LOW LEVEL COLD AIR
TO BUILD IN BEHIND THE COASTAL LOW THAN DEPICTED IN THE GFS...AND AS
A RESULT HAVE SHRA/SHSN MIX ACROSS INTERIOR ZONES THURSDAY
NIGHT...WITH RAIN SHOWERS ELSEWHERE.
FROM FRIDAY ON...THE GFS CONTINUES TO DEPART FROM THE ECMWF/CMC AND
ITS OWN ENSEMBLE MEAN...SO WAS NOT FOLLOWED IN MAKING THE REMAINDER
OF THE FORECAST. RELIED MAINLY ON A ECMWF/CMC BLEND...WITH SOME
WEIGHING IN OF THE GFS ENSEMBLE MEAN FROM FRIDAY-MONDAY.
COULD SEE SOME LINGERING SHSN INTERIOR/SHRA/SHSN REMAINDER FRIDAY
MORNING...ESPECIALLY OVER EASTERN ZONES...THEN SOME INSTABILITY
SHOWERS OVER NW ZONES FRIDAY AFTERNOON...IN RESPONSE TO SHORTWAVE
ROTATING AROUND BASE OF CUTOFF LOW. FOR NOW WENT DRY FRIDAY
NIGHT-SATURDAY NIGHT IN NW FLOW ALOFT...THOUGH CANNOT COMPLETELY
RULE OUT ISOLATED SHRA/SHSN WITH ANY EMBEDDED SHORTWAVES PASSING BY.
HAVE SLIGHT CHANCE POPS SUNDAY FOR SHSN WITH PASSAGE OF 500 HPA
TROUGH...HELPING TO RE-ENFORCE LOW LEVEL COLD AIR...THEN DRY BY
MONDAY AS WEAK RIDGING TO ZONAL FLOW BUILDS IN.
FOR TEMPERATURES FROM THURSDAY NIGHT ON...BLENDED MEX ENSEMBLE MEAN
WITH HPC GUIDANCE...AND TWEAKED TOWARDS 12Z ECMWF LOW LEVEL THERMAL
FIELDS. AFTER ABOVE NORMAL TEMPERATURES THURSDAY
NIGHT-FRIDAY...FORECASTING NEAR NORMAL TEMPERATURES FRIDAY
NIGHT-SATURDAY NIGHT...THEN BELOW NORMAL TEMPERATURES SUNDAY-MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
HIGH PRES CONTINUES TO MOVE OFFSHORE TONIGHT AS LOW PRES PASSES S
OF LONG ISLAND. THIS LOW WILL STRENGTHEN AS IT MOVES OUT TO SEA
AS ANOTHER MOVES ACROSS SE CANADA ON TUE RESULTING IN INCREASING
W-NW WINDS WHILE ANOTHER AREA OF HIGH PRES APPROACHES FROM THE
WEST.
CIGS HAVE DROPPED TO LOW VFR. A PERIOD OF MVFR CIGS IS NOW
EXPECTED AT COASTAL TERMINALS THROUGH 10Z OR 11Z BASED ON UPSTREAM
OBS...BUT SHOULD REMAIN ABOVE 2K FT. ONE OTHER EXCEPTION IS
BETWEEN 11Z AND 14Z WHERE AN INCREASE IN LOW LEVEL MOISTURE AND
SHARP LOW LEVEL INVERSION MAY PRODUCE A PERIOD OF LOW MVFR OR EVEN
IFR CIGS. MODELS HAVE BEEN FLIP FLOPPING ON THIS AND CONFIDENCE
REMAINS LOW...THEREFORE CONTINUED WITH THE SCT CLOUD GROUP.
PRECIP ASSOCIATED WITH LOW PASSING TO THE S IS
REMAINING S AS EXPECTED. COULD SEE A FEW FLURRIES OVERNIGHT AS AN
UPPER DISTURBANCE MOVES THROUGH...BUT NOT EXPECTING THIS TO CAUSE
ADDITIONAL RESTRICTIONS.
WINDS INCREASE TUE AFTN AS THE PRES GRADIENT TIGHTENS WITH THE LOW
STRENGTHENING AS IT MOVES OUT TO SEA AND ANOTHER MOVES ACROSS SE
CANADA. GUSTS INTO THE LOWER 20S ARE EXPECTED AFT 16Z AND PK WINDS
MAY OCNLY REACH 25 KT.
NYC TERMINALS: DIRECTIONS WILL BE RIGHT AROUND 300 DEGREES TRUE
BETWEEN 18Z AND 00Z...THEN VEER TO THE RIGHT OF 300.
OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...
TUE NIGHT-WED...VFR.
WED NIGHT-THU...OCNL IFR IN RAIN. GUSTY NE-E WINDS.
FRI...CHANCE FOR IFR OR MVFR IN SNOW SHOWERS. GUSTY NW-W WINDS.
SAT...VFR. GUSTY NW-W WINDS.
&&
.MARINE...
LIGHT WINDS EXPECTED FROM THE SOUTHWEST TONIGHT. AN AREA OF LOW
PRESSURE WILL PASS WELL OFFSHORE LATE TONIGHT...THEN THE PRESSURE
GRADIENT TIGHTENS TUESDAY MORNING WITH HIGH PRESSURE BUILDING IN
FROM THE WEST BEHIND THE STORM AS WELL AS BEHIND ANOTHER AREA OF LOW
PRESSURE MOVING ACROSS EASTERN CANADA. GUSTS TO 25 KTS ARE EXPECTED
TO DEVELOP ON THE OCEAN WATERS AND EASTERN LONG ISLAND SOUND BY
MIDDAY ON TUESDAY...AND LAST INTO THE EVENING HOURS WITH COLD AIR
ADVECTION. SEAS EXPECTED TO BUILD TO 5 FT OVER ANZ353 AND
ANZ350...BUT PROBABLY ENDS UP JUST BELOW IT AT ANZ355. PERHAPS
EASTERNMOST PORTIONS OF ANZ355 COULD TOUCH 5 FT AT TIMES. THE
PRESSURE GRADIENT RELAXES LATER ON TUESDAY NIGHT...WITH SCA
CONDITIONS COMING TO AN END ACROSS ALL WATERS.
SUB-SMALL CRAFT CONDITIONS ON WEDNESDAY...GIVE WAY TO RAPIDLY
BUILDING WINDS AND SEAS WEDNESDAY NIGHT...DUE TO APPROACHING COASTAL
LOW. COULD SEE GUSTS TO GALE FORCE LATE WEDNESDAY NIGHT...DEPENDING
ON HOW MUCH OF 40-50 KT 950-925 HPA JET MIXES DOWN. COASTAL LOW
TRACKS TO THE S THURSDAY...WITH POTENTIAL FOR GALES THROUGH AT LEAST
THE MORNING HOURS. SMALL CRAFT ADVISORY CONDITIONS THEN EXPECTED TO
LINGER...ESPECIALLY ON THE COASTAL OCEAN/EASTERN WATERS INTO FRIDAY.
ALL WATERS SHOULD FALL BELOW SCA LEVELS SATURDAY AS HIGH PRESSURE
GRADUALLY BUILDS IN.
&&
.HYDROLOGY...
A TRACE TO A FEW HUNDREDTHS OF LIQUID EQUIVALENT IS POSSIBLE TNGT
ACROSS LONG ISLAND AND SOUTHEASTERN CONNECTICUT.
THERE IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL FROM LATE
WEDNESDAY NIGHT INTO THURSDAY MORNING. FOR NOW FORECASTING GENERALLY
FROM 1/2-3/4 AN INCH OF RAINFALL WEDNESDAY NIGHT/THURSDAY...BUT
DEPENDING ON EXACTLY WHERE THE HEAVIEST RAINBANDS SET UP LATE
WEDNESDAY NIGHT/THURSDAY MORNING...SOME LOCATIONS COULD SEE UP TO
DOUBLE THAT...AND MAYBE A BIT MORE. SO WHILE FOR THE MOST PART...AT
MOST MINOR POOR DRAINAGE/URBAN FLOODING IS EXPECTED...THERE COULD BE
LOCALIZED FLOODING OF POOR DRAINING/URBAN AREAS IF THEY ARE UNDER
THE HEAVIEST RAINBANDS. AT THIS TIME IT IS TOO SOON TO PINPOINT THE
EXACT LOCATIONS THESE RAINBANDS WILL FORM OVER...JUST THAT
CONDITIONS ARE FORECAST TO EXIST THAT ARE CONDUCIVE TO THEIR
FORMATION OVER SOME PORTION OF THE TRI-STATE LATE WEDNESDAY
NIGHT/THURSDAY MORNING.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR ANZ330-355.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 1 AM EST
WEDNESDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
906 PM EST WED JAN 11 2012
.UPDATE...
FORECAST IS ON TRACK TONIGHT. WILL CONTINUE TO SEE EXTENSIVE CLOUD
COVERAGE OVERNIGHT BUT FOR THE MOST PART THE PRECIP HAS LIFTED OUT
OF THE AREA. RUC PROGS A WEAK VORT MAX QUICKLY MOVING ACROSS THE
STATE OVER THE NEXT FEW HOURS...BUT SEEING AS THIS ISNT PRODUCING
SHOWERS IN AL...DO NOT EXPECT TO SEE ANY SHOWERS ASSOCIATED WITH
IT HERE. CUT BACK ON POPS OVERNIGHT AND ONLY LEFT THEM IN ACROSS
NORTHEAST GEORGIA. DID ADD PATCHY DRIZZLE THOUGH TONIGHT FOR
EXTREME NORTH GEORGIA.
11
&&
.PREV DISCUSSION...
SHORT TERM /TONIGHT THROUGH FRIDAY/...
/ISSUED 254 PM EST WED JAN 11 2012/
SHOWERS AND ISOLATED THUNDERSTORMS REMAINED ACROSS NORTH GEORGIA
THIS AFTERNOON AS A RESULT OF LOW PRESSURE MOVING THROUGH THE
AREA. ASSOCIATED COLD FRONT EXPECTED TO MOVE INTO THE CAROLINAS
THIS EVENING WILL HAVE LITTLE IMPACT TO THE CWA...AHEAD OF A
SECOND COLD FRONT THAT WILL QUICKLY PUSH THROUGH ON THURSDAY.
INITIALLY...WRAP AROUND MOISTURE WILL KEEP NORTH GEORGIA IN A
FAVORABLE PRECIP AREA...BUT THIS MOISTURE...COMBINED WITH THE
SOUTHERLY FLOW AHEAD OF THE NEXT FRONT...WILL BE ENOUGH TO KEEP
SLIGHT CHANCE TO CHANCE POPS ACROSS MAINLY NORTH GEORGIA THROUGH
THURSDAY AFTERNOON. BEHIND THIS BOUNDARY...MUCH COOLER
TEMPERATURES MOVE INTO THE AREA...WHICH WITH SOME RESIDUAL
MOISTURE...WILL BE ENOUGH TO PRODUCE LIGHT SNOW ACROSS NORTH
GEORGIA. HAVE GONE WITH GENERALLY SLIGHT CHANCE TO CHANCE LIGHT
SNOW ACROSS THE NORTHERNMOST TIER OF COUNTIES. MODELS ARE IN
FAIRLY GOOD AGREEMENT WITH THIS SOLUTION...AND DUE TO
INCONVENIENCES THAT MAY RESULT FROM THIS PRECIP...CONFIDENCE IS
HIGH ENOUGH TO GO AHEAD AND ISSUE THE WINTER WEATHER ADVISORY FOR
00Z TO 12Z FRIDAY. HPC WWD HAS THE AREA OUTLOOKED FOR 1 INCH OF
ACCUMULATIONS...AND HAVE GENERALLY SIDED MORE TOWARDS THE 0.5 TO 1
INCH RANGE...WITH THE HIGHER AMOUNTS IN THE HIGHER ELEVATIONS.
WITH WARM SURFACE TEMPERATURES...MOST OF THE ACCUMULATIONS WILL BE
ON THE ELEVATED SURFACES.
ADDITIONALLY...THE TIGHT PRESSURE GRADIENT OVER THE AREA RESULTING
FROM THESE SERIES OF SYSTEMS WILL ALLOW FOR STRONG TO GUSTY WINDS TO
IMPACT THE AREA ON THURSDAY. EXPECTING WINDS TO BE IN THE 15 TO 20
MPH RANGE...WITH GUSTS AS HIGH AS 35 MPH. HAVE ISSUED A WIND
ADVISORY FOR ALL OF NORTH AND CENTRAL GEORGIA FOR 10 AM THURSDAY
THROUGH MIDNIGHT.
ONCE THE COLD FRONT PUSHES THROUGH THE STATE THURSDAY...ASSOCIATED
PARENT LOW SWEEPS OVER NEW ENGLAND...AND PULLS ANY REMAINING WRAP
AROUND MOISTURE UP THE APPALACHIANS DURING THE DAY FRIDAY. SURFACE
HIGH PRESSURE BUILDS BACK INTO THE STATE...WITH DRY AND CHILLY
CONDITIONS PREVAILING ACROSS THE STATE.
MET OUT PERFORMED THE MAV ON THE TEMPERATURES YESTERDAY...AND EACH
HAS ITS STRENGTHS WITH THE CURRENT FORECAST...ONE BETTER ON
TEMPS...THE OTHER SEEMINGLY BETTER ON DEW POINTS. HAVE GENERALLY
GONE WITH A BLEND OF THE TWO...AND HEAVILY WEIGHTING THE LOCAL BIAS
NUMBERS. AS A RESULT...EXPECTING ONE LAST DAY WITH HIGHS IN THE MID
50S TO MID 60S ON THURSDAY. INFLUENCE OF THE COLD FRONT REALLY
PROMINENT ON FRIDAY MORNING AS TEMPS DROP INTO THE 20S AND LOW
30S...AND WITH HIGHS ONLY IN THE 40S FRIDAY AFTERNOON.
31
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED 254 PM EST WED JAN 11 2012/
SURFACE HIGH PRESSURE CONTROLS THE ENVIRONMENT THROUGH EARLY
WEEK...WITH DRY CONDITIONS PREVAILING...AND CHILLY TEMPERATURES
GRADUALLY WARMING. NEXT FRONTAL SYSTEM LOOKS TO MOVE INTO
NORTHWEST GEORGIA THROUGH EARLY TUESDAY. HAVE MADE NO MAJOR
CHANGES TO THE CURRENT FORECAST...AND SLIGHT CHANCE TO CHANCE POPS
ARE STILL EXPECTED TUESDAY AS THIS NEXT SYSTEM ENTERS THE REGION.
31
AVIATION...
00Z UPDATE...
/ISSUED 710 PM EST WED JAN 11 2012/
SHORT WAVE AND ASSOCIATED -SHRA LIFTING OUT OF GEORGIA TO THE
NORTHEAST. MID-LEVEL DRYING IS ENCROACHING...BUT MVFR CIGS WILL
CONTINUE THROUGH THE NIGHT. MAY SEE BREAKS IN CIGS
MID-MORNING...BUT RAPID REDUCTION AND -SHRA AGAIN AS STOUT COLD
FRONT PUSHES THROUGH. GUSTS TONIGHT EXPECTED TO STAY BELOW
15KTS...BUT THEN JUMP TO NEAR 30KTS WITH FRONT AROUND 21Z.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM ON CIGS AND GUSTS TONIGHT.
HIGH FOR REMAINING ELEMENTS.
27
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 43 63 28 47 / 10 20 10 0
ATLANTA 43 58 28 45 / 10 30 10 0
BLAIRSVILLE 42 50 23 37 / 20 50 30 0
CARTERSVILLE 41 57 29 43 / 10 30 20 0
COLUMBUS 42 64 29 49 / 0 20 5 0
GAINESVILLE 43 53 30 42 / 10 30 20 0
MACON 40 65 30 50 / 0 20 10 0
ROME 44 56 28 42 / 10 50 20 0
PEACHTREE CITY 38 59 26 46 / 5 20 10 0
VIDALIA 43 68 31 51 / 5 5 10 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THURSDAY TO MIDNIGHT EST THURSDAY NIGHT
FOR THE FOLLOWING ZONES: BALDWIN...BANKS...BARROW...BARTOW...
BIBB...BLECKLEY...BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...
CHATTOOGA...CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...
CRAWFORD...CRISP...DADE...DAWSON...DEKALB...DODGE...DOOLY...
DOUGLAS...EMANUEL...FANNIN...FAYETTE...FLOYD...FORSYTH...
GILMER...GLASCOCK...GORDON...GREENE...GWINNETT...HALL...
HANCOCK...HARALSON...HARRIS...HEARD...HENRY...HOUSTON...
JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...
LAURENS...LUMPKIN...MACON...MADISON...MARION...MERIWETHER...
MONROE...MONTGOMERY...MORGAN...MURRAY...MUSCOGEE...NEWTON...
NORTH FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...
PICKENS...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...SCHLEY...
SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TOWNS...TREUTLEN...
TROUP...TWIGGS...UNION...UPSON...WALKER...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WHITE...WHITFIELD...WILCOX...
WILKES...WILKINSON.
WINTER WEATHER ADVISORY FROM 7 PM THURSDAY TO 7 AM EST FRIDAY
FOR THE FOLLOWING ZONES: CATOOSA...DADE...FANNIN...GILMER...
LUMPKIN...MURRAY...TOWNS...UNION...WALKER...WHITE...WHITFIELD.
&&
$$
11
AREA FORECAST DISCUSSION
NWS LINCOLN IL
845 PM CST WED JAN 11 2012
.DISCUSSION...
ISSUED 845 PM CST WED JAN 11 2012
QUICK GLANCE AT THE 00Z NAM...AS WELL AS THE HRRR AND RUC MODELS...
INDICATES NO BIG CHANGES NEEDED TO HEADLINES OR SNOW SCENARIO
FORECAST. COLD FRONT NOW APPROACHING THE IL RIVER WITH GUSTY
NORTHWEST WINDS AND LOW CLOUDS. RADARS INDICATE THE SNOW IS LAGGING
BACK OVER CENTRAL IA...SO NO POPS THIS EVENING STILL LOOK ON TRACK.
THE NAM AND HRRR MODELS INDICATE THE LEADING EDGE OF THE SNOW
REACHING THE MIDDLE OF THE FORECAST AREA BY 12Z. WATER VAPOR LOOPS
SHOWING THE DEEPENING/AMPLIFYING TROUGH OVER THE PLAINS...WITH
INCREASING INFLECTION OVER NEB BEING THE BEGINNINGS OF THE LOW
CLOSING OFF. THE EXPANDING DARK AREA ON SATELLITE ALONG THE TROF
AXIS AND DOWN INTO THE INFLECTION OVER SOUTHERN NEB AND NORTHWESTERN
KS SUGGESTS THAT STRATOSPHERIC POTENTIAL VORTICITY IS POKING
DOWNWARD ON THE WESTERN FLANK OF THE TROUGH...WHICH WILL ACT TO
ACCELERATE THE DEEPENING PROCESS.
MOST OF THE SYNOPTIC MODEL OUTPUT AGREES ON TRACKING THE CENTER OF
THE DEEPENING UPPER LOW ACROSS THE SOUTHERN THIRD OF IL FROM LATE
MORNING TO LATE AFTERNOON THURSDAY. DURING THAT TIME...PV AND
DIFLUENCE WILL BE ROTATING THROUGH THE EASTERN QUADRANT AND INTO THE
NORTHEASTERN QUADRANT OF THE LOW...WHICH WILL EXTEND EAST/WEST
THROUGH CENTRAL IL. IN ADDITION...ISENTROPIC ANALYSES INDICATE A
DECENT UPGLIDE ON THE 300K-290K SURFACES IN THE SAME GENERAL
AREA...WITH SPECIFIC HUMIDITIES OF 1.5-2.5 G/KG. SO SNOW AMOUNTS OF
3-5 INCHES OVER THE NORTHERN HALF OF THE AREA STILL LOOK GOOD...WITH
POSSIBLE MESOSCALE ENHANCEMENT OF SNOW BANDS.
WILL FRESHEN UP THE WINTER WEATHER ADVISORY PRODUCT SHORTLY.
04
&&
.AVIATION...
ISSUED 515 PM CST WED JAN 11 2012
RAIN ASSOCIATED WITH THE OH VALLEY SYSTEM IS EXITING EASTERN IL AND
SHOULD NOT AFFECT TAF SITES. THE CLEARING TREND IN THE MVFR STRATOCU
HAS SLOWED UP SOMEWHAT SO WILL MAINTAIN A MENTION IN THE DEC/CMI
TAFS FOR THE FIRST COUPLE OF HOURS. OUT WEST...STRONGLY AMPLIFYING
UPPER TROUGH IS COMING SOUTHEASTWARD ACROSS THE NORTHERN PLAINS.
LEAD COLD FRONT HAS PROGRESSED INTO EASTERN IA AND WILL MAKE IT TO
PIA 04Z-05Z TONIGHT...THEN THROUGH THE REMAINDER OF THE TAF SITES
BEFORE 12Z. 1K-2K FT STRATOCU WILL ARRIVE COINCIDENTAL WITH THE
FRONT ALONG WITH GUSTY NORTHWEST WINDS...WITH SNOW BEGINNING 5HR-6HR
THEREAFTER. IFR OR LOWER CONDITIONS WILL THEN BE COMMON ON THU WITH
NORTHWEST WINDS INCREASING AS THE SURFACE PRESSURE GRADIENT
TIGHTENS. EXPECT GUSTS BY THEN AT 30-35 KT. BY MIDDAY THE
COMBINATION OF SNOW...FOG...AND BLOWING SNOW WILL KEEP VISIBILITIES
AT OR BELOW A MILE. SOME CHANCE OF IMPROVING CONDITIONS AT THE VERY
END OF THE TAF PERIOD FOR PIA/SPI...BUT TOO CLOSE TO ADDRESS IN THIS
TAF CYCLE.
04
&&
.PREV DISCUSSION...
ISSUED 220 PM CST WED JAN 11 2012
SNOW...WIND AND MUCH COLDER WEATHER HEADING FOR CENTRAL...EAST
CENTRAL AND SOUTHEAST ILLINOIS THURSDAY INTO FRIDAY.
SOUTHERN STREAM SHORTWAVE AND ASSOCIATED SURFACE LOW SOUTH OF THE
OHIO RIVER SPREAD RAIN AS FAR NORTH AS SPRINGFIELD EAST NORTHEAST TO
CHAMPAIGN. FURTHER NORTH AND WEST...SUNSHINE HAS BROUGHT EARLY
AFTERNOON TEMPERATURES INTO THE MID AND UPPER 50S. THE COLD FRONT
WHICH WILL BRING A DRASTIC CHANGE IN OUR WEATHER AS PUSHING THRU
CENTRAL IOWA EARLY THIS AFTERNOON WITH TEMPERATURES STRUGGLING THRU
THE SINGLE DIGITS AND LOW TEENS OVER THE DAKOTAS.
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
SNOW AMOUNTS...FALLING TEMPERATURES AND GUSTY WINDS THE MAIN FORECAST
CONCERN THROUGH LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING.
CONDITIONS ARE EXPECTED TO DETERIORATE RAPIDLY TOMORROW MORNING
WEST...AND OVER THE EAST BY EARLY AFTERNOON.
MODELS IN DECENT AGREEMENT WITH THE MOVEMENT OF THE SOUTHERN STREAM
UPPER LEVEL WAVE AS IT GETS ABSORBED BY THE STRONGER NORTHERN STREAM
ENERGY LATER TOMORROW WHICH IN EFFECT WILL PRODUCE A DEEPENING
SURFACE WAVE WHICH IS FORECAST TO TRACK NORTH INTO EASTERN LOWER
MICHIGAN BY 00Z FRIDAY. SNOW SHOULD TRACK INTO FAR WESTERN IL
BETWEEN 09Z AND 12Z AFFECTING THE MORNING COMMUTE MAINLY IN AREAS
WEST OF INTERSTATE 55 WITH LOCATIONS TO THE EAST SEEING THE SNOW
DEVELOP BY MID TO LATE MORNING. THE COMMUTE HOME TOMORROW EVENING
LOOKS TO BE A REAL MESS. NAM-WRF TIME HEIGHT CROSS SECTIONS SHOWING
THE BEST DEEP LAYERED MOISTURE AND OMEGA COINCIDENT WITH THE SNOW
GROWTH REGION TO BE OCCURRING FROM MID MORNING TO LATE AFTERNOON
WEST AND LATE MORNING INTO THE EVENING HOURS EAST. TEMPERATURES THRU
THE DAY WILL BE STEADY OR SLOWLY FALLING WITH FRIDAY MORNING LOWS IN
THE 10 TO 15 DEGREE RANGE.
LOOKING AT BOTH THE NAM AND GFS ISENTROPIC PROFILES AT 290K...SUGGEST
THE BEST ASCENT AND LOWEST PRESSURE DEFICITS OCCUR IN THE 00Z TO 06Z
TIME FRAME WITH THE BETTER LIFT SHIFTING OFF TO OUR EAST LATE
THURSDAY NIGHT/FRIDAY MORNING. MODELS SUGGEST SOME DECENT 850-500 MB
FRONTOGENETICAL FORCING COUPLED WITH WEAK STATIC STABILITY
INDICATING THE POTENTIAL FOR SOME BANDED SNOWFALL...ESPECIALLY
ACROSS OUR NORTH LATER TOMORROW MORNING INTO THE AFTERNOON HOURS.
SNOW RATIOS START OUT AT 13:1 BUT FORECAST SOUNDINGS SUGGEST 16:1 OR
EVEN GREATER TOWARDS LATE THU AFTN AND EVENING. HIGHEST SNOW AMOUNTS
CONTINUE TO BE ALONG AND NORTH OF I-74 WHERE 3 TO 5 INCHES WILL
OCCUR...WITH SOME LOCALLY HIGHER AMOUNTS POSSIBLE...ESPECIALLY IN
OUR FAR NORTHEASTERN AREAS. FURTHER SOUTH...TOTAL SNOW AMOUNTS LOOK
TO BE IN THE ORDER OF 1 TO 3 INCHES WITH AN INCH OR TWO ALONG AND
SOUTH OF I-70. ISSUED THE WINTER WEATHER ADVISORY EARLIER AND WILL
CONTINUE WITH IT ACROSS THE ENTIRE FORECAST AREA INTO FRIDAY
MORNING. AS THE SURFACE SYSTEM DEEPENS LATER TONIGHT INTO THUR...NW
WINDS WILL INCREASE TO BETWEEN 20 TO 25 MPH...WITH OCCASIONAL GUSTS
APPROACHING 35 MPH...PRODUCING QUITE A BIT OF BLOWING SNOW. WINDS
SHOULD GRADUALLY DECREASE FRIDAY MORNING AS THE LOW PULLS WELL OFF
TO OUR EAST. WIND CHILLS DROP INTO THE SINGLE DIGITS NORTHWEST BY
TOMORROW AFTN...AND DOWN TO BETWEEN -3 TO -8 FRIDAY MORNING.
TRANQUIL WEATHER WILL RETURN FRIDAY AFTN INTO FRIDAY NIGHT WITH SOME
RATHER NIPPY TEMPERATURES IN STORE FOR THE AREA...ESPECIALLY WITH A
FRESH SNOW PACK IN PLACE. WENT BELOW MOST GUID VALUES FRI NIGHT/SAT
MORNING WITH OUR NORTH SEEING SINGLE DIGITS FOR LOWS. HOWEVER...IF
OUR NEXT WEATHER SYSTEM TRACKING IN FROM THE NORTHWEST ON SATURDAY
IS QUICKER THAN WHAT MODELS INDICATE...CLOUDS MAY GET INTO THE AREA
FASTER WHICH WOULD HELP KEEP THE TEMPS UP. FOR NOW... WL GO WITH THE
COLDER LOWS EARLY SATURDAY MORNING. CLIPPER SYSTEM TRACKING QUICKLY
SOUTHEAST INTO THE AREA ON SATURDAY BRINGING A THREAT OF LIGHT SNOW
TO THE AREA...ESPECIALLY ACRS THE NORTHEAST HALF OF THE FORECAST
AREA. GFS AND ECMWF IS FURTHEST SOUTH WHICH WOULD BRING SOME LIGHT
ACCUMULATING SNOWS TO OUR NORTH...WHILE THE NAM WAS A BIT FURTHER
NORTH AND NOT NEARLY AS AGGRESSIVE WITH THE QPF. FOR NOW...WILL KEEP
LOW CHANCE POPS GOING ACRS THE NORTH AND EAST.
LONG TERM...SUNDAY THROUGH WEDNESDAY
UPPER LEVEL HEIGHTS REBOUND OVER THE MIDWEST SUNDAY INTO MONDAY
WHICH WILL SPELL WARMER WEATHER RETURNING TO THE AREA. DESPITE THE
SNOW COVER...WE SHOULD SEE AFTERNOON TEMPS PUSH BACK INTO THE UPPER
20S TO MIDDLE 30S ON SUNDAY...AND UPPER 30S TO MIDDLE 40S BY MONDAY
WITH INCREASING SOUTHERLY WINDS. OUR NEXT WEATHER SYSTEM LOOKS TO
AFFECT THE AREA LATE MONDAY INTO MONDAY NIGHT WITH TEMP PROFILES
WARM ENOUGH TO SUPPORT MOSTLY RAIN WITH POSSIBLY A CHANGEOVER TO
LIGHT SNOW OR FLURRIES AS THE SYSTEM PULLS AWAY AND COLDER AIR IS
DRAWN SOUTHEAST INTO OUR AREA ON TUES. AFTER A BRIEF SHOT OF COLD
AIR MIDWEEK...A MORE ZONAL FLOW PATTERN WILL DEVELOP ACROSS THE
LOWER 48 RESULTING IN TEMPS AOA NORMAL FOR THE REMAINDER OF THE WEEK.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO 9 AM CST FRIDAY
FOR ILZ038-043>046-052>057-061>063-066>068-071>073.
WINTER WEATHER ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY
FOR ILZ027>031-036-037-040>042-047>051.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
704 PM CST WED JAN 11 2012
.UPDATE...
MESOSCALE MODELS INCLUDING THE HRRR...NAM12...AND RUC ALL CONTINUE
TO SHOW A NARROW BAND OF MUCH STRONGER FORCING ALIGNED ALONG THE
MISSISSIPPI RIVER DURING THE 10Z TO 20Z PERIOD THURSDAY. OUR BROAD
ADVISORY STILL LOOKS VERY MUCH ON TRACK WITH A WIDESPREAD 3 TO 5
INCH SNOWFALL EVENT...WITH PLENTY OF WIND/CONSIDERABLE DRIFTING
ISSUES EXPECTED. I HAVE HIGHLIGHTED THE EXPECTED MORE INTENSE BAND
IN OUR WSW PRODUCTS ON THE LATEST UPDATE...AS SHOULD THIS
VERIFY...A NARROW AXIS OF WARNING CRITERIA SNOWFALL OF 5 TO 8
INCHES IS POSSIBLE WITHIN 30 MILES EITHER SIDE OF THE MISSISSIPPI
RIVER FROM GENERALLY THE QUAD CITIES METRO AREA TO DUBUQUE. AN
UPGRADE TO WARNING IS POSSIBLE LATER THIS EVENING IF UPPER AIR
DATA AND NEW 00Z MODEL DATA SHOW THIS SIMILAR
SIGNATURE...INCREASING CONFIDENCE ON THE EXACT LOCATION OF WHAT IS
ALREADY BEING DESCRIBED AS...LOCALLY HIGHER AMOUNTS POSSIBLE...IN
OUR PRODUCTS.
..ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR CLINTON-JACKSON-SCOTT.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST THURSDAY NIGHT FOR
BENTON-BUCHANAN-CEDAR-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-VAN BUREN-WASHINGTON.
IL...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR BUREAU-CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-
MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-
WHITESIDE.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST THURSDAY NIGHT FOR
CLARK-SCOTLAND.
&&
$$
ERVIN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
520 PM CST WED JAN 11 2012
.AVIATION...
VFR WX WILL NOT LAST LONG THIS EVENING...AS MVFR CIGS AROUND 1500
FT RAPIDLY SPREAD ACROSS ALL OF EASTERN IOWA AND NORTHWEST
ILLINOIS. AS THE CLOUDS ARRIVE...NORTHWEST WINDS WILL INCREASE TO
AROUND 20 TO 25 KTS...GUSTING TO 30 TO 35 KTS. THESE STRONG WINDS
WILL CONTINUE THROUGH THE DAY THURSDAY. SNOW WILL SPREAD OVER
EASTERN IOWA AND NORTHWEST ILLINOIS BY MIDNIGHT...AND BECOME
MODERATE AT TIMES THROUGH MID MORNING IN EASTERN IOWA...AND
MODERATE AT TIMES THROUGH THE ENTIRE DAY THURSDAY FOR LOCATIONS
ALONG THE MISSISSIPPI RIVER...MLI...BRL...DBQ. VISIBILITIES AND
CIGS WILL BE IFR AT TIMES...WITH A PERIOD OF LIKELY LIFR WITH SNOW
AND BLOWING SNOW POSSIBLE 2 TO 3 HOURS EITHER SIDE OF SUNRISE
THURSDAY MORNING. DEPENDING ON SNOW DEPTH AT AIRPORTS...BLOWING
SNOW MAY CONTINUE TO COMBINE WITH FALLING SNOW THROUGH THURSDAY
EVENING TO REDUCE VISIBILITIES.
..ERVIN..
&&
.PREV DISCUSSION... /ISSUED 300 PM CST WED JAN 11 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB POLAR FRONT RUNNING FROM A LOW NEAR
THE MINNESOTA ARROWHEAD SOUTHWEST INTO NEW MEXICO. A CUT OFF LOW
WAS OVER THE TENNESSEE VALLEY DRIFTING TO THE NORTHEAST. SATELLITE
AND RADAR TRENDS THROUGH EARLY AFTERNOON SHOW CLOUDS MOVING EAST
ACROSS IOWA WITH A BAND OF SNOW FROM MINNESOTA INTO WESTERN IOWA
AND EASTERN NEBRASKA.
18Z SFC ANALYSIS HAD A SERIES OF LOW IN NORTHERN WISCONSIN WITH A
PRE-FRONTAL TROF THROUGH EASTERN IOWA AND INTO CENTRAL OKLAHOMA.
THE POLAR FRONT RAN FROM JUST EAST OF KDLH...TO KMCI...TO KCDS.
DEW POINTS ALONG THE FRONT WERE IN THE 30S WITH 20S OUT AHEAD OF
IT. BEHIND THE POLAR FRONT...DEW POINTS QUICKLY DROPPED OFF INTO
THE 20S AND TEENS.
SHORT TERM...TONIGHT AND THURSDAY
COMPRESSIONAL HEATING AHEAD OF THE POLAR FRONT HAS RESULTED IN
RECORD HIGHS BEING EITHER TIED OR BROKEN TODAY. SEE THE CLIMATE
SECTION BELOW FOR SPECIFIC RECORDS.
THE WINTER STORM WATCH HAS BEEN UPGRADED TO A WINTER WEATHER ADVISORY.
BASED ON THE SYSTEM BEING A BIT SLOWER AND DIGGING A LITTLE
FURTHER TO THE SOUTH/WEST...THE START TIME OF SOME ADVISORY
HEADLINES FOR AREAS ALONG/EAST OF THE MISSISSIPPI HAVE BEEN PUSHED
BACK TO MIDNIGHT.
THE POLAR FRONT SHOULD REACH THE BULK OF THE MISSISSIPPI RIVER
RIGHT AROUND SUNSET AND SHOULD EXIT THE EASTERN CWFA JUST BEFORE
MIDNIGHT. SINCE THE SYSTEM CONTINUES TO SHOW SOME NON-LINEARITY
ASPECTS TO IT...THE RUC HAS BE VERY USEFUL IN THE IMMEDIATE SHORT
TERM.
PER THE RUC...CONDENSATION PRESSURE DEFICITS START COLLAPSING THIS
EVENING IN THE FAR WESTERN CWFA AS THE FORCING INCREASES. BY 9
PM...A BAND OF SNOW WILL BE OVER ROUGHLY THE WESTERN THIRD TO 40
PERCENT OF THE CWFA. STARTING AROUND 9 PM...THE RUC INDICATES A
DEFORMATION ZONE WILL BEGIN DEVELOPING OVER EASTERN IOWA AS THE
UPPER LEVEL SYSTEM STRENGTHENS. BY MIDNIGHT...SNOW WILL BE WIDESPREAD
GENERALLY WEST OF A KDBQ TO KEOK LINE.
AFTER MIDNIGHT...THE OVERALL FORCING CONTINUES TO STRENGTHEN AS
THE DEFORMATION ZONE BECOMES FULLY EVOLVED. BY SUNRISE...SNOW
SHOULD BE WIDESPREAD ACROSS THE ENTIRE CWFA.
SNOWFALL AMOUNTS TONIGHT SHOULD RANGE FROM 0.5 INCHES IN THE
EXTREME EASTERN CWFA TO 2.5 INCHES IN THE FAR WESTERN CWFA.
SNOW/RAIN RATIOS WILL INITIALLY START OUT CLOSE TO
CLIMATOLOGY...OR ROUGHLY 13 TO 1 AND WILL INCREASE LATER TONIGHT
INTO THURSDAY.
BASED ON THE OVERALL FORCING...THE PERIOD FROM MIDNIGHT TO ABOUT NOON
THURSDAY WILL BE WHEN A MAJORITY OF THE SNOW WILL FALL.
ON THURSDAY...SNOW WILL BE WIDESPREAD ACROSS THE AREA DURING THE
MORNING HOURS WITH THE DEFORMATION ZONE OVER THE AREA. DURING THE
AFTERNOON THE SNOW INTENSITY WILL DECREASE ACROSS THE WESTERN CWFA
WHILE CONTINUING IN THE EASTERN PARTS.
SNOW AMOUNTS ON THURSDAY WILL BE AN ADDITIONAL 1 TO 4 INCHES WITH
A GRADIENT RUNNING FROM WEST TO EAST.
SINCE THE SNOW WILL BE QUITE DRY...CONSIDERABLE DRIFTING WILL BE
SEEN...ESPECIALLY IN RURAL AND OPEN AREAS. WINDS SHOULD BE 20 TO
30 MPH WITH GUSTS TO AROUND 35 MPH. WHILE BLOWING SNOW MAY
OCCUR...IT SHOULD BE PATCHY IN NATURE IN THE RURAL AREAS.
..08..
LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY
ACTIVE PATTERN BUT NO SIGNIFICANT SYSTEMS SUGGESTED ATTM.
SNOW IS EXPECTED TO TAPER TO FLURRIES THU EVE WITH LITTLE ADDITIONAL
ACCUMS. LINGERING GUSTY WINDS MAY PRODUCE SOME DRIFTING AND POSSIBLY
PATCHY BLOWING SNOW.
FRI-FRI NGT... WINDS GENERALLY BRISK AT 10-20 MPH DURING DAY WITH
CLOUDS AND FLURRIES POSSIBLE WITH ADDITIONAL ENERGY DIGGING DOWN
BACKSIDE OF DEPARTING STORM SYSTEM. HIGHS ONLY RECOVERING IN TEENS
AND 20S. SOME CLEARING FRI NGT BUT APPEARS SHORT LIVED AS WARM
ADVECTION MID/HIGH CLOUDS QUICKLY ON HEELS OF ANY CLEARING ATTENDANT
TO NEXT APPROACHING SHORTWAVE /CLIPPER SYSTEM/. CLOUD TRENDS MAKE
MIN TEMP FCST CHALLENGING. ANTICIPATE WINDS TO DIE OFF IN EVE AND AT
LEAST PARTIAL CLEARING FOR WIDESPREAD SINGLE DIGITS... POSSIBLY AT
OR BELOW ZERO IN SOME AREAS N/E... BEFORE CLOUDS INCREASE.
SAT-SAT NGT... CLIPPER SYSTEM EXPECTED TO PASS MAINLY DURING DAY. JET
STRUCTURE NOT THAT IMPRESSIVE AND MOISTURE LACKING SO FAVOR THE
WEAKER HI-RES ECMWF FOR MAINLY FLURRIES WITH CHC OF -SN.
SUN-SUN NGT... GENERALLY DRY WITH MODERATING TEMPS AS HEIGHTS BUILD
ALOFT WITH CHALLENGE BEING RESIDUAL SNOW COVER AND IMPACT ON TEMPS.
MAY SEE NON-DIURNAL TREND AT NGT WITH TEMPS SLOWLY RISING WITH
CONTINUED LOW LEVEL WARM ADVECTION.
MON-WED... NEXT FRONT TO PASS MON-MON NGT WITH CHC OF PCPN. MODELS
SHOWING SUFFICIENT WARMING AHEAD FOR BULK OF PCPN TO BE RAIN BUT
AS COLDER AIR DEEPENS MON NGT IN WAKE OF FRONTAL PASSAGE COULD SEE
MIX OR BRIEF CHG TO -SN. TUE-WED LOOK TO BE MAINLY DRY AND COLDER.
..05..
.CLIMATE...
RECORD HIGHS FOR JANUARY 11...
RECORD HIGHS WERE TIED OR BROKEN TODAY
MOLINE.........56 IN 1880
CEDAR RAPIDS...51 IN 2002 AND OTHER YEARS
DUBUQUE........50 IN 1980
BURLINGTON.....55 IN 1980
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR CLINTON-JACKSON-SCOTT.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR BENTON-BUCHANAN-CEDAR-DELAWARE-DES
MOINES-DUBUQUE-HENRY IA-IOWA-JEFFERSON-JOHNSON-JONES-KEOKUK-
LEE-LINN-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
IL...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR BUREAU-CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-
MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-
WHITESIDE.
MO...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
555 PM CST WED JAN 11 2012
.UPDATE...
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
STRONG SUBSIDENCE WILL PERSIST THIS EVENING AS THE CONFLUENT REGION
OF THE UPPER LEVEL JET MOVES ACROSS THE AREA JUXTAPOSED WITH THE
DEEP NORTHWEST FLOW THROUGH THE BOUNDARY LAYER AND MIDDLE
TROPOSPHERE. LOCAL AWIPS GFS MOS AND MODELS INDICATE SURFACE WINDS
DECREASING OVER THE NEXT SEVERAL HOURS. HOWEVER, WITH THE GRADIENT
THAT IS IN PLACE, WINDS WILL AT LEAST REMAIN BREEZY WITH SPEEDS OF
15 TO 18 KNOTS WITH GUSTS TO THE LOW 20S THROUGH THE OVERNIGHT.
WINDS WILL INCREASE AGAIN IN THE DAY THURSDAY AS MIXING BECOMES A
FACTOR.
&&
.PREV DISCUSSION... /ISSUED 203 PM CST WED JAN 11 2012/
SYNOPSIS...
12Z RAOB PLOT ANALYSIS INDICATES A LARGE TROUGH PUSHING ACROSS THE ROCKIES
AND INTO THE NORTHERN PLAINS. THIS FEATURE HAS USHERED IN A COLD FRONT
EARLY THIS MORNING ACROSS SOUTHWEST KANSAS. AS OF 18Z, THIS FRONT IS
STILL MOVING ACROSS OKLAHOMA. WINDS WERE STRONG BEHIND THE FRONT WITH
MANY OBSERVATION SITES ACROSS WESTERN KANSAS REPORTING WINDS AROUND
30 KT.
DISCUSSION...
DAYS 1-2...
TONIGHT:
SHORT TERM FOCUS IS WINDS. HAVE UPDATED THE WIND ADVISORY FOR THE ENTIRE
REGION AS AWOS SITES ACROSS FAR WESTERN KANSAS HAVE BEEN AT WIND ADVISORY
CRITERIA EARLIER. HRRR AND NAM SHOW THAT WINDS WILL QUICKLY TAPER TOWARDS
6 PM CST. SECOND SHORT TERM FOCUS IS IF WE WILL SEE PRECIPITATION. THE
NAM HAS VERY LIGHT QPF ACROSS CENTRAL KANSAS TONIGHT. HRRR ALSO INDICATES
LIGHT COMPOSITE REFLECTIVITY FORECAST SO HAVE PUT 20 POPS ACROSS THE
NORTHEAST/NORTH. ELSEWHERE, WILL KEEP AROUND 10 PERCENT WITH FLURRIES. THIS
ACTIVITY WILL DIMINISH THIS EVENING. OVERNIGHT LOWS WILL BE ON THE COLD
SIDE AS WINDS WEAKEN AND SKIES CLEAR. WINDS WILL NOT COMPLETELY CALM
SO DID NOT GET TOO CARRIED AWAY WITH LOWS.
THURSDAY/THURSDAY NIGHT:
ANOTHER WINDY DAY LOOKS LIKELY ACROSS SOUTHWEST KANSAS TOMORROW. THIS
IS IN ASSOCIATION WITH A TIGHT PRESSURE GRADIENT REMAINING OVER THE
AREA. HAVE INCREASED WINDS IN THE GRIDS IN THE 20 TO 30 MPH RANGE BUT
KEPT VALUES/GUSTS BELOW WIND ADVISORY CRITERIA. INSTEAD OF HAVING TWO
WIND ADVISORIES OUT, WHICH COULD BE CONFUSING...I WILL LET THE MID SHIFT
DECIDE IF WE NEED A WIND ADVISORY OR NOT. TOMORROWS HIGHS WILL BE IN
THE 30S DEG F. OVERNIGHT LOWS ARE EXPECTED TO BE IN THE TEENS DEG F.
FRIDAY:
KANSAS WILL BE IN NORTHWEST FLOW ALOFT WHICH FAVORS A DRY FORECAST.
WILL KEEP POPS AT ZERO FRIDAY. COULD SEE SOME DOWNSLOPE WESTERLY WINDS
FRIDAY SO HAVE WARMED HIGHS UP A BIT. 850 HPA TEMPERATURES WARM UP INTO
THE LOWER SINGLE POSITIVE DIGITS DEG C, SO WE COULD SEE SOME MIXING
TO 40S DEG F AT THE SURFACE.
DAYS 3-7...
THE MID TO UPPER-LEVEL FLOW WILL GRADUALLY TRANSITION FROM
NORTHWESTERLY TO WEST-SOUTHWESTERLY FROM FRIDAY NIGHT INTO SUNDAY.
THUS, SURFACE PRESSURES WILL FALL IN THE LEE OF THE ROCKIES ALONG
WITH SOME WEAK LOW-LEVEL DOWNSLOPE FLOW. HIGH TEMPERATURES WILL
MODIFY INTO THE MID 50S BY SATURDAY AND 55 TO 60 BY SUNDAY.
A SHORTWAVE TROUGH WILL PROGRESS IN MAINLY ZONAL FLOW ACROSS THE
CENTRAL AND NORTHERN PLAINS BY MONDAY AND MONDAY NIGHT. THIS WILL
BRING SOME COLDER AIR INTO WESTERN KANSAS. SO AFTER A FAIRLY MILD
DAY MONDAY (50S TO LOWER 60S) JUST IN ADVANCE OF THE FRONT, HIGHS
WILL FALL INTO THE 30S OR LOWER 40S BY TUESDAY. NO PRECIPITATION CAN
BE EXPECTED IN THIS ZONAL PATTERN.
ANOTHER WARMING TREND IS EXPECTED BY JANUARY 18-19TH WITH HIGHS
POSSIBLY REACHING TO NEAR 70F IN A GENERALLY ZONAL MID TO UPPER-LEVEL
FLOW REGIME WITH LEE-TROUGHING AT LOW-LEVELS. HOWEVER, AS IS OFTEN
THE CASE IN ZONAL REGIMES, THERE WILL BE A SHARP TEMPERATURE
GRADIENT BETWEEN DOWNSLOPE FLOW OVER THE SOUTHERN AND CENTRAL PLAINS
AND ARCTIC AIR OVER THE NORTHERN PLAINS OR SOUTHERN CANADA. ANY
SHORTWAVE TROUGH TRAVERSING THE FLOW COULD RESULT IN ANOTHER SURGE
OF COLD AIR. THE ECMWF IS ADVERTISING ANOTHER SUCH COOLDOWN BY
JANUARY 20-21ST. NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH
JANUARY 21ST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 12 35 14 46 / 10 0 0 0
GCK 11 35 12 47 / 10 0 0 0
EHA 11 37 15 48 / 10 0 0 0
LBL 11 36 15 48 / 10 0 0 0
HYS 11 33 11 46 / 10 0 0 0
P28 17 37 15 46 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR KSZ030-
031-043>046-061>066-074>081-084>090.
&&
$$
FN99/99
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
410 PM EST TUE JAN 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY AND MILD CONDITIONS TONIGHT.
A LOW PRESSURE SYSTEM WILL THEN MOVE INTO THE AREA FROM THE
SOUTHWEST, BRINGING RAIN TO THE UPPER OHIO VALLEY WEDNESDAY AND
WEDNESDAY NIGHT. SNOW SHOWERS AND MORE SEASONABLE TEMPERATURES ARE
EXPECTED AFTER THE COLD FRONT PASSAGE LATE ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A DRY WEST-NORTHWESTERLY FLOW. AT THE SURFACE, A 1018MB HIGH IS
CENTERED ACROSS WEST VIRGINIA. THIS FEATURE ALONG WITH A DEEP
LAYER OF DRY AIR ALOFT ARE ALLOWING FOR SUNNY SKIES ACROSS MUCH OF
THE AREA.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS THE UPPER OHIO VALLEY
AND ALLOW CLEAR SKIES. CLOUD COVERAGE WILL BEGIN TO INCREASE FROM
THE SOUTHWEST TONIGHT AS CIRRUS SPILLS INTO THE AREA AHEAD OF THE
LOW ACROSS THE GULF STATES. RADIATIONAL COOLING INITIALLY TONIGHT
WILL BE COUNTERED BY THE INCREASING CLOUD COVERAGE AND WARM AIR
ADVECTION CLOSER TO DAWN ON WEDNESDAY. LOWS ARE FAIRLY CLOSE TO
MAV GUIDANCE, RANGING FROM THE UPPER 20S ALONG THE I-80 CORRIDOR
TO THE LOWER 30S ELSEWHERE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THERE IS REASONABLE MODEL AGREEMENT THAT A 500MB CLOSED LOW WILL
MOVE FROM THE TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES
WEDNESDAY AND WEDNESDAY NIGHT THEN INTO NEW ENGLAND ON THURSDAY.
FORECAST IS CLOSEST TO A SREF/NMM-WRF/NAM4KM BLEND WITH THE CHC POPS
BEGINNING JUST AFTER 12Z FOR AREAS ALONG AND SOUTH OF THE MASON-
DIXON LINE.
THE CHALLENGE WITH THE FORECAST WILL BE HOW THE TIMING OF INITIAL
PRECIP ALIGNS WITH NEAR FREEZING TEMPS ACROSS GARRETT AND TUCKER
COUNTIES. NAM/GFS MODEL SOUNDINGS ARE SUPPORTING A FREEZING RAIN
SOUNDING WITH 3-5C WARM NOSE. THE UNCERTAINTY IS HOW FAST SURFACE
TEMPS WILL WARM. HAVE ONLY HELD ONTO A -FZRA INTO THE LATE MORNING
FOR THESE AREAS. THIS IS MENTIONED IN THE HWO WITH AROUND A TRACE
TO A FEW HUNDREDTHS OF ICE ACCUMULATION FORECASTED. AN ADVISORY
MAY BE NEEDED FOR THESE AREAS, ALTHOUGH AT THIS TIME CONFIDENCE IS
TOO LOW. OTHERWISE, WARM WEDGE OF 850MB TEMPS WARMING TO 5-6C BY
WEDNESDAY AFTERNOON ACROSS THE AREA WILL ALLOW FOR PRECIPITATION
TO BE ALL IN THE FORM OF RAIN. FOR QPF, AMOUNTS ON WEDNESDAY WILL
RANGE FROM AROUND A QUARTER OF AN INCH NORTHWEST OF PITTSBURGH TO
THREE QUARTERS OF AN INCH TO AN INCH ACROSS THE RIDGES OF PA AND
MD. WARM AIR ADVECTION THROUGHOUT THE DAY WILL ALLOW FOR TEMPS TO
WARM TO AROUND 10 DEGREES ABOVE NORMALS. HIGHS WILL RANGE FROM THE
UPPER 30S ACROSS THE EASTERN RIDGES TO NEAR 50 FOR PORTIONS OF
EASTERN OHIO AND NORTH-CENTRAL WV.
WEDNESDAY NIGHT INTO THURSDAY...NAM/ECMWF/CANADIAN ARE INDICATING
THE SURFACE LOW SPLITTING INTO A DOUBLE BARREL LOW AS IT PUSHES INTO
THE NORTHEAST. SYNOPTIC FORCING WILL SHIFT NORTHEAST OF THE AREA WITH
THE LOWS AND THE UPPER OHIO VALLEY WILL BE IN THE WARM SECTOR.
THUS, THE FORECAST IS FOR LIKELY POPS WEDNESDAY NIGHT DECREASING
TO CHANCE ON THURSDAY. A COLD FRONT ASSOCIATED WITH THE WESTERN OF
THE TWO LOWS WILL SWING ACROSS THE OHIO VALLEY ON THURSDAY AND
BEGIN TO MOVE INTO EASTERN OHIO LATE IN THE DAY. THIS WILL ALLOW
FOR ANY PRECIP TO CHANGE TO SNOW BEHIND THE FRONT. WITH THE WARM
AIR MASS STILL IN PLACE, TEMPS WILL REMAIN 10-15 DEGREES ABOVE
NORMAL.
THURSDAY NIGHT INTO FRIDAY...GFS IS FASTER THAN THE NAM WITH COLD
AIR ADVECTION AND CHANGE OVER OF PRECIP FROM RAIN TO SNOW. FORECAST IS
A BLEND OF THE TWO, PUSHING 1000-500MB 5400M THICKNESS LINE EAST OF
THE AREA AFTER 00Z AND CHANGING RAIN SHOWERS OVER TO SNOW SHOWERS
ACROSS THE AREA BY MIDNIGHT. THE INITIAL LOW THAT SHIFTED NORTHWEST
OF THE AREA WILL THEN MERGE INTO A NORTHERN STREAM UPPER LEVEL LOW
THAT WILL PUSH FROM THE GREAT LAKES INTO THE EASTERN CANADA ON
FRIDAY. THIS WILL ALLOW FOR CONTINUED STRONG COLD AIR ADVECTION.
WITH THIS FEATURE NORTH OF THE AREA, LOW-LEVEL FLOW WILL BE
WEST-SOUTHWESTERLY. COLD AIR ADVECTION SHOULD INSTIGATE SNOW
SHOWERS, ALTHOUGH EXPECT LITTLE ACCUMULATION ACROSS THE LOWLANDS.
SOME UPSLOPING WILL OCCUR ACROSS THE RIDGES THAT WOULD ALLOW FOR
ONE TO TWO INCHES OF SNOW ACCUMULATION ACROSS THERE. TEMPS WILL
BE NOTICEABLY COLDER, RANGING FROM THE UPPER TEENS ACROSS THE
EASTERN RIDGES TO THE LOWER 20S ELSEWHERE. TEMPS WILL ONLY
INCREASE A FEW DEGREES THROUGH THE DAY ON FRIDAY WITH HIGH RANGING
FROM THE LOWER 20S ACROSS THE EASTERN RIDGES TO THE MID 20S ACROSS
THE LOWLANDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LATEST ECMWF AND GFS RUNS APPEAR TO BE IN SOMEWHAT BETTER AGREEMENT
THAN IN EARLIER RUNS...SHOWING CLOSED UPPER LOW DEPARTING NEW
ENGLAND SATURDAY AND ANOTHER SHORT WAVE TROUGH CROSSING THE GREAT
LAKES REGION SATURDAY NIGHT. EXPECT COVERAGE OF SNOW SHOWERS TO
DECREASE SATURDAY...WITH CLOUD COVER ASSOCIATED WITH SECOND UPPER
TROUGH REMAINING OVER THE REGION INTO EARLY SUNDAY.
A BUILDING SURFACE RIDGE IS EXPECTED TO PROVIDE A PERIOD OF DRY
WEATHER SUNDAY AND MONDAY...WITH TEMPERATURES MODERATING FROM BELOW
NORMAL SATURDAY TO AROUND 10 DEGREES ABOVE THE NORM MONDAY.
THE NEXT APPROACHING SYSTEM WILL PUSH A COLD FRONT TOWARD THE UPPER
OHIO VALLEY TUESDAY. TEMPERATURES SHOULD REMAIN WARM ENOUGH FOR MOST
ASSOCIATED PRECIPITATION TO FALL IN THE FORM OF RAIN TUESDAY.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
SCATTERED DIURNAL CUMULUS HAVE DEVELOPED MAINLY NORTH OF A KPIT-KLBE
LINE. EXPECT THESE CLOUDS TO DISSIPATE AROUND SUNSET. WEST SURFACE
WINDS AROUND 10KT WILL BECOME LIGHT SOUTHEAST OVERNIGHT.
CONDITIONS ARE EXPECTED TO LOWER TO MVFR DURING WEDNESDAY AFTERNOON
AS RAIN SPREADS NORTHEAST AHEAD OF APPROACHING LOW PRESSURE SYSTEM
MOVING NORTHEAST FROM THE GULF STATES.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
MVFR AND AREAS OF IFR CAN BE EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY
AS THE LOW MOVES NORTHEAST ACROSS THE REGION. COLDER AIR WILL PUSH
IN BEHIND THE SYSTEM BEGINNING THURSDAY NIGHT...AND PRECIPITATION
WILL CHANGE OVER TO SNOW. SCATTERED SNOW SHOWERS AND THE POTENTIAL
FOR RESTRICTIONS WILL CONTINUE THROUGH FRIDAY NIGHT.
WEAK RIDGING SHOULD PROVIDE IMPROVEMENT TO VFR BY SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
136 PM EST TUE JAN 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY AND MILD CONDITIONS THIS AFTERNOON
AND TONIGHT BEFORE A LOW PRESSURE SYSTEM MOVES NORTHEASTWARD,
BRINGING RAIN TO THE UPPER OHIO VALLEY WEDNESDAY AND WEDNESDAY
NIGHT. SNOW SHOWERS AND MORE SEASONABLE TEMPERATURES ARE EXPECTED
AFTER THE COLD FRONT PASSAGE LATE ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN MADE TO ADJUST
SKY GRIDS NORTHEAST OF PITTSBURGH WITH SCATTERED DIURNAL CUMULUS
DEVELOPING. OTHERWISE, NO CHANGES TO GOING FORECAST.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A DRY WEST-NORTHWESTERLY FLOW. THUS, THERE HAS BEEN ENOUGH
MOISTURE OFF OF LAKE ERIE TO ALLOW FOR SOME DIURNAL CUMULUS TO
DEVELOP NORTHEAST OF PITTSBURGH IN THIS FLOW REGIME. AT THE
SURFACE, A 1019MB HIGH IS CENTERED ACROSS WEST VIRGINIA. THIS
FEATURE ALONG WITH A DEEP LAYER OF DRY AIR ALOFT ARE ALLOWING
FOR SUNNY SKIES ACROSS MUCH OF THE AREA.
THIS AFTERNOON AND TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS THE
UPPER OHIO VALLEY AND ALLOW SUNNY SKIES TODAY. WITH WEAK WARM AIR
ADVECTION AND ABUNDANT SUNSHINE, HIGHS TODAY ARE GENERALLY 1-2 DEGREES
ABOVE A MAV/MET BLEND, RANGING FROM THE LOWER 40S ACROSS THE I-80
CORRIDOR TO THE LOWER 50S IN PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL
WV. CLOUD COVERAGE WILL BEGIN TO INCREASE FROM THE SOUTHWEST
TONIGHT AS CIRRUS SPILLS INTO THE AREA AHEAD OF THE LOW ACROSS THE
GULF STATES. RADIATIONAL COOLING INITIALLY TONIGHT WILL BE COUNTERED
BY THE INCREASING CLOUD COVERAGE AND WARM AIR ADVECTION CLOSER TO
DAWN ON WEDNESDAY. LOWS ARE FAIRLY CLOSE TO MAV GUIDANCE, RANGING
FROM THE UPPER 20S ALONG THE I-80 CORRIDOR TO THE LOWER 30S
ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
THE AREA SHOULD REMAIN DRY EARLY WEDNESDAY AS THE LOW PRESSURE
SYSTEM MAKES ITS WAY NORTHWARD FROM LOUISIANA. ADJUSTED POP
TIMING JUST SLIGHTLY, BRINGING LIKELY POPS IN A BIT EARLIER AS
DETERMINISTIC MODELS AND SREF MEAN ARE LINING UP RELATIVELY WELL
FOR THE FIRST HALF OF THE PERIOD. GENERAL CONSENSUS IS THAT
PRECIPITATION WILL BEGIN FALLING AS RAIN AS MODEL PROFILES SUGGEST
THICKNESS VALUES WILL BE WELL WARM ENOUGH FOR RAIN DESPITE THE MID
30 TEMPERATURES AT THE SURFACE WEDNESDAY MORNING. THE ONLY CONCERN
FOR ANY FREEZING RAIN MAY COME IN SOME OF THE SHELTERED VALLEY
LOCATIONS IN THE EASTERN RIDGES EARLY WEDNESDAY, BUT IT WOULD BE
BRIEF. THIS MENTION HAS BEEN ADDED TO THE HWO.
WEDNESDAY NIGHT ANOTHER UPPER LEVEL WAVE DROPPING SOUTH OUT OF THE
NORTHERN PLAINS WILL HELP TO PUSH THE SYSTEM OVER WESTERN PA
TOWARDS THE COAST, AND ALLOW FOR THE PASSAGE OF THE LAGGING COLD
FRONT. IN ADDITION, THIS SECONDARY SYSTEM WILL BRING THE
REINFORCING SHOT OF COLD AIR NEEDED TO TRANSITION RAIN SHOWERS TO
SNOW SHOWERS LATE THURSDAY.
INFLOW OF WARMER AIR AHEAD OF THE LOW PRESSURE AND COLD FRONT WILL
MAINTAIN TEMPERATURES CLOSE TO 10 DEGREES WARMER THAN NORMAL THROUGH
THE PERIOD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
CONSENSUS OF ECMWF AND NAEFS MODEL OUTPUT SHOWS A COLD, CLOSED
UPPER LEVEL LOW PASSING EASTWARD THROUGH THE GREAT LAKES FRIDAY.
THIS WILL INDUCE A COLD WESTERLY LOW LEVEL FLOW ACROSS THE UPPER
OHIO VALLEY FOR FRIDAY INTO SATURDAY. AT THIS JUNCTURE, DOWN-LAKE
TRAJECTORIES ARE NOT ALL THAT FAVORABLE FOR A WIDESPREAD LAKE-
EFFECT SNOW SHOWER EVENT, BUT SHOULD FLOW SHOULD PROVIDE ENOUGH
MOISTURE AND INSTABILITY TO PROMOTE SCATTERED SNOW SHOWERS, AND
PERHAPS NUMEROUS SNOW SHOWERS AT TIMES ACROSS NORTHWESTERN PA AND
THE HIGHER MOUNTAINS.
FORECASTED TEMPERATURES, USING BLEND OF GFS MOS AND NAEFS MEDIAN
VALUES, TO BE NOTICEABLY COLDER THAN PREVIOUS DAYS, WITH
TEMPERATURES ABOUT 5 DEGREES COLDER THAN NORMAL FRIDAY AND
SATURDAY. TEMPERATURES MAY RECOVER TO NEAR NORMAL VALUES SUNDAY
AND MONDAY.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
VFR WILL PREDOMINATE IN THE DRY AIRMASS OVER THE UPPER OH VALLEY
REGION. SURFACE WINDS AROUND 10KT WILL BECOME WESTERLY WITH THE
PASSAGE OF A SURFACE TROUGH.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
LOW PRESSURE MOVING OUT OF THE SOUTHERN U.S. WILL SPREAD RA AND
RESTRICTIONS OVER THE UPPER OH REGION FOR LATE WEDNESDAY AND
THURSDAY. COLD ADVECTION IN THE WAKE OF THAT SYSTEM WILL SUPPORT
RESTRICTIONS AND SHSN POTENTIAL FOR THE REMAINDER OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1127 AM EST TUE JAN 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY AND MILD CONDITIONS THIS AFTERNOON
AND TONIGHT BEFORE A LOW PRESSURE SYSTEM MOVES NORTHEASTWARD,
BRINGING RAIN TO THE UPPER OHIO VALLEY WEDNESDAY AND WEDNESDAY
NIGHT. SNOW SHOWERS AND MORE SEASONABLE TEMPERATURES ARE EXPECTED
AFTER THE COLD FRONT PASSAGE THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATE MORNING ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED
TO MAKE ADJUSTMENTS TO INCREASE TEMPS A FEW DEGREES TODAY AND TO
ADD A FEW HOURS OF FREEZING RAIN EARLY ON WEDNESDAY FOR TUCKER AND
GARRETT COUNTIES.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A DRY WEST-NORTHWESTERLY FLOW. CLOUD COVERAGE NORTHEAST OF
PITTSBURGH ASSOCIATED WITH THIS FLOW REGIME IS DIMINISHING. AT THE
SURFACE, A 1021MB HIGH IS CENTERED ACROSS EASTERN KENTUCKY. THIS
FEATURE ALONG WITH A DEEP LAYER OF DRY AIR ALOFT ARE ALLOWING FOR
SUNNY SKIES ACROSS MUCH OF THE AREA.
THIS AFTERNOON AND TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS THE
UPPER OHIO VALLEY AND ALLOW SUNNY SKIES TODAY. WITH WEAK WARM AIR
ADVECTION AND ABUNDANT SUNSHINE, HIGHS TODAY ARE GENERALLY 1-2 DEGREES
ABOVE A MAV/MET BLEND, RANGING FROM THE LOWER 40S ACROSS THE I-80
CORRIDOR TO THE LOWER 50S IN PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL
WV. CLOUD COVERAGE WILL BEGIN TO INCREASE FROM THE SOUTHWEST
TONIGHT AS CIRRUS SPILLS INTO THE AREA AHEAD OF THE LOW ACROSS THE
GULF STATES. RADIATIONAL COOLING INITIALLY TONIGHT WILL BE COUNTERED
BY THE INCREASING CLOUD COVERAGE AND WARM AIR ADVECTION CLOSER TO
DAWN ON WEDNESDAY. LOWS ARE FAIRLY CLOSE TO MAV GUIDANCE, RANGING
FROM THE UPPER 20S ALONG THE I-80 CORRIDOR TO THE LOWER 30S
ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
THE AREA SHOULD REMAIN DRY EARLY WEDNESDAY AS THE LOW PRESSURE
SYSTEM MAKES ITS WAY NORTHWARD FROM LOUISIANA. ADJUSTED POP
TIMING JUST SLIGHTLY, BRINGING LIKELY POPS IN A BIT EARLIER AS
DETERMINISTIC MODELS AND SREF MEAN ARE LINING UP RELATIVELY WELL
FOR THE FIRST HALF OF THE PERIOD. GENERAL CONSENSUS IS THAT
PRECIPITATION WILL BEGIN FALLING AS RAIN AS MODEL PROFILES SUGGEST
THICKNESS VALUES WILL BE WELL WARM ENOUGH FOR RAIN DESPITE THE MID
30 TEMPERATURES AT THE SURFACE WEDNESDAY MORNING. THE ONLY CONCERN
FOR ANY FREEZING RAIN MAY COME IN SOME OF THE SHELTERED VALLEY
LOCATIONS IN THE EASTERN RIDGES EARLY WEDNESDAY, BUT IT WOULD BE
BRIEF. THIS MENTION HAS BEEN ADDED TO THE HWO.
WEDNESDAY NIGHT ANOTHER UPPER LEVEL WAVE DROPPING SOUTH OUT OF THE
NORTHERN PLAINS WILL HELP TO PUSH THE SYSTEM OVER WESTERN PA
TOWARDS THE COAST, AND ALLOW FOR THE PASSAGE OF THE LAGGING COLD
FRONT. IN ADDITION, THIS SECONDARY SYSTEM WILL BRING THE
REINFORCING SHOT OF COLD AIR NEEDED TO TRANSITION RAIN SHOWERS TO
SNOW SHOWERS LATE THURSDAY.
INFLOW OF WARMER AIR AHEAD OF THE LOW PRESSURE AND COLD FRONT WILL
MAINTAIN TEMPERATURES CLOSE TO 10 DEGREES WARMER THAN NORMAL THROUGH
THE PERIOD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
CONSENSUS OF ECMWF AND NAEFS MODEL OUTPUT SHOWS A COLD, CLOSED
UPPER LEVEL LOW PASSING EASTWARD THROUGH THE GREAT LAKES FRIDAY.
THIS WILL INDUCE A COLD WESTERLY LOW LEVEL FLOW ACROSS THE UPPER
OHIO VALLEY FOR FRIDAY INTO SATURDAY. AT THIS JUNCTURE, DOWN-LAKE
TRAJECTORIES ARE NOT ALL THAT FAVORABLE FOR A WIDESPREAD LAKE-
EFFECT SNOW SHOWER EVENT, BUT SHOULD FLOW SHOULD PROVIDE ENOUGH
MOISTURE AND INSTABILITY TO PROMOTE SCATTERED SNOW SHOWERS, AND
PERHAPS NUMEROUS SNOW SHOWERS AT TIMES ACROSS NORTHWESTERN PA AND
THE HIGHER MOUNTAINS.
FORECASTED TEMPERATURES, USING BLEND OF GFS MOS AND NAEFS MEDIAN
VALUES, TO BE NOTICEABLY COLDER THAN PREVIOUS DAYS, WITH
TEMPERATURES ABOUT 5 DEGREES COLDER THAN NORMAL FRIDAY AND
SATURDAY. TEMPERATURES MAY RECOVER TO NEAR NORMAL VALUES SUNDAY
AND MONDAY.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
VFR WILL PREDOMINATE IN THE DRY AIRMASS OVER THE UPPER OH VALLEY
REGION. SURFACE WINDS AROUND 10KT WILL BECOME WESTERLY WITH THE
PASSAGE OF A SURFACE TROUGH.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
LOW PRESSURE MOVING OUT OF THE SOUTHERN U.S. WILL SPREAD RA AND
RESTRICTIONS OVER THE UPPER OH REGION FOR LATE WEDNESDAY AND
THURSDAY. COLD ADVECTION IN THE WAKE OF THAT SYSTEM WILL SUPPORT
RESTRICTIONS AND SHSN POTENTIAL FOR THE REMAINDER OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
642 AM EST TUE JAN 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY. LOW PRESSURE WILL
TRACK INTO EAST TENNESSEE TUESDAY NIGHT BEFORE AFFECTING THE MID-
ATLANTIC REGION WEDNESDAY AND WEDNESDAY NIGHT. A COLD FRONT IS
EXPECTED TO CROSS THE REGION THURSDAY...USHERING IN MUCH COLDER
AIR FOR THE REGION.
&&
.NEAR TERM /TODAY/...
IT`S BEEN A VERY BUSY NGT. DENSE FOG ADVSRY WAS ISSUED AT 520
AM BTWN 1-95 AND I-81 THRU 9 AM...BUT NOW VSBYS ARE IMPRVG AS WRLY
WINDS MOVE E OF THE MTNS. PLAN WL BE TO LV ADSRY IN EFFECT BUT LET
ONCOMING DAYSHIFT REEVALUATE AND CANX EARLY IF CONDTIONS WARRANT.
**
(444 AM DSCN)
AS WRITTEN EARLIER - FOG/LOW CLDS ARE THE MAIN CONCERN OF THE
OVRNGT HRS. AS QUITE A FEW AVIATION OBS ARE COMING IN BLO 1/2 MI
W OF I-95 TO I-81 I`VE BEEN SCANNING THE TRAFFIC CAMS...AND THERE
IS A WIDE VARIANCE IN VSBYS - FM 1/2 MI IN FOG TO CRYSTAL CLR. WE
HV REISSUED AN SPS FOR PATCHY DENSE FOG ALONG W/ PTNL FOR ICY
SPOTS ON BRIDGES/OVRPASSES GIVEN AIR TEMPS HOVERING ARND THE FRZG
MARK. WE`LL RMN VIGILANT OVR THE NEXT FEW HRS...AND ISSUE A DENSE
FOG ADVSRY IF NEEDED B4 THE BULK OF COMMUTERS TAKE TO THE ROADS.
AS OF NOW - IF THAT HAPPENS AN ADVSRY WOULD NOT INCLUDE THE
495/95/695 CORRIDOR.
PRVS DSCN (326 AM)...
ATTM WE ARE KEEPING OUR EYES ON FOG AND LOW CLD. ON IR STLT IT IS
NOT IMMEDIATELY CLR WHERE THE CLDS ARE - BEST TO USE 11-3.9 MU
OVERLAIN W/ CIG/VSBY...AS WELL AS GO OUT AND LOOK AT THE SKY (AT
LEAST LOCALLY). BUT IT DOES APPEAR THAT DRIER AIR IS MOVG INTO THE
AREA AS W OF THE BLUE RDG NOT REPORTING ANY CLDS WHILE E OF THE
MTNS ARE SOCKED IN W/ OVC SKIES. IN A WAY THAT IS A BLESSING AS
THE LOW CLDS ARE PREVENTING THE RAD CONDS THAT COULD FACILITATE
DENSE FOG - E OF MTNS VSBYS GNRLY IN 2-4 MI RANGE ATTM WITH A FEW
OUTLIERS AT EITHER END OF THE SPECTRUM.
THERE WAS SOME WETNESS OVR MUCH OF THE CWA MON...AND THERE`LL BE
MORE ON WED...BUT TDA SHOULD BE DRY AS HIGH PRES MOVES INTO THE
AREA. WRLY WINDS WL BE DOWNSLOPING..AND IT SHOULDN`T BE LONG THIS
MRNG B4 THE SNOW THAT FELL MON IS GONE. TEMPS SHOULD TOP OUT IN
THE U40S/L50S W/ XCPTN OF M40S IN THE HIGHLANDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THE EVE HRS SHOULD GNRLY BE CLR..ALLOWING TEMPS TO DROP THRU THE
40S FAIRLY QUICKLY. CLDS WL BEGIN TO INCRS AFTR MDNGT IN HIGHLAND/
PENDLETON AS THE NEXT SHORT WV TRACKS ACROSS THE GULF STATES.
BECAUSE OF THE INCRSG CLDS TEMPS WON`T GET QUITE AS COLD IN THE
CENTRAL SHEN VLLY AS THEY WL NEAR THE MASON-DIXON LN. TEMPS WL
RANGE FM THE MU20S N TO M30S S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A COUPLE OF VERY DIFFERENT BUT COMPLEX LOW PRESSURE SYSTEMS WILL
MERGE JUST NORTH OF THE AREA MID WEEK. BEFORE THEN...AND OVER THE
NEXT 2 DAYS - THESE WILL BE MAKING THEIR WAY TO THE MID ATLC /ONE
FROM THE NRN PLAINS AND ONE FROM THE SRN PLAINS/. THE SRN PLAINS
SYSTEM WILL BRING STEADY RAINS TO THE AREA ON WED-EARLY
THU...ARRIVING JUST AHEAD OF THE DRIER AND COLDER NRN PLAINS
SYSTEM. BOTH CLOSED UPPER LOWS WILL STRENGTHEN OVER THE NEXT 24-36
HRS AS THEY APPROACH OUR AREA. THE SRN PLAINS LOW THAT HAS ALREADY
SPREAD MODERATE TO HEAVY RAINFALL FROM TX/OK TO THE MISSISSIPPI
VLY WILL CONTINUE TO DEEPEN AS IT MOVES DUE EAST TODAY.
BY EARLY WED...THE NRN PLAINS LOW WILL QUICKLY DROP SWD AND PUSH THE
SRN PLAINS LOW RIGHT UP THE ERN SEABOARD ONCE IT REACHES THE APLCNS.
BEFORE THEN...THE LOW WILL HAVE TAPPED INTO A BETTER GULF MOISTURE
FETCH AS BEGIN TO PULL THAT LOW LEVEL MOISTURE UP ACROSS THE
CAROLINAS AND THE LEE SIDE OF THE BLUE RIDGE. DRIER WLY WINDS FROM
TODAY AND TONIGHT WILL KEEP THE LOW LEVEL CONDITIONS FAVORABLE FOR A
RAIN-SNOW MIX AT ONSET OF PRECIP AFTER DAWN ON WED. AS THE SFC LOW
STRENGTHENS AND DRIFTS UP THE I-95 CORRIDOR...RELATIVELY WARMER AND
MORE MOIST ELY ONSHORE FLOW WILL HELP TEMPER THESE LOW LEVEL
CONDITIONS AND MAKE FOR MORE OF A COLD RAIN HEADING INTO THE AFTN
HRS. STEADY BATCHES OF RAIN WILL MOVE OVER THE REGION LATER IN THE
DAY AND ESPECIALLY FOR THE LATE NIGHT HRS. AVG MODEL QPFS RANGE IN
THE 0.50-1.00 INCH RANGE W/ LOCALLY HIGHER AMNTS ALONG AND E OF
I-95. MUCH OF THIS WILL BE STRETCHED OUT OVER A BETTER PART OF THE
DAY/EVE.
THE NRN PLAINS UPPER LOW WILL THEN KICK OUT THIS SYSTEM QUICKLY UP
ACROSS THE SRN NEW ENGLAND COAST. BY EARLY THU...PRECIP WILL BE
DISSIPATING OVER THE PIEDMONT BUT ANOTHER COLD SURGE WILL BE RIGHT
ON ITS HEELS. AS THE NEW ENGLAND SYSTEM RACES OFF THE COAST...THE
GREAT LAKES UPPER LOW WILL HAVE A COUPLE MORE DAYS TO SLOWLY ROTATE
EWD. COLDER AND DRIER CANADIAN AIR WILL BE ON THE WAY...THOUGH NOT
AS COLD AS OUR RECENT BOUT. CONDITIONS TO CLOSE OUT THE WEEK WILL BE
BLUSTERY AND COLD...W/ A RETURN TO THE DRIER AIR OF DEWPOINTS IN THE
SINGLE DIGITS AND TEENS AGAIN. THIS SYSTEM WILL MAKE AN EXIT OFF THE
COAST ON SAT...BUT ANOTHER REINFORCING SHOT OF COLD-DRY AIR WILL
COME IN FROM BEHIND ON SUN. A GRADUAL RETURN TO MORE MILD CONDITIONS
/THOUGH STILL MAINLY DRY/ FOR EARLY NEXT WEEK.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
LOW VSBYS IN FOG AT THE SITES OUTSIDE OF THE MAJOR CITIES. THESE
ARE XPCTD TO IMPROVE THIS MRNG AS HIGH BUILDS INTO THE MID ATLC.
ATTM IAD...CHO...MRB ALL XPRNCG VSBYS UNDER 1SM. RUC BUFKIT
TEMP/DWPT PROFILES SHOW LOW LVL MOISTURE COLUMN THINNING 1ST AT
MRB ARND SUNRISE...THEN E OF THE MTNS BTWN 8 AND 9 AM. VFR CONDS
XPCTD AT ALL SITES THEREAFTER THROUGH THE DAYLGT HRS AND TNGT.
HIGH CLDS WL BEGIN TO OVRSPREAD FM THE SW AFTR MDNGT.
A LOW PRESSURE SYSTEM WILL QUICKLY SLIDE UP ACROSS THE AREA FROM THE
SW...FROM LATE MRNG WED THROUGH MIDDAY THU. MAINLY PERIODS OF RAIN
W/ BREEZY LOW LEVEL WINDS CLOSER TO THE MD BAY/DELMARVA. THE LOW
WILL MOVE NE ON THU...W/ A COUPLE OF BREEZY AND DRY UPPER LEVEL
SYSTEMS READY TO MOVE DOWN ACROSS THE REGION TO END THE WEEK. HIGH
PRESSURE WILL BEGIN IN FOR THE EARLY PART OF NEXT WEEK.
&&
.MARINE...
HV REISSUED THE SML CRFT ADVSRY TO INCLUDE ALL OF THE WATERS FOR
THE AFTN HRS. HIGH PRES BLDG INTO THE WATERS WL CAUSE A PD OF
15-20 KT WINDS. NO PROBS THIS MRNG OR TNGT.
A LOW PRESSURE SYSTEM WILL MOVE TOWARD THE AREA TODAY AND EARLY WED.
SCA CONDITIONS EXPECTED OVERNIGHT WED NIGHT INTO EARLY THU...AS A
STRENGTHENING SFC LOW DRIFTS UP THE I-95 CORRIDOR TOWARD THE LOWER
MD BAY/TP. THIS RAINY SYSTEM WILL RACE TOWARD NEW ENGLAND EARLY
THU...WHILE A COUPLE OF DRY AND BREEZY UPPER WAVES GEAR UP TO SWING
OVER THE AREA. THESE UPPER LEVEL FEATURES WILL BRING SCA CONDITIONS
TO THE AREA TO END THE WEEK.
&&
.TIDES/COASTAL FLOODING...
LOW PRESSURE APPROACHES AREA WED...AND PASSES NE OF REGION EARLY
THU. THERE WL BE A PERIOD OF STRONG ELY FLOW WED NIGHT...WHEN
TIDAL DEPARTURES MAY INCREASE BY A FT OR MORE. WE`RE JUST PAST
FULL MOON...SO THERE WL BE A TIDAL CONTRIBUTION AS WELL. MAY GET
CLOSE TO MINOR THRESHOLDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR MDZ003>005-
009-010.
VA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ025>031-
036>040-042-050>053-501-502.
WV...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ052-053.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM EST THIS EVENING
FOR ANZ530>543.
SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 AM EST THURSDAY
FOR ANZ530>534-537>543.
&&
$$
PRODUCTS...WOODY!/GMS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
444 AM EST TUE JAN 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY. LOW PRESSURE WILL
TRACK INTO EAST TENNESSEE TUESDAY NIGHT BEFORE AFFECTING THE MID-
ATLANTIC REGION WEDNESDAY AND WEDNESDAY NIGHT. A COLD FRONT IS
EXPECTED TO CROSS THE REGION THURSDAY...USHERING IN MUCH COLDER
AIR FOR THE REGION.
&&
.NEAR TERM /TODAY/...
AS WRITTEN EARLIER - FOG/LOW CLDS ARE THE MAIN CONCERN OF THE
OVRNGT HRS. AS QUITE A FEW AVIATION OBS ARE COMING IN BLO 1/2 MI
W OF I-95 TO I-81 I`VE BEEN SCANNING THE TRAFFIC CAMS...AND THERE
IS A WIDE VARIANCE IN VSBYS - FM 1/2 MI IN FOG TO CRYSTAL CLR. WE
HV REISSUED AN SPS FOR PATCHY DENSE FOG ALONG W/ PTNL FOR ICY
SPOTS ON BRIDGES/OVRPASSES GIVEN AIR TEMPS HOVERING ARND THE FRZG
MARK. WE`LL RMN VIGILANT OVR THE NEXT FEW HRS...AND ISSUE A DENSE
FOG ADVSRY IF NEEDED B4 THE BULK OF COMMUTERS TAKE TO THE ROADS.
AS OF NOW - IF THAT HAPPENS AN ADVSRY WOULD NOT INCLUDE THE
495/95/695 CORRIDOR.
PRVS DSCN (326 AM)...
ATTM WE ARE KEEPING OUR EYES ON FOG AND LOW CLD. ON IR STLT IT IS
NOT IMMEDIATELY CLR WHERE THE CLDS ARE - BEST TO USE 11-3.9 MU
OVERLAIN W/ CIG/VSBY...AS WELL AS GO OUT AND LOOK AT THE SKY (AT
LEAST LOCALLY). BUT IT DOES APPEAR THAT DRIER AIR IS MOVG INTO THE
AREA AS W OF THE BLUE RDG NOT REPORTING ANY CLDS WHILE E OF THE
MTNS ARE SOCKED IN W/ OVC SKIES. IN A WAY THAT IS A BLESSING AS
THE LOW CLDS ARE PREVENTING THE RAD CONDS THAT COULD FACILITATE
DENSE FOG - E OF MTNS VSBYS GNRLY IN 2-4 MI RANGE ATTM WITH A FEW
OUTLIERS AT EITHER END OF THE SPECTRUM.
THERE WAS SOME WETNESS OVR MUCH OF THE CWA MON...AND THERE`LL BE
MORE ON WED...BUT TDA SHOULD BE DRY AS HIGH PRES MOVES INTO THE
AREA. WRLY WINDS WL BE DOWNSLOPING..AND IT SHOULDN`T BE LONG THIS
MRNG B4 THE SNOW THAT FELL MON IS GONE. TEMPS SHOULD TOP OUT IN
THE U40S/L50S W/ XCPTN OF M40S IN THE HIGHLANDS.
&&
.SHORT TERM /TONIGHT/...
THE EVE HRS SHOULD GNRLY BE CLR..ALLOWING TEMPS TO DROP THRU THE
40S FAIRLY QUICKLY. CLDS WL BEGIN TO INCRS AFTR MDNGT IN HIGHLAND/
PENDLETON AS THE NEXT SHORT WV TRACKS ACROSS THE GULF STATES.
BECAUSE OF THE INCRSG CLDS TEMPS WON`T GET QUITE AS COLD IN THE
CENTRAL SHEN VLLY AS THEY WL NEAR THE MASON-DIXON LN. TEMPS WL
RANGE FM THE MU20S N TO M30S S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A COUPLE OF VERY DIFFERENT BUT COMPLEX LOW PRESSURE SYSTEMS WILL
MERGE JUST NORTH OF THE AREA MID WEEK. BEFORE THEN...AND OVER THE
NEXT 2 DAYS - THESE WILL BE MAKING THEIR WAY TO THE MID ATLC /ONE
FROM THE NRN PLAINS AND ONE FROM THE SRN PLAINS/. THE SRN PLAINS
SYSTEM WILL BRING STEADY RAINS TO THE AREA ON WED-EARLY
THU...ARRIVING JUST AHEAD OF THE DRIER AND COLDER NRN PLAINS
SYSTEM. BOTH CLOSED UPPER LOWS WILL STRENGTHEN OVER THE NEXT 24-36
HRS AS THEY APPROACH OUR AREA. THE SRN PLAINS LOW THAT HAS ALREADY
SPREAD MODERATE TO HEAVY RAINFALL FROM TX/OK TO THE MISSISSIPPI
VLY WILL CONTINUE TO DEEPEN AS IT MOVES DUE EAST TODAY.
BY EARLY WED...THE NRN PLAINS LOW WILL QUICKLY DROP SWD AND PUSH THE
SRN PLAINS LOW RIGHT UP THE ERN SEABOARD ONCE IT REACHES THE APLCNS.
BEFORE THEN...THE LOW WILL HAVE TAPPED INTO A BETTER GULF MOISTURE
FETCH AS BEGIN TO PULL THAT LOW LEVEL MOISTURE UP ACROSS THE
CAROLINAS AND THE LEE SIDE OF THE BLUE RIDGE. DRIER WLY WINDS FROM
TODAY AND TONIGHT WILL KEEP THE LOW LEVEL CONDITIONS FAVORABLE FOR A
RAIN-SNOW MIX AT ONSET OF PRECIP AFTER DAWN ON WED. AS THE SFC LOW
STRENGTHENS AND DRIFTS UP THE I-95 CORRIDOR...RELATIVELY WARMER AND
MORE MOIST ELY ONSHORE FLOW WILL HELP TEMPER THESE LOW LEVEL
CONDITIONS AND MAKE FOR MORE OF A COLD RAIN HEADING INTO THE AFTN
HRS. STEADY BATCHES OF RAIN WILL MOVE OVER THE REGION LATER IN THE
DAY AND ESPECIALLY FOR THE LATE NIGHT HRS. AVG MODEL QPFS RANGE IN
THE 0.50-1.00 INCH RANGE W/ LOCALLY HIGHER AMNTS ALONG AND E OF
I-95. MUCH OF THIS WILL BE STRETCHED OUT OVER A BETTER PART OF THE
DAY/EVE.
THE NRN PLAINS UPPER LOW WILL THEN KICK OUT THIS SYSTEM QUICKLY UP
ACROSS THE SRN NEW ENGLAND COAST. BY EARLY THU...PRECIP WILL BE
DISSIPATING OVER THE PIEDMONT BUT ANOTHER COLD SURGE WILL BE RIGHT
ON ITS HEELS. AS THE NEW ENGLAND SYSTEM RACES OFF THE COAST...THE
GREAT LAKES UPPER LOW WILL HAVE A COUPLE MORE DAYS TO SLOWLY ROTATE
EWD. COLDER AND DRIER CANADIAN AIR WILL BE ON THE WAY...THOUGH NOT
AS COLD AS OUR RECENT BOUT. CONDITIONS TO CLOSE OUT THE WEEK WILL BE
BLUSTERY AND COLD...W/ A RETURN TO THE DRIER AIR OF DEWPOINTS IN THE
SINGLE DIGITS AND TEENS AGAIN. THIS SYSTEM WILL MAKE AN EXIT OFF THE
COAST ON SAT...BUT ANOTHER REINFORCING SHOT OF COLD-DRY AIR WILL
COME IN FROM BEHIND ON SUN. A GRADUAL RETURN TO MORE MILD CONDITIONS
/THOUGH STILL MAINLY DRY/ FOR EARLY NEXT WEEK.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
LOW VSBYS IN FOG AT THE SITES OUTSIDE OF THE MAJOR CITIES. THESE
ARE XPCTD TO IMPROVE THIS MRNG AS HIGH BUILDS INTO THE MID ATLC.
ATTM IAD...CHO...MRB ALL XPRNCG VSBYS UNDER 1SM. RUC BUFKIT
TEMP/DWPT PROFILES SHOW LOW LVL MOISTURE COLUMN THINNING 1ST AT
MRB ARND SUNRISE...THEN E OF THE MTNS BTWN 8 AND 9 AM. VFR CONDS
XPCTD AT ALL SITES THEREAFTER THROUGH THE DAYLGT HRS AND TNGT.
HIGH CLDS WL BEGIN TO OVRSPREAD FM THE SW AFTR MDNGT.
A LOW PRESSURE SYSTEM WILL QUICKLY SLIDE UP ACROSS THE AREA FROM THE
SW...FROM LATE MRNG WED THROUGH MIDDAY THU. MAINLY PERIODS OF RAIN
W/ BREEZY LOW LEVEL WINDS CLOSER TO THE MD BAY/DELMARVA. THE LOW
WILL MOVE NE ON THU...W/ A COUPLE OF BREEZY AND DRY UPPER LEVEL
SYSTEMS READY TO MOVE DOWN ACROSS THE REGION TO END THE WEEK. HIGH
PRESSURE WILL BEGIN IN FOR THE EARLY PART OF NEXT WEEK.
&&
.MARINE...
HV REISSUED THE SML CRFT ADVSRY TO INCLUDE ALL OF THE WATERS FOR
THE AFTN HRS. HIGH PRES BLDG INTO THE WATERS WL CAUSE A PD OF
15-20 KT WINDS. NO PROBS THIS MRNG OR TNGT.
A LOW PRESSURE SYSTEM WILL MOVE TOWARD THE AREA TODAY AND EARLY WED.
SCA CONDITIONS EXPECTED OVERNIGHT WED NIGHT INTO EARLY THU...AS A
STRENGTHENING SFC LOW DRIFTS UP THE I-95 CORRIDOR TOWARD THE LOWER
MD BAY/TP. THIS RAINY SYSTEM WILL RACE TOWARD NEW ENGLAND EARLY
THU...WHILE A COUPLE OF DRY AND BREEZY UPPER WAVES GEAR UP TO SWING
OVER THE AREA. THESE UPPER LEVEL FEATURES WILL BRING SCA CONDITIONS
TO THE AREA TO END THE WEEK.
&&
.TIDES/COASTAL FLOODING...
LOW PRESSURE APPROACHES AREA WED...AND PASSES NE OF REGION EARLY
THU. THERE WL BE A PERIOD OF STRONG ELY FLOW WED NIGHT...WHEN
TIDAL DEPARTURES MAY INCREASE BY A FT OR MORE. WE`RE JUST PAST
FULL MOON...SO THERE WL BE A TIDAL CONTRIBUTION AS WELL. MAY GET
CLOSE TO MINOR THRESHOLDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM EST THIS EVENING
FOR ANZ530>543.
SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 AM EST THURSDAY
FOR ANZ530>534-537>543.
&&
$$
PRODUCTS...WOODY!/GMS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
326 AM EST TUE JAN 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY. LOW PRESSURE WILL
TRACK INTO EAST TENNESSEE TUESDAY NIGHT BEFORE AFFECTING THE MID-
ATLANTIC REGION WEDNESDAY AND WEDNESDAY NIGHT. A COLD FRONT IS
EXPECTED TO CROSS THE REGION THURSDAY...USHERING IN MUCH COLDER
AIR FOR THE REGION.
&&
.NEAR TERM /TODAY/...
ATTM WE ARE KEEPING OUR EYES ON FOG AND LOW CLD. ON IR STLT IT IS
NOT IMMEDIATELY CLR WHERE THE CLDS ARE - BEST TO USE 11-3.9 MU
OVERLAIN W/ CIG/VSBY...AS WELL AS GO OUT AND LOOK AT THE SKY (AT
LEAST LOCALLY). BUT IT DOES APPEAR THAT DRIER AIR IS MOVG INTO THE
AREA AS W OF THE BLUE RDG NOT REPORTING ANY CLDS WHILE E OF THE
MTNS ARE SOCKED IN W/ OVC SKIES. IN A WAY THAT IS A BLESSING AS
THE LOW CLDS ARE PREVENTING THE RAD CONDS THAT COULD FACILITATE
DENSE FOG - E OF MTNS VSBYS GNRLY IN 2-4 MI RANGE ATTM WITH A FEW
OUTLIERS AT EITHER END OF THE SPECTRUM.
THERE WAS SOME WETNESS OVR MUCH OF THE CWA MON...AND THERE`LL BE
MORE ON WED...BUT TDA SHOULD BE DRY AS HIGH PRES MOVES INTO THE
AREA. WRLY WINDS WL BE DOWNSLOPING..AND IT SHOULDN`T BE LONG THIS
MRNG B4 THE SNOW THAT FELL MON IS GONE. TEMPS SHOULD TOP OUT IN
THE U40S/L50S W/ XCPTN OF M40S IN THE HIGHLANDS.
&&
.SHORT TERM /TONIGHT/...
THE EVE HRS SHOULD GNRLY BE CLR..ALLOWING TEMPS TO DROP THRU THE
40S FAIRLY QUICKLY. CLDS WL BEGIN TO INCRS AFTR MDNGT IN HIGHLAND/
PENDLETON AS THE NEXT SHORT WV TRACKS ACROSS THE GULF STATES.
BECAUSE OF THE INCRSG CLDS TEMPS WON`T GET QUITE AS COLD IN THE
CENTRAL SHEN VLLY AS THEY WL NEAR THE MASON-DIXON LN. TEMPS WL
RANGE FM THE MU20S N TO M30S S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A COUPLE OF VERY DIFFERENT BUT COMPLEX LOW PRESSURE SYSTEMS WILL
MERGE JUST NORTH OF THE AREA MID WEEK. BEFORE THEN...AND OVER THE
NEXT 2 DAYS - THESE WILL BE MAKING THEIR WAY TO THE MID ATLC /ONE
FROM THE NRN PLAINS AND ONE FROM THE SRN PLAINS/. THE SRN PLAINS
SYSTEM WILL BRING STEADY RAINS TO THE AREA ON WED-EARLY
THU...ARRIVING JUST AHEAD OF THE DRIER AND COLDER NRN PLAINS
SYSTEM. BOTH CLOSED UPPER LOWS WILL STRENGTHEN OVER THE NEXT 24-36
HRS AS THEY APPROACH OUR AREA. THE SRN PLAINS LOW THAT HAS ALREADY
SPREAD MODERATE TO HEAVY RAINFALL FROM TX/OK TO THE MISSISSIPPI
VLY WILL CONTINUE TO DEEPEN AS IT MOVES DUE EAST TODAY.
BY EARLY WED...THE NRN PLAINS LOW WILL QUICKLY DROP SWD AND PUSH THE
SRN PLAINS LOW RIGHT UP THE ERN SEABOARD ONCE IT REACHES THE APLCNS.
BEFORE THEN...THE LOW WILL HAVE TAPPED INTO A BETTER GULF MOISTURE
FETCH AS BEGIN TO PULL THAT LOW LEVEL MOISTURE UP ACROSS THE
CAROLINAS AND THE LEE SIDE OF THE BLUE RIDGE. DRIER WLY WINDS FROM
TODAY AND TONIGHT WILL KEEP THE LOW LEVEL CONDITIONS FAVORABLE FOR A
RAIN-SNOW MIX AT ONSET OF PRECIP AFTER DAWN ON WED. AS THE SFC LOW
STRENGTHENS AND DRIFTS UP THE I-95 CORRIDOR...RELATIVELY WARMER AND
MORE MOIST ELY ONSHORE FLOW WILL HELP TEMPER THESE LOW LEVEL
CONDITIONS AND MAKE FOR MORE OF A COLD RAIN HEADING INTO THE AFTN
HRS. STEADY BATCHES OF RAIN WILL MOVE OVER THE REGION LATER IN THE
DAY AND ESPECIALLY FOR THE LATE NIGHT HRS. AVG MODEL QPFS RANGE IN
THE 0.50-1.00 INCH RANGE W/ LOCALLY HIGHER AMNTS ALONG AND E OF
I-95. MUCH OF THIS WILL BE STRETCHED OUT OVER A BETTER PART OF THE
DAY/EVE.
THE NRN PLAINS UPPER LOW WILL THEN KICK OUT THIS SYSTEM QUICKLY UP
ACROSS THE SRN NEW ENGLAND COAST. BY EARLY THU...PRECIP WILL BE
DISSIPATING OVER THE PIEDMONT BUT ANOTHER COLD SURGE WILL BE RIGHT
ON ITS HEELS. AS THE NEW ENGLAND SYSTEM RACES OFF THE COAST...THE
GREAT LAKES UPPER LOW WILL HAVE A COUPLE MORE DAYS TO SLOWLY ROTATE
EWD. COLDER AND DRIER CANADIAN AIR WILL BE ON THE WAY...THOUGH NOT
AS COLD AS OUR RECENT BOUT. CONDITIONS TO CLOSE OUT THE WEEK WILL BE
BLUSTERY AND COLD...W/ A RETURN TO THE DRIER AIR OF DEWPOINTS IN THE
SINGLE DIGITS AND TEENS AGAIN. THIS SYSTEM WILL MAKE AN EXIT OFF THE
COAST ON SAT...BUT ANOTHER REINFORCING SHOT OF COLD-DRY AIR WILL
COME IN FROM BEHIND ON SUN. A GRADUAL RETURN TO MORE MILD CONDITIONS
/THOUGH STILL MAINLY DRY/ FOR EARLY NEXT WEEK.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
LOW VSBYS IN FOG AT THE SITES OUTSIDE OF THE MAJOR CITIES. THESE
ARE XPCTD TO IMPROVE THIS MRNG AS HIGH BUILDS INTO THE MID ATLC.
ATTM IAD...CHO...MRB ALL XPRNCG VSBYS UNDER 1SM. RUC BUFKIT
TEMP/DWPT PROFILES SHOW LOW LVL MOISTURE COLUMN THINNING 1ST AT
MRB ARND SUNRISE...THEN E OF THE MTNS BTWN 8 AND 9 AM. VFR CONDS
XPCTD AT ALL SITES THEREAFTER THROUGH THE DAYLGT HRS AND TNGT.
HIGH CLDS WL BEGIN TO OVRSPREAD FM THE SW AFTR MDNGT.
A LOW PRESSURE SYSTEM WILL QUICKLY SLIDE UP ACROSS THE AREA FROM THE
SW...FROM LATE MRNG WED THROUGH MIDDAY THU. MAINLY PERIODS OF RAIN
W/ BREEZY LOW LEVEL WINDS CLOSER TO THE MD BAY/DELMARVA. THE LOW
WILL MOVE NE ON THU...W/ A COUPLE OF BREEZY AND DRY UPPER LEVEL
SYSTEMS READY TO MOVE DOWN ACROSS THE REGION TO END THE WEEK. HIGH
PRESSURE WILL BEGIN IN FOR THE EARLY PART OF NEXT WEEK.
&&
.MARINE...
HV REISSUED THE SML CRFT ADVSRY TO INCLUDE ALL OF THE WATERS FOR
THE AFTN HRS. HIGH PRES BLDG INTO THE WATERS WL CAUSE A PD OF
15-20 KT WINDS. NO PROBS THIS MRNG OR TNGT.
A LOW PRESSURE SYSTEM WILL MOVE TOWARD THE AREA TODAY AND EARLY WED.
SCA CONDITIONS EXPECTED OVERNIGHT WED NIGHT INTO EARLY THU...AS A
STRENGTHENING SFC LOW DRIFTS UP THE I-95 CORRIDOR TOWARD THE LOWER
MD BAY/TP. THIS RAINY SYSTEM WILL RACE TOWARD NEW ENGLAND EARLY
THU...WHILE A COUPLE OF DRY AND BREEZY UPPER WAVES GEAR UP TO SWING
OVER THE AREA. THESE UPPER LEVEL FEATURES WILL BRING SCA CONDITIONS
TO THE AREA TO END THE WEEK.
&&
.TIDES/COASTAL FLOODING...
LOW PRESSURE APPROACHES AREA WED...AND PASSES NE OF REGION EARLY
THU. THERE WL BE A PERIOD OF STRONG ELY FLOW WED NIGHT...WHEN
TIDAL DEPARTURES MAY INCREASE BY A FT OR MORE. WE`RE JUST PAST
FULL MOON...SO THERE WL BE A TIDAL CONTRIBUTION AS WELL. MAY GET
CLOSE TO MINOR THRESHOLDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM EST THIS EVENING
FOR ANZ530>543.
&&
$$
PRODUCTS...WOODY!/GMS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
302 PM MST TUE JAN 10 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH THURSDAY...
ARCTIC COLD FRONT HAS PASSED BY A LINE FROM PLENTYWOOD THROUGH
GLASGOW THIS AFTERNOON AND IS PROGRESSING SOUTHEASTWARD. AREAS
AHEAD OF THE FRONT HAVE ALL RAIN WHILE AREAS BEHIND THE FRONT HAVE
ALL SNOW. MODEL BLEND GIVES A HALF INCH TO AN INCH AND A HALF OF
TOTAL SNOW FALL ACCUMULATION BEHIND THE FRONT. PRECIPITATION
WILL BEGIN TO DECLINE BY MIDNIGHT
WINDS BEHIND THE FRONT ARE CURRENTLY NORTHWESTERLY AT 15 TO 20 MPH
AND WILL INCREASE TO 20 TO 25 MPH OVER NIGHT. COLD ADVECTION
BEHIND THE FRONT WILL DROP TEMPERATURES STEADILY ALL NIGHT.
TEMPERATURE WILL REACH NEAR 0 ALONG THE INTERNATIONAL BORDER BY
MORNING. THIS WILL COMBINE WITH WIND TO PRODUCE BITTER COLD WIND
CHILL DOWN TO 22 BELOW FOR AREAS NEAR THE INTERNATIONAL BORDER.
BLOWING SNOW AND REDUCED VISIBILITY IS A LIKELY IMPACT FROM THE
SNOW AND WIND COMBINATION TONIGHT...HOWEVER...RELATIVELY LIGHT
SNOW SEEN SO FAR SHOULD LEAD TO VISIBILITIES GENERALLY A HALF MILE
OR BETTER. SNOW AMOUNTS SHOULD ALSO DECLINE AFTER DARK. SHOULD
OBSERVATIONS SHOW WORSE CONDITIONS...AN ADVISORY MAY BE NEEDED.
COLD FRONT THAT PASSED THROUGH GLASGOW THIS AFTERNOON IS RELATED
TO A MIDLEVEL TROUGH THAT IS DIGGING SOUTHEASTWARD THROUGH IDAHO
AND EASTERN MONTANA. TEMPERATURES WILL BE BACK DOWN TO NEAR
SEASONAL NORMAL WEDNESDAY AND THURSDAY BEHIND THE FRONT. HOW COLD
IT WILL ACTUALLY GET WILL DEPEND ON HOW MUCH SNOW ACCUMULATION
WILL OCCUR AND HOW MUCH CLOUD COVER. THURSDAY MORNING IS EXPECTED
TO THE BE COLDEST TIME WITH LOWS DOWN BELOW ZERO IN MOST PLACES.
MARTIN
PREVIOUS SHORT TERM DISCUSSION... WATER VAPOR IMAGERY AND 500 MB
HEIGHT FIELD SHOWING A REX BLOCK UPPER LEVEL FLOW PATTERN ACROSS
THE CONUS. THE CUT-OFF UPPER LOW CENTER IS SPINNING OVER EASTERN
TEXAS AND SETTING OFF THUNDERSTORMS OVER THE RED RIVER REGION AND
THE NORTHERN GULF SHORES. AN ELONGATED BUT RELATIVELY CALM UPPER
TROUGH IS MOVING OVER NEW ENGLAND. UPPER LEVEL ZONAL FLOW IS IN
PLACE OVER THE NORTHERN HIGH PLAINS...NORTH OF THE CUT-OFF LOW.
SHORT WAVE RIDGING FAVORS THE FAR SOUTHWESTERN CONUS. A NEW UPPER
LEVEL TROUGH HAS MOVED ON SHORE OVER THE PACIFIC NORTHWEST.
THIS APPROACHING WESTERN TROUGH IS PUSHING A FAIR AMOUNT OF
PACIFIC MOISTURE ALONG AND AHEAD OF IT OVER THE NORTHERN ROCKIES.
IT ALSO SHOWS A VERY DISTINCT CLEARING LINE ALONG THE TROUGH AXIS.
THE ARCTIC TROUGH ON THE EASTERN SLOPES OF THE CANADIAN ROCKIES IS
NOW BEGINNING TO TAKE SHAPE AND THE WEST COAST TROUGH IS BEGINNING
TO CLOSE OFF OVER THE NORTHERN CALIFORNIA COAST.
ENOUGH MOISTURE IS MAKING IT EASTWARD OF THE ROCKIES TO BEGIN A
FEW SPRINKLES OVER OUR WESTERN ZONES. THIS IS SOMEWHAT OF A
CHALLENGING FORECAST. FOR WHATEVER REASON...OVERNIGHT LOW
TEMPERATURES THIS MORNING ARE NOT DROPPING ANYWHERE NEAR THE
EXPECTED LEVELS. NEEDED TO MAKE SOME SIGNIFICANT
ADJUSTMENTS...WHICH IN TURN HAVE REDUCED THE EXPECTED OVERALL SNOW
FALL WITH THIS SYSTEM. DO NOT KNOW EXACTLY WHY THIS IS HAPPENING.
WINDS ARE NEAR CALM AND CLOUD COVER IS THERE...BUT IT IS NOT
SIGNIFICANTLY THICK ENOUGH TO USUALLY CAUSE NIGHT TIME
TEMPERATURES TO HOLD SO WARM REGARDLESS OF THE DAY TIME HIGH
TEMPERATURES. ANYWAY...HIGH TEMPERATURES TODAY WILL BE ABLE TO
CLIMB AGAIN OVER OUR CENTRAL AND SOUTHERN ZONES BEFORE THE COLD
FRONT SLIDES SOUTHWARD. THIS WILL LIKELY KEEP MOST OF THE EXPECTED
PRECIPITATION AS RAIN.
WITH THE ARRIVAL OF THE COLD FRONT THIS AFTERNOON...EXPECT ALL
PRECIPITATION TO CHANGE OVER TO SNOW...COINCIDENT WITH
NORTHWESTERLY WINDS INCREASING INTO THE 25G35KT RANGE. AREAS OF
BLOWING SNOW WILL BE POSSIBLE. NOT A WHOLE LOT OF CONFIDENCE IN
THIS FORECAST GIVEN THE POOR MODEL RUN TO RUN CONSISTENCY. EACH
SUCCESSIVE MODEL RUN SEEMS TO BE BACKING OFF THE QPF AND BRINGING
IN A KIND OF DRY SLOT OVER OUR CENTRAL CWA. OVERNIGHT LOW
TEMPERATURES THIS MORNING NOWHERE NEAR THE EXPECTED LEVELS.
TEMPERATURES REMAINED RELATIVELY WARM.
THE HRRR MODEL SOLUTION HAS BEEN HELPFULLY ACCURATE IN DEPICTING
THE ONSET OF THE SPRINKLES OVER OUR WESTERN AND SOUTHWESTERN ZONES
AS EVIDENCES BY RADAR REFLECTIVITIES EARLY THIS MORNING. ACCORDING
THE OPERATIONAL SHORT TERM MODEL SOLUTIONS...JUST AS SOON AS THE
PRECIPITATION GETS GOING OVER OUR NORTHWESTERN ZONES THIS
MORNING...A DRY SLOT HOLE QUICKLY OPENS UP AND CUTS OF THE
MOISTURE. I IMAGINE THERE WILL BE NEED FOR UPDATES TO KEEP UP WITH
THE UNCERTAINTY WITH THIS SYSTEM.
BY WEDNESDAY MORNING...ON THE BACKSIDE OF THIS SYSTEM...SNOW
SHOWERS WILL LINGER OVER OUR EASTERN AND NORTHEASTERN ZONES...THEN
SLIDE EASTWARD AWAY FROM OUR CWA BY WEDNESDAY EVENING WITH
DRASTICALLY CLEARING SKIES APPROACHING FROM THE WEST. THE ARCTIC
AIR WILL DROP OVERNIGHT LOWS TO NEAR ZERO DEGREES BOTH WEDNESDAY
AND THURSDAY MORNING. WINDS WILL BE ABOVE 10 KNOTS. EXPECT WIND
CHILLS TO DROP DOWN NEAR 20 DEGREES BELOW ZERO FOR A FEW OF OUR
NORTHERN AND EASTERN ZONES. A WIND CHILL ADVISORY MAY BE NEEDED.
THURSDAY WILL BE QUIET AS TEMPERATURES BEGIN TO RECOVER AND
MODERATE ABOVE NORMAL AGAIN AND CALM WIND TURN MORE OUT OF THE
WEST. BMICKELSON
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE OFF THE COAST OF CALIFORNIA CONTINUES TO ANCHOR AN
UPPER LEVEL RIDGE OVER THE WEST FRIDAY AND SATURDAY. THIS WILL
MAINTAIN MILD CONDITIONS WITH TEMPERATURES AROUND 10*F TO 15*F
ABOVE NORMAL THROUGH SUNDAY. THE NEXT UPPER LEVEL TROUGH AND
ASSOCIATED ARCTIC COLD FRONT DROP INTO WESTERN CANADA THIS
WEEKEND. TIMING DIFFERS BETWEEN THE GFS AND EC. THE MON 00Z EC
BRINGS THE FRONT ACROSS THE INTERNATIONAL BORDER SATURDAY NIGHT.
THE 12Z GFS IS SLOWER...BRINGING THE FRONT OVER THE BORDER SUNDAY
NIGHT. HOWEVER THE 12Z EC CAME IN MUCH MORE IN LINE WITH THE GFS.
A MODERATE AMOUNT OF PACIFIC MOISTURE OVERRUNNING THE FRONT WILL
PRODUCE SNOW OVER MONTANA. NORTHEAST MONTANA MIGHT BE DRY
SLOTTED...EXCEPT FOR THE SOUTHWEST AREAS. QPF WILL NOT BE
SUBSTANTIAL...SO NO MORE THAN AN INCH OR TWO IS EXPECTED. THE MAIN
STORY WILL BE THE DROPPING TEMPERATURES. A POLAR AIR MASS
CURRENTLY HOVERING OVER THE ARCTIC OCEAN NORTH OF ALASKA SLIDES
SOUTH OVER CANADA. BOTH THE GFS AND EC HAVE 850MB TEMPERATURES
NEAR PLENTYWOOD AT AROUND -24*C BY 00Z TUESDAY. THEREFORE HIGHS
EARLY NEXT WEEK WILL RANGE IN THE SINGLE DIGITS AND LOWER TEENS.
A FEW MINOR GRID EDITS WERE MADE TO POPS FOR EARLY NEXT WEEK.
TEMPERATURES WERE ALSO LOWERED TO CONTINUE THE TREND TO COLDER
AIR. SCT
PREVIOUS DISCUSSION...
MILD WEATHER IS EXPECTED FRIDAY AND SATURDAY. SHORTWAVE TROUGH IN
NORTHWEST FLOW ALOFT WITH WEAK COLD FRONT PASSES THROUGH THE
REGION WITH LIMITED MOISTURE. NOT SURE IF THERE WILL BE ENOUGH
MOISTURE FOR ANY PRECIPITATION. WILL MAINTAIN 10 POPS WITH NO
MENTION OF PRECIP FOR NOW.
ONE MORE SHORTWAVE RIDGE PASSES THROUGH MONTANA ON SATURDAY BEFORE
STRONG COLD FRONT DROPS SOUTH SATURDAY NIGHT AND SUNDAY. AT THIS
POINT...SATURDAY MAY BE THE LAST WARM DAY NORTHEAST MONTANA SEES
FOR A WHILE AS THE ECMWF...GEM AND TO A LESSER DEGREE THE GFS WANT
TO BREAK DOWN THE WEST COAST RIDGE THAT HAS PROVIDED MONTANA THE
UNSEASONABLY WARM WEATHER THE LAST FEW WEEKS. LIMITED MOISTURE IS
EXPECTED WITH THE INITIAL COLD FRONT. WILL MAINTAIN DRY FORECAST
FOR NOW. ARCTIC AIRMASS SETTLES INTO THE REGION SUNDAY NIGHT BUT
THE COLDEST AIR WILL STAY TO THE NORTH FOR MONDAY AND TUESDAY SO
TEMPERATURES WILL BE SOMEWHAT BELOW NORMAL. MODELS DIFFER ON
WHETHER OR NOT THERE WILL BE ENOUGH OVERRUNNING MOISTURE FOR SNOW
ON MONDAY AND TUESDAY WITH A SYSTEM TO THE SOUTH OF THE FORECAST
AREA. ARCTIC HIGH PRESSURE OVER SASKATCHEWAN MAY ALSO LIMIT PRECIP
CHANCES. WILL MENTION A SLIGHT CHANCE FOR NOW. FORRESTER
&&
.AVIATION...
AN ARCTIC COLD FRONT DROPPING SOUTH OVER THE AREA BROUGHT RAIN
THIS MORNING THAT TRANSITIONED OVER TO SNOW THIS AFTERNOON. THESE
SNOW SHOWERS SHOULD TAPER OFF BY EVENING. THEREFORE EXPECT
PERIODS OF IFR CEILINGS AND VISIBILITIES. STRONG NORTHERLY WINDS
OF 15 TO 25 KTS BEHIND THE FRONT ARE EXPECTED TO REMAIN STRONG
THROUGHOUT THE NIGHT AS SKIES CLEAR FROM THE NORTH. WINDS ON
WEDNESDAY WILL CONTINUE STRONG AT AROUND 20KTS. SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 10 AM MST
THURSDAY FOR DANIELS...SHERIDAN...NORTHERN VALLEY.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
934 AM MST TUE JAN 10 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
SCATTERED AREAS OF LIGHT RAIN OVER ABOUT THE NORTHWESTERN TWO
THIRDS OF THE CWA THIS MORNING SHOULD REMAIN RAIN UNTIL THE
PASSAGE OF A COLD FRONT THIS AFTERNOON. COLD FRONT...CURRENTLY IN
CANADA...WILL ENTER NORTHWESTERN SECTIONS OF THE AREA AFTER NOON
AND PUSH THROUGH THE AREA BY NIGHTFALL. PRECIPITATION BEHIND THE
FRONT WILL BE SNOW...BUT WILL BE LIGHTER THAN THE RAIN AHEAD OF
THE FRONT. WINDS WILL ALSO BE BRISK AND FROM THE NORTH BEHIND THE FRONT.
SNOW ACCUMULATIONS BEHIND THE FRONT WILL NOT BE HEAVY...AND WILL
RANGE FROM ZERO TO 1 INCH. MARTIN.
PREVIOUS SHORT TERM DISCUSSION...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWING A REX BLOCK
UPPER LEVEL FLOW PATTERN ACROSS THE CONUS. THE CUT-OFF UPPER LOW
CENTER IS SPINNING OVER EASTERN TEXAS AND SETTING OFF
THUNDERSTORMS OVER THE RED RIVER REGION AND THE NORTHERN GULF
SHORES. AN ELONGATED BUT RELATIVELY CALM UPPER TROUGH IS MOVING
OVER NEW ENGLAND. UPPER LEVEL ZONAL FLOW IS IN PLACE OVER THE
NORTHERN HIGH PLAINS...NORTH OF THE CUT-OFF LOW. SHORT WAVE
RIDGING FAVORS THE FAR SOUTHWESTERN CONUS. A NEW UPPER LEVEL TROUGH
HAS MOVED ON SHORE OVER THE PACIFIC NORTHWEST.
THIS APPROACHING WESTERN TROUGH IS PUSHING A FAIR AMOUNT OF
PACIFIC MOISTURE ALONG AND AHEAD OF IT OVER THE NORTHERN ROCKIES.
IT ALSO SHOWS A VERY DISTINCT CLEARING LINE ALONG THE TROUGH AXIS.
THE ARCTIC TROUGH ON THE EASTERN SLOPES OF THE CANADIAN ROCKIES IS
NOW BEGINNING TO TAKE SHAPE AND THE WEST COAST TROUGH IS BEGINNING
TO CLOSE OFF OVER THE NORTHERN CALIFORNIA COAST.
ENOUGH MOISTURE IS MAKING IT EASTWARD OF THE ROCKIES TO BEGIN A
FEW SPRINKLES OVER OUR WESTERN ZONES. THIS IS SOMEWHAT OF A
CHALLENGING FORECAST. FOR WHATEVER REASON...OVERNIGHT LOW
TEMPERATURES THIS MORNING ARE NOT DROPPING ANYWHERE NEAR THE
EXPECTED LEVELS. NEEDED TO MAKE SOME SIGNIFICANT
ADJUSTMENTS...WHICH IN TURN HAVE REDUCED THE EXPECTED OVERALL SNOW
FALL WITH THIS SYSTEM. DO NOT KNOW EXACTLY WHY THIS IS HAPPENING.
WINDS ARE NEAR CALM AND CLOUD COVER IS THERE...BUT IT IS NOT
SIGNIFICANTLY THICK ENOUGH TO USUALLY CAUSE NIGHT TIME
TEMPERATURES TO HOLD SO WARM REGARDLESS OF THE DAY TIME HIGH
TEMPERATURES. ANYWAY...HIGH TEMPERATURES TODAY WILL BE ABLE TO
CLIMB AGAIN OVER OUR CENTRAL AND SOUTHERN ZONES BEFORE THE COLD
FRONT SLIDES SOUTHWARD. THIS WILL LIKELY KEEP MOST OF THE EXPECTED
PRECIPITATION AS RAIN.
WITH THE ARRIVAL OF THE COLD FRONT THIS AFTERNOON...EXPECT ALL
PRECIPITATION TO CHANGE OVER TO SNOW...COINCIDENT WITH
NORTHWESTERLY WINDS INCREASING INTO THE 25G35KT RANGE. AREAS OF
BLOWING SNOW WILL BE POSSIBLE. NOT A WHOLE LOT OF CONFIDENCE IN
THIS FORECAST GIVEN THE POOR MODEL RUN TO RUN CONSISTENCY. EACH
SUCCESSIVE MODEL RUN SEEMS TO BE BACKING OFF THE QPF AND BRINGING
IN A KIND OF DRY SLOT OVER OUR CENTRAL CWA. OVERNIGHT LOW
TEMPERATURES THIS MORNING NOWHERE NEAR THE EXPECTED LEVELS.
TEMPERATURES REMAINED RELATIVELY WARM.
THE HRRR MODEL SOLUTION HAS BEEN HELPFULLY ACCURATE IN DEPICTING
THE ONSET OF THE SPRINKLES OVER OUR WESTERN AND SOUTHWESTERN ZONES
AS EVIDENCES BY RADAR REFLECTIVITIES EARLY THIS MORNING. ACCORDING
THE OPERATIONAL SHORT TERM MODEL SOLUTIONS...JUST AS SOON AS THE
PRECIPITATION GETS GOING OVER OUR NORTHWESTERN ZONES THIS
MORNING...A DRY SLOT HOLE QUICKLY OPENS UP AND CUTS OF THE
MOISTURE. I IMAGINE THERE WILL BE NEED FOR UPDATES TO KEEP UP WITH
THE UNCERTAINTY WITH THIS SYSTEM.
BY WEDNESDAY MORNING...ON THE BACKSIDE OF THIS SYSTEM...SNOW
SHOWERS WILL LINGER OVER OUR EASTERN AND NORTHEASTERN ZONES...THEN
SLIDE EASTWARD AWAY FROM OUR CWA BY WEDNESDAY EVENING WITH
DRASTICALLY CLEARING SKIES APPROACHING FROM THE WEST. THE ARCTIC
AIR WILL DROP OVERNIGHT LOWS TO NEAR ZERO DEGREES BOTH WEDNESDAY
AND THURSDAY MORNING. WINDS WILL BE ABOVE 10 KNOTS. EXPECT WIND
CHILLS TO DROP DOWN NEAR 20 DEGREES BELOW ZERO FOR A FEW OF OUR
NORTHERN AND EASTERN ZONES. A WIND CHILL ADVISORY MAY BE NEEDED.
THURSDAY WILL BE QUIET AS TEMPERATURES BEGIN TO RECOVER AND
MODERATE ABOVE NORMAL AGAIN AND CALM WIND TURN MORE OUT OF THE
WEST. BMICKELSON
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
MILD WEATHER IS EXPECTED FRIDAY AND SATURDAY. SHORTWAVE TROUGH IN
NORTHWEST FLOW ALOFT WITH WEAK COLD FRONT PASSES THROUGH THE
REGION WITH LIMITED MOISTURE. NOT SURE IF THERE WILL BE ENOUGH
MOISTURE FOR ANY PRECIPITATION. WILL MAINTAIN 10 POPS WITH NO
MENTION OF PRECIP FOR NOW.
ONE MORE SHORTWAVE RIDGE PASSES THROUGH MONTANA ON SATURDAY BEFORE
STRONG COLD FRONT DROPS SOUTH SATURDAY NIGHT AND SUNDAY. AT THIS
POINT...SATURDAY MAY BE THE LAST WARM DAY NORTHEAST MONTANA SEES
FOR A WHILE AS THE ECMWF...GEM AND TO A LESSER DEGREE THE GFS WANT
TO BREAK DOWN THE WEST COAST RIDGE THAT HAS PROVIDED MONTANA THE
UNSEASONABLY WARM WEATHER THE LAST FEW WEEKS. LIMITED MOISTURE IS
EXPECTED WITH THE INITIAL COLD FRONT. WILL MAINTAIN DRY FORECAST
FOR NOW. ARCTIC AIRMASS SETTLES INTO THE REGION SUNDAY NIGHT BUT
THE COLDEST AIR WILL STAY TO THE NORTH FOR MONDAY AND TUESDAY SO
TEMPERATURES WILL BE SOMEWHAT BELOW NORMAL. MODELS DIFFER ON
WHETHER OR NOT THERE WILL BE ENOUGH OVERRUNNING MOISTURE FOR SNOW
ON MONDAY AND TUESDAY WITH A SYSTEM TO THE SOUTH OF THE FORECAST
AREA. ARCTIC HIGH PRESSURE OVER SASKATCHEWAN MAY ALSO LIMIT PRECIP
CHANCES. WILL MENTION A SLIGHT CHANCE FOR NOW. FORRESTER
&&
.AVIATION...
VFR. MID AND HIGH LEVEL CLOUDS WILL GRADUALLY THICKEN AND LOWER
EARLY THIS MORNING. LOW CLOUDS WILL MOVE INTO THE AREA AFTER
SUNRISE WITH RAIN SHOWERS POSSIBLE THAT WILL CHANGE INTO SNOW
SHOWERS BY EARLY AFTERNOON. CEILINGS WILL HOVER NEAR THE MVFR/VFR
THRESHOLD OF 3000 FEET THIS AFTERNOON. WEST WINDS AROUND 10 KNOTS
EARLY WILL TURN NORTHWEST 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER
A COLD FRONT MOVES THROUGH THE AREA THIS MORNING. THE GUSTY
NORTHWEST WINDS WILL CONTINUE TONIGHT WITH A MIX OF LOW AND MID
LEVEL CLOUDS.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
351 AM MST TUE JAN 10 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWING A REX BLOCK
UPPER LEVEL FLOW PATTERN ACROSS THE CONUS. THE CUT-OFF UPPER LOW
CENTER IS SPINNING OVER EASTERN TEXAS AND SETTING OFF
THUNDERSTORMS OVER THE RED RIVER REGION AND THE NORTHERN GULF
SHORES. AN ELONGATE BUT RELATIVELY CALM UPPER TROUGH IS MOVING
OVER NEW ENGLAND. UPPER LEVEL ZONAL FLOW IS IN PLACE OVER THE
NORTHERN HIGH PLAINS...NORTH OF THE CUT-OFF LOW. SHORT WAVE
RIDGING FAVORS THE FAR SOUTHWESTERN CONUS. A NEW UPPER LEVEL TROUGH
HAS MOVED ON SHORE OVER THE PACIFIC NORTHWEST.
THIS APPROACHING WESTERN TROUGH IS PUSHING A FAIR AMOUNT OF
PACIFIC MOISTURE ALONG AND AHEAD OF IT OVER THE NORTHERN ROCKIES.
IT ALSO SHOWS A VERY DISTINCT CLEARING LINE ALONG THE TROUGH AXIS.
THE ARCTIC TROUGH ON THE EASTERN SLOPES OF THE CANADIAN ROCKIES IS
NOW BEGINNING TO TAKE SHAPE AND THE WEST COAST TROUGH IS BEGINNING
TO CLOSE OFF OVER THE NORTHERN CALIFORNIA COAST.
ENOUGH MOISTURE IS MAKING IT EASTWARD OF THE ROCKIES TO BEGIN A
FEW SPRINKLES OVER OUR WESTERN ZONES. THIS IS SOMEWHAT OF A
CHALLENGING FORECAST. FOR WHATEVER REASON...OVERNIGHT LOW
TEMPERATURES THIS MORNING ARE NOT DROPPING ANYWHERE NEAR THE
EXPECTED LEVELS. NEEDED TO MAKE SOME SIGNIFICANT
ADJUSTMENTS...WHICH IN TURN HAVE REDUCED THE EXPECTED OVERALL SNOW
FALL WITH THIS SYSTEM. DO NOT KNOW EXACTLY WHY THIS IS HAPPENING.
WINDS ARE NEAR CALM AND CLOUD COVER IS THERE...BUT IT IS NOT
SIGNIFICANTLY THICK ENOUGH TO USUALLY CAUSE NIGHT TIME
TEMPERATURES TO HOLD SO WARM REGARDLESS OF THE DAY TIME HIGH
TEMPERATURES. ANYWAY...HIGH TEMPERATURES TODAY WILL BE ABLE TO
CLIMB AGAIN OVER OUR CENTRAL AND SOUTHERN ZONES BEFORE THE COLD
FRONT SLIDES SOUTHWARD. THIS WILL LIKELY KEEP MOST OF THE EXPECTED
PRECIPITATION AS RAIN.
WITH THE ARRIVAL OF THE COLD FRONT THIS AFTERNOON...EXPECT ALL
PRECIPITATION TO CHANGE OVER TO SNOW...COINCIDENT WITH
NORTHWESTERLY WINDS INCREASING INTO THE 25G35KT RANGE. AREAS OF
BLOWING SNOW WILL BE POSSIBLE. NOT A WHOLE LOT OF CONFIDENCE IN
THIS FORECAST GIVEN THE POOR MODEL RUN TO RUN CONSISTENCY. EACH
SUCCESSIVE MODEL RUN SEEMS TO BE BACKING OFF THE QPF AND BRINGING
IN A KIND OF DRY SLOT OVER OUR CENTRAL CWA. OVERNIGHT LOW
TEMPERATURES THIS MORNING NOWHERE NEAR THE EXPECTED LEVELS.
TEMPERATURES REMAINED RELATIVELY WARM.
THE HRRR MODEL SOLUTION HAS BEEN HELPFULLY ACCURATE IN DEPICTING
THE ONSET OF THE SPRINKLES OVER OUR WESTERN AND SOUTHWESTERN ZONES
AS EVIDENCES BY RADAR REFLECTIVITIES EARLY THIS MORNING. ACCORDING
THE OPERATIONAL SHORT TERM MODEL SOLUTIONS...JUST AS SOON AS THE
PRECIPITATION GETS GOING OVER OUR NORTHWESTERN ZONES THIS
MORNING...A DRY SLOT HOLE QUICKLY OPENS UP AND CUTS OF THE
MOISTURE. I IMAGINE THERE WILL BE NEED FOR UPDATES TO KEEP UP WITH
THE UNCERTAINTY WITH THIS SYSTEM.
BY WEDNESDAY MORNING...ON THE BACKSIDE OF THIS SYSTEM...SNOW
SHOWERS WILL LINGER OVER OUR EASTERN AND NORTHEASTERN ZONES...THEN
SLIDE EASTWARD AWAY FROM OUR CWA BY WEDNESDAY EVENING WITH
DRASTICALLY CLEARING SKIES APPROACHING FROM THE WEST. THE ARCTIC
AIR WILL DROP OVERNIGHT LOWS TO NEAR ZERO DEGREES BOTH WEDNESDAY
AND THURSDAY MORNING. WINDS WILL BE ABOVE 10 KNOTS. EXPECT WIND
CHILLS TO DROP DOWN NEAR 20 DEGREES BELOW ZERO FOR A FEW OF OUR
NORTHERN AND EASTERN ZONES. A WIND CHILL ADVISORY MAY BE NEEDED.
THURSDAY WILL BE QUIET AS TEMPERATURES BEGIN TO RECOVER AND
MODERATE ABOVE NORMAL AGAIN AND CALM WIND TURN MORE OUT OF THE
WEST. BMICKELSON
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
MILD WEATHER IS EXPECTED FRIDAY AND SATURDAY. SHORTWAVE TROUGH IN
NORTHWEST FLOW ALOFT WITH WEAK COLD FRONT PASSES THROUGH THE
REGION WITH LIMITED MOISTURE. NOT SURE IF THERE WILL BE ENOUGH
MOISTURE FOR ANY PRECIPITATION. WILL MAINTAIN 10 POPS WITH NO
MENTION OF PRECIP FOR NOW.
ONE MORE SHORTWAVE RIDGE PASSES THROUGH MONTANA ON SATURDAY BEFORE
STRONG COLD FRONT DROPS SOUTH SATURDAY NIGHT AND SUNDAY. AT THIS
POINT...SATURDAY MAY BE THE LAST WARM DAY NORTHEAST MONTANA SEES
FOR A WHILE AS THE ECMWF...GEM AND TO A LESSER DEGREE THE GFS WANT
TO BREAK DOWN THE WEST COAST RIDGE THAT HAS PROVIDED MONTANA THE
UNSEASONABLY WARM WEATHER THE LAST FEW WEEKS. LIMITED MOISTURE IS
EXPECTED WITH THE INITIAL COLD FRONT. WILL MAINTAIN DRY FORECAST
FOR NOW. ARCTIC AIR MASS SETTLES INTO THE REGION SUNDAY NIGHT BUT
THE COLDEST AIR WILL STAY TO THE NORTH FOR MONDAY AND TUESDAY SO
TEMPERATURES WILL BE SOMEWHAT BELOW NORMAL. MODELS DIFFER ON
WHETHER OR NOT THERE WILL BE ENOUGH OVERRUNNING MOISTURE FOR SNOW
ON MONDAY AND TUESDAY WITH A SYSTEM TO THE SOUTH OF THE FORECAST
AREA. ARCTIC HIGH PRESSURE OVER SASKATCHEWAN MAY ALSO LIMIT PRECIP
CHANCES. WILL MENTION A SLIGHT CHANCE FOR NOW. FORRESTER
&&
.AVIATION...
VFR. MID AND HIGH LEVEL CLOUDS WILL GRADUALLY THICKEN AND LOWER
EARLY THIS MORNING. LOW CLOUDS WILL MOVE INTO THE AREA AFTER
SUNRISE WITH RAIN SHOWERS POSSIBLE THAT WILL CHANGE INTO SNOW
SHOWERS BY EARLY AFTERNOON. CEILINGS WILL HOVER NEAR THE MVFR/VFR
THRESHOLD OF 3000 FEET THIS AFTERNOON. WEST WINDS AROUND 10 KNOTS
EARLY WILL TURN NORTHWEST 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER
A COLD FRONT MOVES THROUGH THE AREA THIS MORNING. THE GUSTY
NORTHWEST WINDS WILL CONTINUE TONIGHT WITH A MIX OF LOW AND MID
LEVEL CLOUDS.
&&
.CLIMATE...
MANY NEW RECORD HIGH TEMPERATURES ACROSS THE AREA WERE SET ON
MONDAY.
LOCATION NEW HIGH TEMPERATURE OLD RECORD
GLASGOW 56 54 IN 1933
ST MARIE 54 51 IN 2002
SCOBEY 4 NW 53 50 IN 2002
WOLF POINT 53 47 IN 2002
JORDAN 59 50 IN 2001
BREDETTE 50 47 IN 1953
MALTA 59 53 IN 2002
NASHUA 57 53 IN 2002
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
955 PM CST WED JAN 11 2012
.UPDATE...DID A QUICK GRID UPDATE TO BETTER REFLECT THE CURRENT
TEMPERATURE TREND AND DECREASE LOWS BY A COUPLE DEGREES IN A FEW
SPOTS. KUEX WSR-88D STILL SHOWS A FEW FLURRIES ACROSS THE
AREA...SO DID NOT REMOVE THOSE AT THIS POINT. CLOUDS ARE ALSO A
BIT TRICKY AND KEPT THE TREND OF PARTLY CLOUDY IN THE WEST...WITH
MORE CLOUDS IN THE EAST.
&&
.PREV DISCUSSION... /ISSUED 632 PM CST WED JAN 11 2012/
UPDATE...HAVE ALLOWED THE WIND ADVISORY TO EXPIRE ON TIME AT 6
PM. THE SURFACE PRESSURE GRADIENT IS EXPECTED TO WEAKEN A LITTLE
MORE THIS EVENING...AND THAT SHOULD HELP KEEP MOST SPOTS BELOW
ADVISORY LEVELS.
PREV DISCUSSION... /ISSUED 511 PM CST WED JAN 11 2012/
AVIATION...00Z TAF. STRONG WINDS AT KGRI SHOULD SUBSIDE A LITTLE
THIS EVENING...THOUGH THEY WILL REMAIN GUSTY THROUGH THE ENTIRE
TAF PERIOD. AN ISOLATED SNOW SHOWER IS ALSO POSSIBLE EARLY IN THE
TAF PERIOD...BUT KUEX SHOWS THE MORE ORGANIZED ACTIVITY HAS MOVED
EAST OF KGRI...SO WILL LEAVE IT OUT OF THE FORECAST FOR NOW.
CEILINGS HAVE CLIMBED BACK TO VFR LEVELS...AND NAM PROXIMITY
SOUNDINGS SUGGEST THEY SHOULD GENERALLY STAY THERE. ONE QUESTION
THAT IS STILL NOT VERY CLEAR IS WILL THE VFR CEILINGS SCATTER OUT
THIS EVENING OR REMAIN IN PLACE WITH BOTH NAM AND RUC BUFR
SOUNDINGS SUGGESTING A CEILING COULD BE IN PLACE OFF AND ON
THROUGH MUCH OF THE NIGHT. WILL HOLD ONTO AT LEAST SCATTERED
CLOUDS AROUND 5KFT THROUGH THE NIGHT...BUT WOULD NOT BE SURPRISED
IF AN ADJUSTMENT BECOMES NECESSARY TO HOLD ONTO THE CEILING A BIT
LONGER.
PREV DISCUSSION... /ISSUED 411 PM CST WED JAN 11 2012/
SHORT TERM...TONIGHT AND THURSDAY.
WIND SHOULD DIMINISH JUST ENOUGH THIS EVENING TO LET THE WIND
ADVISORY END EARLY THIS EVENING. EVENING SHIFT MAY HAVE TO EXTEND
THIS ADVISORY BY A COUPLE HOURS OR SO AS GUSTS ARE A BIT STRONGER
THAN EARLIER ANTICIPATED FOR THIS TIME...BUT WILL BE A CLOSE CALL.
THE WRF SEEMS TO BE HANDLING THE FLURRY ACTIVITY THE BEST AND FOR
TONIGHT INTO THURSDAY MORNING...I EXPECT MORE FLURRY ACTIVITY ON THE
BACKSIDE OF THE MID-LEVEL LOW AS IT HEADS SOUTH ALONG THE MISSOURI
RIVER. I INCREASED TEMPERATURES TONIGHT FROM THE PREVIOUS FORECAST
CONSIDERING THE INCREASED WIND SPEEDS AND ALSO INCREASED
TEMPERATURES FOR TOMORROW A BIT DUE TO ANTICIPATED MIXING. GAGING
THE UPSTREAM DEWPOINTS AND EXPECTED MIXING...I ANTICIPATE FIRE
WEATHER ISSUES IN THE SOUTHWESTERN CWA FOR THURSDAY AFTERNOON AND
WENT WITH A RED FLAG WARNING IN THIS AREA.
LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. THE FORECAST
CONTINUES OFFICIALLY DRY THROUGH THIS TIME FRAME...ALTHOUGH ITS NOT
OUT OF THE QUESTION THAT A FLURRY OR SPRINKLE MIGHT NEED ADDED AT
SOME POINT. AS A RESULT...THE MAIN CHALLENGE WILL BE TRYING TO NAIL
DOWN A BIT OF A TEMPERATURE ROLLER COASTER AS VARIOUS MID LEVEL
WAVES/SURFACE FRONTS PASS THROUGH.
STARTING OUT AT 00Z THURSDAY EVENING...THE 12Z RUNS OF THE
NAM/ECMWF/GFS DEPICT THE CENTER OF THE 500MB CIRCULATION ASSOCIATED
WITH THE ONGOING LOW PRESSURE SYSTEM TO BE WELL OFF EAST NEAR THE
IL/IN/KY BORDER AREA...ALTHOUGH A WEAKER DISTURBANCE/NORTH-SOUTH
ZONE OF CHANNELED VORTICITY WILL DROP SOUTH TOWARD THE CENTRAL
PLAINS THROUGH THE NIGHT FROM THE NORTHERN ROCKIES...ASSOCIATED WITH
AN UPPER JET STREAK. HOWEVER...THIS FEATURE IS NOT EXPECTED TO BRING
ANYTHING MORE THAN SOME PASSING MID LEVEL CLOUDS WITH ANY FLURRY
POTENTIAL SEEMINGLY TOO LOW TO EVEN MENTION. ALTHOUGH NORTHWEST
WINDS WILL STILL BE A BIT GUSTY IN THE EVENING...SPEEDS THROUGH MOST
OF THE NIGHT WILL AVERAGE NO HIGHER THAN 10-15 MPH AS THE PRESSURE
GRADIENT CONTINUES TO RELAX. GIVEN THAT BREEZES WILL NOT DROP OFF TO
NEAR-CALM LEVELS...OPTED TO NUDGE UP LOW TEMPS 1-2 DEGREES FROM
PREVIOUS FORECAST...WITH MOST AREAS HOLDING UP IN THE 10-14 RANGE.
FRIDAY/FRIDAY NIGHT...PRONOUNCED NORTHWEST FLOW REMAINS IN PLACE IN
THE MID/UPPER LEVELS...AS THE NEXT LOW AMPLITUDE...FAST MOVING MID
LEVEL WAVE ZIPS OUT OF CANADA INTO THE EASTERN DAKOTAS/MN AREA
MAINLY FRIDAY NIGHT. ANY FLURRIES OR LIGHT SNOW ASSOCIATED WITH THIS
FEATURE SHOULD REMAIN WELL OFF TO THE NORTH FRIDAY NIGHT. GOING BACK
TO THE DAYTIME HOURS...ACTUALLY RAISED HIGHS A SOLID 4-5 DEGREES
FROM PREVIOUS FORECAST...AS FAIRLY LIGHT BUT STEADY DOWNSLOPE
WESTERLY SURFACE WINDS KICK IN ALONG WITH SOME WARM AIR ADVECTION
EVIDENT ALOFT AT 850MB. MODELS HAVE BEEN UNDER-DOING WARMING IN THIS
DOWNSLOPE PATTERN FOR WEEKS NOW GIVEN LACK OF SNOW COVER...AND THUS
HAVE HIGHS NOW BACK UP IN THE LOW-MID 40S MOST AREAS...WITH SOME
UPPER 30S NORTHEAST. BOTTOM LINE IS...WE WILL BE BACK TO
ABOVE-NORMAL READINGS ALREADY...THUS HALTING THE STREAK OF BELOW
NORMAL TEMP DAYS AT ONLY TWO. FOR LOWS FRI NIGHT...CURRENTLY HAVE
LOW 20S MOST AREAS...BUT THIS MIGHT PROVE TO BE TOO COLD AS WESTERLY
BREEZES COULD EVEN INDUCE RISING TEMPERATURES OVERNIGHT. GIVEN THIS
IS STILL 5 PERIODS OUT WILL JUST STICK WITH THE STANDARD DIURNAL
TEMP DROP-OFF FOR NOW.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT BECOMES MORE WESTERLY
VERSUS NORTHERLY AS BROAD...LOW AMPLITUDE MID LEVEL RIDGING AND
HEIGHT RISES OVERSPREAD THE PLAINS...DOWNSTREAM FROM THE NEXT WAVE
COMING INTO THE PACIFIC NORTHWEST. WITH A SIMILAR DOWNSLOPE SURFACE
WIND COMPONENT TO FRIDAY...AGAIN FELT JUSTIFIED RAISING HIGH TEMPS
AROUND 3 DEGREES FROM PREVIOUS...NOW PUTTING MOST AREAS INTO THE
45-50 RANGE AND EVEN LOW 50S SOUTHWEST. AS WITH FRIDAY NIGHT...TEMPS
SATURDAY NIGHT COULD BE STEADY TO EVEN SLOWLY RISING GIVEN
INCREASING SOUTHERLY WINDS...BUT FOR NOW WILL STICK CLOSE TO
GUIDANCE LOWS IN THE LOW-MID 20S...WHICH COULD AGAIN ULTIMATELY
PROVE TO BE TOO COLD.
SUNDAY/SUNDAY NIGHT...THIS IS STILL LOOKING LIKE THE WARMEST DAY OF
THE FORECAST PERIOD...AS BOTH THE ECMWF/GFS SHOW 850MB TEMPS RISING
INTO THE +5-10C RANGE AS SOUTHERLY BREEZES INCREASE IN RESPONSE TO
PRESSURE FALLS FROM THE INCOMING NORTHWEST CONUS SHORTWAVE. CHANGED
HIGHS LITTLE FROM PREVIOUS FORECAST...WHICH WERE ALREADY WELL ABOVE
MEX GUIDANCE NUMBERS...WITH LOW-MID 50S CWA-WIDE. SUNDAY NIGHT...NOT
ONLY DOES THE NORTHWEST CONUS TROUGH APPROACH THE REGION...BUT A
SOUTHERN STREAM WAVE ALSO ZIPS EAST TOWARD KS/OK. ANY LIGHT PRECIP
IN THE CENTRAL CONUS SUNDAY NIGHT SHOULD REMAIN WELL OFF TO THE
NORTHWEST AND SOUTHEAST OF THE CWA.
MONDAY/MONDAY NIGHT...THE PRIMARY SHORTWAVE PASSES EAST ACROSS THE
REGION...ALLOWING A SURFACE COLD FRONT TO PUSH SOUTH ACROSS THE
REGION. LATEST MODELS ARE NOW IN BETTER AGREEMENT THAT THIS FRONT
WILL COME THROUGH DURING THE DAY MONDAY...ALTHOUGH AT THIS POINT
WINDS DO NOT APPEAR TO BE NEARLY AS STRONG AS THOSE WITH TODAY/S
FRONT. TEMPERATURE WISE...KEPT HIGHS IN THE 40S MOST AREAS...BUT IF
THIS FRONT MOVES IN FASTER A LOWERING TREND MORE SO INTO THE 30S MAY
PROVE NECESSARY. PRECIP CHANCES APPEAR RATHER LOW WITH THIS
SYSTEM...AS THE MAIN MOISTURE TAP FOCUSES PRECIPITATION FROM IA/MO
AND POINTS EAST. SOMETHING TO WATCH THOUGH.
TUESDAY INTO WEDNESDAY...BROAD RIDGING AGAIN RE-ESTABLISHES ITSELF
ACROSS THE REGION IN WEST-NORTHWEST FLOW ALOFT...KEEPING THE NEXT
COLD SNAP BRIEF AS WELL. DESPITE THE PASSING COLD FRONT...ACTUALLY
RAISED TUESDAY HIGHS MAINLY INTO THE 31-36 RANGE. FOR
WEDNESDAY...WENT WITH ALLBLEND CONSENSUS FOR HIGHS WITH LOW-MID
40S...BUT IF THE SYNOPTIC PATTERN HOLDS IN FUTURE MODEL RUNS WOULD
NOT BE SURPRISED TO SEE THESE HIGHS ULTIMATELY CLIMB INTO THE UPPER
40S OR EVEN 50S. LOOKING OUT THROUGH ROUGHLY JAN 20TH...IT APPEARS
NEB/KS WILL REMAIN ON THE WARM SIDE OF A RATHER TIGHT 850MB TEMP
GRADIENT STRETCHED ACROSS THE NORTHERN PLAINS STATES...AS THE TRULY
COLD AIR REMAINS LARGELY BOTTLED UP INTO CANADA TO THE NORTH OF THE
UPPER JET AXIS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING FROM NOON TO 6 PM CST THURSDAY FOR NEZ060-072-
073-082>084.
KS...RED FLAG WARNING FROM NOON TO 6 PM CST THURSDAY FOR KSZ005-006-
017-018.
&&
$$
UPDATE/AVIATION...KING
SHORT TERM...HEINLEIN
LONG TERM...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
632 PM CST WED JAN 11 2012
.UPDATE...HAVE ALLOWED THE WIND ADVISORY TO EXPIRE ON TIME AT 6
PM. THE SURFACE PRESSURE GRADIENT IS EXPECTED TO WEAKEN A LITTLE
MORE THIS EVENING...AND THAT SHOULD HELP KEEP MOST SPOTS BELOW
ADVISORY LEVELS.
&&
.PREV DISCUSSION... /ISSUED 511 PM CST WED JAN 11 2012/
AVIATION...00Z TAF. STRONG WINDS AT KGRI SHOULD SUBSIDE A LITTLE
THIS EVENING...THOUGH THEY WILL REMAIN GUSTY THROUGH THE ENTIRE
TAF PERIOD. AN ISOLATED SNOW SHOWER IS ALSO POSSIBLE EARLY IN THE
TAF PERIOD...BUT KUEX SHOWS THE MORE ORGANIZED ACTIVITY HAS MOVED
EAST OF KGRI...SO WILL LEAVE IT OUT OF THE FORECAST FOR NOW.
CEILINGS HAVE CLIMBED BACK TO VFR LEVELS...AND NAM PROXIMITY
SOUNDINGS SUGGEST THEY SHOULD GENERALLY STAY THERE. ONE QUESTION
THAT IS STILL NOT VERY CLEAR IS WILL THE VFR CEILINGS SCATTER OUT
THIS EVENING OR REMAIN IN PLACE WITH BOTH NAM AND RUC BUFR
SOUNDINGS SUGGESTING A CEILING COULD BE IN PLACE OFF AND ON
THROUGH MUCH OF THE NIGHT. WILL HOLD ONTO AT LEAST SCATTERED
CLOUDS AROUND 5KFT THROUGH THE NIGHT...BUT WOULD NOT BE SURPRISED
IF AN ADJUSTMENT BECOMES NECESSARY TO HOLD ONTO THE CEILING A BIT
LONGER.
PREV DISCUSSION... /ISSUED 411 PM CST WED JAN 11 2012/
SHORT TERM...TONIGHT AND THURSDAY.
WIND SHOULD DIMINISH JUST ENOUGH THIS EVENING TO LET THE WIND
ADVISORY END EARLY THIS EVENING. EVENING SHIFT MAY HAVE TO EXTEND
THIS ADVISORY BY A COUPLE HOURS OR SO AS GUSTS ARE A BIT STRONGER
THAN EARLIER ANTICIPATED FOR THIS TIME...BUT WILL BE A CLOSE CALL.
THE WRF SEEMS TO BE HANDLING THE FLURRY ACTIVITY THE BEST AND FOR
TONIGHT INTO THURSDAY MORNING...I EXPECT MORE FLURRY ACTIVITY ON THE
BACKSIDE OF THE MID-LEVEL LOW AS IT HEADS SOUTH ALONG THE MISSOURI
RIVER. I INCREASED TEMPERATURES TONIGHT FROM THE PREVIOUS FORECAST
CONSIDERING THE INCREASED WIND SPEEDS AND ALSO INCREASED
TEMPERATURES FOR TOMORROW A BIT DUE TO ANTICIPATED MIXING. GAGING
THE UPSTREAM DEWPOINTS AND EXPECTED MIXING...I ANTICIPATE FIRE
WEATHER ISSUES IN THE SOUTHWESTERN CWA FOR THURSDAY AFTERNOON AND
WENT WITH A RED FLAG WARNING IN THIS AREA.
LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. THE FORECAST
CONTINUES OFFICIALLY DRY THROUGH THIS TIME FRAME...ALTHOUGH ITS NOT
OUT OF THE QUESTION THAT A FLURRY OR SPRINKLE MIGHT NEED ADDED AT
SOME POINT. AS A RESULT...THE MAIN CHALLENGE WILL BE TRYING TO NAIL
DOWN A BIT OF A TEMPERATURE ROLLER COASTER AS VARIOUS MID LEVEL
WAVES/SURFACE FRONTS PASS THROUGH.
STARTING OUT AT 00Z THURSDAY EVENING...THE 12Z RUNS OF THE
NAM/ECMWF/GFS DEPICT THE CENTER OF THE 500MB CIRCULATION ASSOCIATED
WITH THE ONGOING LOW PRESSURE SYSTEM TO BE WELL OFF EAST NEAR THE
IL/IN/KY BORDER AREA...ALTHOUGH A WEAKER DISTURBANCE/NORTH-SOUTH
ZONE OF CHANNELED VORTICITY WILL DROP SOUTH TOWARD THE CENTRAL
PLAINS THROUGH THE NIGHT FROM THE NORTHERN ROCKIES...ASSOCIATED WITH
AN UPPER JET STREAK. HOWEVER...THIS FEATURE IS NOT EXPECTED TO BRING
ANYTHING MORE THAN SOME PASSING MID LEVEL CLOUDS WITH ANY FLURRY
POTENTIAL SEEMINGLY TOO LOW TO EVEN MENTION. ALTHOUGH NORTHWEST
WINDS WILL STILL BE A BIT GUSTY IN THE EVENING...SPEEDS THROUGH MOST
OF THE NIGHT WILL AVERAGE NO HIGHER THAN 10-15 MPH AS THE PRESSURE
GRADIENT CONTINUES TO RELAX. GIVEN THAT BREEZES WILL NOT DROP OFF TO
NEAR-CALM LEVELS...OPTED TO NUDGE UP LOW TEMPS 1-2 DEGREES FROM
PREVIOUS FORECAST...WITH MOST AREAS HOLDING UP IN THE 10-14 RANGE.
FRIDAY/FRIDAY NIGHT...PRONOUNCED NORTHWEST FLOW REMAINS IN PLACE IN
THE MID/UPPER LEVELS...AS THE NEXT LOW AMPLITUDE...FAST MOVING MID
LEVEL WAVE ZIPS OUT OF CANADA INTO THE EASTERN DAKOTAS/MN AREA
MAINLY FRIDAY NIGHT. ANY FLURRIES OR LIGHT SNOW ASSOCIATED WITH THIS
FEATURE SHOULD REMAIN WELL OFF TO THE NORTH FRIDAY NIGHT. GOING BACK
TO THE DAYTIME HOURS...ACTUALLY RAISED HIGHS A SOLID 4-5 DEGREES
FROM PREVIOUS FORECAST...AS FAIRLY LIGHT BUT STEADY DOWNSLOPE
WESTERLY SURFACE WINDS KICK IN ALONG WITH SOME WARM AIR ADVECTION
EVIDENT ALOFT AT 850MB. MODELS HAVE BEEN UNDER-DOING WARMING IN THIS
DOWNSLOPE PATTERN FOR WEEKS NOW GIVEN LACK OF SNOW COVER...AND THUS
HAVE HIGHS NOW BACK UP IN THE LOW-MID 40S MOST AREAS...WITH SOME
UPPER 30S NORTHEAST. BOTTOM LINE IS...WE WILL BE BACK TO
ABOVE-NORMAL READINGS ALREADY...THUS HALTING THE STREAK OF BELOW
NORMAL TEMP DAYS AT ONLY TWO. FOR LOWS FRI NIGHT...CURRENTLY HAVE
LOW 20S MOST AREAS...BUT THIS MIGHT PROVE TO BE TOO COLD AS WESTERLY
BREEZES COULD EVEN INDUCE RISING TEMPERATURES OVERNIGHT. GIVEN THIS
IS STILL 5 PERIODS OUT WILL JUST STICK WITH THE STANDARD DIURNAL
TEMP DROP-OFF FOR NOW.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT BECOMES MORE WESTERLY
VERSUS NORTHERLY AS BROAD...LOW AMPLITUDE MID LEVEL RIDGING AND
HEIGHT RISES OVERSPREAD THE PLAINS...DOWNSTREAM FROM THE NEXT WAVE
COMING INTO THE PACIFIC NORTHWEST. WITH A SIMILAR DOWNSLOPE SURFACE
WIND COMPONENT TO FRIDAY...AGAIN FELT JUSTIFIED RAISING HIGH TEMPS
AROUND 3 DEGREES FROM PREVIOUS...NOW PUTTING MOST AREAS INTO THE
45-50 RANGE AND EVEN LOW 50S SOUTHWEST. AS WITH FRIDAY NIGHT...TEMPS
SATURDAY NIGHT COULD BE STEADY TO EVEN SLOWLY RISING GIVEN
INCREASING SOUTHERLY WINDS...BUT FOR NOW WILL STICK CLOSE TO
GUIDANCE LOWS IN THE LOW-MID 20S...WHICH COULD AGAIN ULTIMATELY
PROVE TO BE TOO COLD.
SUNDAY/SUNDAY NIGHT...THIS IS STILL LOOKING LIKE THE WARMEST DAY OF
THE FORECAST PERIOD...AS BOTH THE ECMWF/GFS SHOW 850MB TEMPS RISING
INTO THE +5-10C RANGE AS SOUTHERLY BREEZES INCREASE IN RESPONSE TO
PRESSURE FALLS FROM THE INCOMING NORTHWEST CONUS SHORTWAVE. CHANGED
HIGHS LITTLE FROM PREVIOUS FORECAST...WHICH WERE ALREADY WELL ABOVE
MEX GUIDANCE NUMBERS...WITH LOW-MID 50S CWA-WIDE. SUNDAY NIGHT...NOT
ONLY DOES THE NORTHWEST CONUS TROUGH APPROACH THE REGION...BUT A
SOUTHERN STREAM WAVE ALSO ZIPS EAST TOWARD KS/OK. ANY LIGHT PRECIP
IN THE CENTRAL CONUS SUNDAY NIGHT SHOULD REMAIN WELL OFF TO THE
NORTHWEST AND SOUTHEAST OF THE CWA.
MONDAY/MONDAY NIGHT...THE PRIMARY SHORTWAVE PASSES EAST ACROSS THE
REGION...ALLOWING A SURFACE COLD FRONT TO PUSH SOUTH ACROSS THE
REGION. LATEST MODELS ARE NOW IN BETTER AGREEMENT THAT THIS FRONT
WILL COME THROUGH DURING THE DAY MONDAY...ALTHOUGH AT THIS POINT
WINDS DO NOT APPEAR TO BE NEARLY AS STRONG AS THOSE WITH TODAY/S
FRONT. TEMPERATURE WISE...KEPT HIGHS IN THE 40S MOST AREAS...BUT IF
THIS FRONT MOVES IN FASTER A LOWERING TREND MORE SO INTO THE 30S MAY
PROVE NECESSARY. PRECIP CHANCES APPEAR RATHER LOW WITH THIS
SYSTEM...AS THE MAIN MOISTURE TAP FOCUSES PRECIPITATION FROM IA/MO
AND POINTS EAST. SOMETHING TO WATCH THOUGH.
TUESDAY INTO WEDNESDAY...BROAD RIDGING AGAIN RE-ESTABLISHES ITSELF
ACROSS THE REGION IN WEST-NORTHWEST FLOW ALOFT...KEEPING THE NEXT
COLD SNAP BRIEF AS WELL. DESPITE THE PASSING COLD FRONT...ACTUALLY
RAISED TUESDAY HIGHS MAINLY INTO THE 31-36 RANGE. FOR
WEDNESDAY...WENT WITH ALLBLEND CONSENSUS FOR HIGHS WITH LOW-MID
40S...BUT IF THE SYNOPTIC PATTERN HOLDS IN FUTURE MODEL RUNS WOULD
NOT BE SURPRISED TO SEE THESE HIGHS ULTIMATELY CLIMB INTO THE UPPER
40S OR EVEN 50S. LOOKING OUT THROUGH ROUGHLY JAN 20TH...IT APPEARS
NEB/KS WILL REMAIN ON THE WARM SIDE OF A RATHER TIGHT 850MB TEMP
GRADIENT STRETCHED ACROSS THE NORTHERN PLAINS STATES...AS THE TRULY
COLD AIR REMAINS LARGELY BOTTLED UP INTO CANADA TO THE NORTH OF THE
UPPER JET AXIS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING FROM NOON TO 6 PM CST THURSDAY FOR NEZ060-072-
073-082>084.
KS...RED FLAG WARNING FROM NOON TO 6 PM CST THURSDAY FOR KSZ005-006-
017-018.
&&
$$
UPDATE/AVIATION...KING
SHORT TERM...HEINLEIN
LONG TERM...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
511 PM CST WED JAN 11 2012
.AVIATION...00Z TAF. STRONG WINDS AT KGRI SHOULD SUBSIDE A LITTLE
THIS EVENING...THOUGH THEY WILL REMAIN GUSTY THROUGH THE ENTIRE
TAF PERIOD. AN ISOLATED SNOW SHOWER IS ALSO POSSIBLE EARLY IN THE
TAF PERIOD...BUT KUEX SHOWS THE MORE ORGANIZED ACTIVITY HAS MOVED
EAST OF KGRI...SO WILL LEAVE IT OUT OF THE FORECAST FOR NOW.
CEILINGS HAVE CLIMBED BACK TO VFR LEVELS...AND NAM PROXIMITY
SOUNDINGS SUGGEST THEY SHOULD GENERALLY STAY THERE. ONE QUESTION
THAT IS STILL NOT VERY CLEAR IS WILL THE VFR CEILINGS SCATTER OUT
THIS EVENING OR REMAIN IN PLACE WITH BOTH NAM AND RUC BUFR
SOUNDINGS SUGGESTING A CEILING COULD BE IN PLACE OFF AND ON
THROUGH MUCH OF THE NIGHT. WILL HOLD ONTO AT LEAST SCATTERED
CLOUDS AROUND 5KFT THROUGH THE NIGHT...BUT WOULD NOT BE SURPRISED
IF AN ADJUSTMENT BECOMES NECESSARY TO HOLD ONTO THE CEILING A BIT
LONGER.
&&
.PREV DISCUSSION... /ISSUED 411 PM CST WED JAN 11 2012/
SHORT TERM...TONIGHT AND THURSDAY.
WIND SHOULD DIMINISH JUST ENOUGH THIS EVENING TO LET THE WIND
ADVISORY END EARLY THIS EVENING. EVENING SHIFT MAY HAVE TO EXTEND
THIS ADVISORY BY A COUPLE HOURS OR SO AS GUSTS ARE A BIT STRONGER
THAN EARLIER ANTICIPATED FOR THIS TIME...BUT WILL BE A CLOSE CALL.
THE WRF SEEMS TO BE HANDLING THE FLURRY ACTIVITY THE BEST AND FOR
TONIGHT INTO THURSDAY MORNING...I EXPECT MORE FLURRY ACTIVITY ON THE
BACKSIDE OF THE MID-LEVEL LOW AS IT HEADS SOUTH ALONG THE MISSOURI
RIVER. I INCREASED TEMPERATURES TONIGHT FROM THE PREVIOUS FORECAST
CONSIDERING THE INCREASED WIND SPEEDS AND ALSO INCREASED
TEMPERATURES FOR TOMORROW A BIT DUE TO ANTICIPATED MIXING. GAGING
THE UPSTREAM DEWPOINTS AND EXPECTED MIXING...I ANTICIPATE FIRE
WEATHER ISSUES IN THE SOUTHWESTERN CWA FOR THURSDAY AFTERNOON AND
WENT WITH A RED FLAG WARNING IN THIS AREA.
LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. THE FORECAST
CONTINUES OFFICIALLY DRY THROUGH THIS TIME FRAME...ALTHOUGH ITS NOT
OUT OF THE QUESTION THAT A FLURRY OR SPRINKLE MIGHT NEED ADDED AT
SOME POINT. AS A RESULT...THE MAIN CHALLENGE WILL BE TRYING TO NAIL
DOWN A BIT OF A TEMPERATURE ROLLER COASTER AS VARIOUS MID LEVEL
WAVES/SURFACE FRONTS PASS THROUGH.
STARTING OUT AT 00Z THURSDAY EVENING...THE 12Z RUNS OF THE
NAM/ECMWF/GFS DEPICT THE CENTER OF THE 500MB CIRCULATION ASSOCIATED
WITH THE ONGOING LOW PRESSURE SYSTEM TO BE WELL OFF EAST NEAR THE
IL/IN/KY BORDER AREA...ALTHOUGH A WEAKER DISTURBANCE/NORTH-SOUTH
ZONE OF CHANNELED VORTICITY WILL DROP SOUTH TOWARD THE CENTRAL
PLAINS THROUGH THE NIGHT FROM THE NORTHERN ROCKIES...ASSOCIATED WITH
AN UPPER JET STREAK. HOWEVER...THIS FEATURE IS NOT EXPECTED TO BRING
ANYTHING MORE THAN SOME PASSING MID LEVEL CLOUDS WITH ANY FLURRY
POTENTIAL SEEMINGLY TOO LOW TO EVEN MENTION. ALTHOUGH NORTHWEST
WINDS WILL STILL BE A BIT GUSTY IN THE EVENING...SPEEDS THROUGH MOST
OF THE NIGHT WILL AVERAGE NO HIGHER THAN 10-15 MPH AS THE PRESSURE
GRADIENT CONTINUES TO RELAX. GIVEN THAT BREEZES WILL NOT DROP OFF TO
NEAR-CALM LEVELS...OPTED TO NUDGE UP LOW TEMPS 1-2 DEGREES FROM
PREVIOUS FORECAST...WITH MOST AREAS HOLDING UP IN THE 10-14 RANGE.
FRIDAY/FRIDAY NIGHT...PRONOUNCED NORTHWEST FLOW REMAINS IN PLACE IN
THE MID/UPPER LEVELS...AS THE NEXT LOW AMPLITUDE...FAST MOVING MID
LEVEL WAVE ZIPS OUT OF CANADA INTO THE EASTERN DAKOTAS/MN AREA
MAINLY FRIDAY NIGHT. ANY FLURRIES OR LIGHT SNOW ASSOCIATED WITH THIS
FEATURE SHOULD REMAIN WELL OFF TO THE NORTH FRIDAY NIGHT. GOING BACK
TO THE DAYTIME HOURS...ACTUALLY RAISED HIGHS A SOLID 4-5 DEGREES
FROM PREVIOUS FORECAST...AS FAIRLY LIGHT BUT STEADY DOWNSLOPE
WESTERLY SURFACE WINDS KICK IN ALONG WITH SOME WARM AIR ADVECTION
EVIDENT ALOFT AT 850MB. MODELS HAVE BEEN UNDER-DOING WARMING IN THIS
DOWNSLOPE PATTERN FOR WEEKS NOW GIVEN LACK OF SNOW COVER...AND THUS
HAVE HIGHS NOW BACK UP IN THE LOW-MID 40S MOST AREAS...WITH SOME
UPPER 30S NORTHEAST. BOTTOM LINE IS...WE WILL BE BACK TO
ABOVE-NORMAL READINGS ALREADY...THUS HALTING THE STREAK OF BELOW
NORMAL TEMP DAYS AT ONLY TWO. FOR LOWS FRI NIGHT...CURRENTLY HAVE
LOW 20S MOST AREAS...BUT THIS MIGHT PROVE TO BE TOO COLD AS WESTERLY
BREEZES COULD EVEN INDUCE RISING TEMPERATURES OVERNIGHT. GIVEN THIS
IS STILL 5 PERIODS OUT WILL JUST STICK WITH THE STANDARD DIURNAL
TEMP DROP-OFF FOR NOW.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT BECOMES MORE WESTERLY
VERSUS NORTHERLY AS BROAD...LOW AMPLITUDE MID LEVEL RIDGING AND
HEIGHT RISES OVERSPREAD THE PLAINS...DOWNSTREAM FROM THE NEXT WAVE
COMING INTO THE PACIFIC NORTHWEST. WITH A SIMILAR DOWNSLOPE SURFACE
WIND COMPONENT TO FRIDAY...AGAIN FELT JUSTIFIED RAISING HIGH TEMPS
AROUND 3 DEGREES FROM PREVIOUS...NOW PUTTING MOST AREAS INTO THE
45-50 RANGE AND EVEN LOW 50S SOUTHWEST. AS WITH FRIDAY NIGHT...TEMPS
SATURDAY NIGHT COULD BE STEADY TO EVEN SLOWLY RISING GIVEN
INCREASING SOUTHERLY WINDS...BUT FOR NOW WILL STICK CLOSE TO
GUIDANCE LOWS IN THE LOW-MID 20S...WHICH COULD AGAIN ULTIMATELY
PROVE TO BE TOO COLD.
SUNDAY/SUNDAY NIGHT...THIS IS STILL LOOKING LIKE THE WARMEST DAY OF
THE FORECAST PERIOD...AS BOTH THE ECMWF/GFS SHOW 850MB TEMPS RISING
INTO THE +5-10C RANGE AS SOUTHERLY BREEZES INCREASE IN RESPONSE TO
PRESSURE FALLS FROM THE INCOMING NORTHWEST CONUS SHORTWAVE. CHANGED
HIGHS LITTLE FROM PREVIOUS FORECAST...WHICH WERE ALREADY WELL ABOVE
MEX GUIDANCE NUMBERS...WITH LOW-MID 50S CWA-WIDE. SUNDAY NIGHT...NOT
ONLY DOES THE NORTHWEST CONUS TROUGH APPROACH THE REGION...BUT A
SOUTHERN STREAM WAVE ALSO ZIPS EAST TOWARD KS/OK. ANY LIGHT PRECIP
IN THE CENTRAL CONUS SUNDAY NIGHT SHOULD REMAIN WELL OFF TO THE
NORTHWEST AND SOUTHEAST OF THE CWA.
MONDAY/MONDAY NIGHT...THE PRIMARY SHORTWAVE PASSES EAST ACROSS THE
REGION...ALLOWING A SURFACE COLD FRONT TO PUSH SOUTH ACROSS THE
REGION. LATEST MODELS ARE NOW IN BETTER AGREEMENT THAT THIS FRONT
WILL COME THROUGH DURING THE DAY MONDAY...ALTHOUGH AT THIS POINT
WINDS DO NOT APPEAR TO BE NEARLY AS STRONG AS THOSE WITH TODAY/S
FRONT. TEMPERATURE WISE...KEPT HIGHS IN THE 40S MOST AREAS...BUT IF
THIS FRONT MOVES IN FASTER A LOWERING TREND MORE SO INTO THE 30S MAY
PROVE NECESSARY. PRECIP CHANCES APPEAR RATHER LOW WITH THIS
SYSTEM...AS THE MAIN MOISTURE TAP FOCUSES PRECIPITATION FROM IA/MO
AND POINTS EAST. SOMETHING TO WATCH THOUGH.
TUESDAY INTO WEDNESDAY...BROAD RIDGING AGAIN RE-ESTABLISHES ITSELF
ACROSS THE REGION IN WEST-NORTHWEST FLOW ALOFT...KEEPING THE NEXT
COLD SNAP BRIEF AS WELL. DESPITE THE PASSING COLD FRONT...ACTUALLY
RAISED TUESDAY HIGHS MAINLY INTO THE 31-36 RANGE. FOR
WEDNESDAY...WENT WITH ALLBLEND CONSENSUS FOR HIGHS WITH LOW-MID
40S...BUT IF THE SYNOPTIC PATTERN HOLDS IN FUTURE MODEL RUNS WOULD
NOT BE SURPRISED TO SEE THESE HIGHS ULTIMATELY CLIMB INTO THE UPPER
40S OR EVEN 50S. LOOKING OUT THROUGH ROUGHLY JAN 20TH...IT APPEARS
NEB/KS WILL REMAIN ON THE WARM SIDE OF A RATHER TIGHT 850MB TEMP
GRADIENT STRETCHED ACROSS THE NORTHERN PLAINS STATES...AS THE TRULY
COLD AIR REMAINS LARGELY BOTTLED UP INTO CANADA TO THE NORTH OF THE
UPPER JET AXIS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
060>064-072>077-082>087.
RED FLAG WARNING FROM NOON TO 6 PM CST THURSDAY FOR NEZ060-072-
073-082>084.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-017>019.
RED FLAG WARNING FROM NOON TO 6 PM CST THURSDAY FOR KSZ005-006-
017-018.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...PFANNKUCH
AVIATION...KING
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1052 PM EST WED JAN 11 2012
.SYNOPSIS...
A STORM SYSTEM WILL BRING PRECIPITATION TONIGHT INTO THURSDAY.
EAST OF INTERSTATE 81...ESPECIALLY AT HIGHER ELEVATIONS...THE
PRECIPITATION MAY BEGIN AS A WINTRY MIX OF FREEZING
RAIN...SLEET...AND SNOW. THE REMAINDER OF THE REGION WILL
GENERALLY HAVE JUST A COLD RAIN. HOWEVER...A COLD FRONT WILL SWEEP
THROUGH LATE THURSDAY NIGHT INTO FRIDAY MORNING...RESULTING IN
SNOW SHOWERS DURING THE DAY FRIDAY. COURTESY OF LAKE EFFECT...SNOW
SHOWERS CONTINUE INTO SATURDAY FOR MUCH OF THE REGION.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
1030 PM UPDATE...NO CHANGES TO THE PREVIOUS FORECAST. UPDATE
EARLIER TO REMOVE SNOWFALL AMOUNTS LOOKS TO BE ON TRACK WITH JUST
A FEW REPORTS OF A FEW FLAKES AT THE ONSET. WE ARE MOSTLY SEEING SLEET
OR RAIN...WITH SOME POCKETS OF FREEZING RAIN. AS THE
PRECIPITATION MOVES FARTHER NORTH AND EAST AND ENCOUNTERS SOME
COLDER SURFACE TEMPS AND LOWER DEWPOINTS...FREEZING RAIN WILL
BECOME MORE LIKELY AND THE ADVISORY CURRENTLY IN PLACE COVERS
THIS. I WAS TEMPTED TO DROP MADISON...CHENANGO...PIKE...AND WAYNE
COUNTIES FROM THE ADVISORY WITH MOST MESONET SITES SHOWING TEMPS
IN THE MID 30S. DECIDED TO HOLD OFF BECAUSE WE HAVE GOTTEN A FEW
REPORTS OF FREEZING RAIN BUT THEY HAVE BEEN CONFINED TO ELEVATIONS
CLOSER TO 2000 FEET IN THESE AREAS. WITH THE UPDATE TO THE
ADVISORY...TRIED TO STRESS HIGHER ELEVATIONS HERE FOR THE FREEZING
RAIN POTENTIAL.
FARTHER NORTH AND EAST IN OUR NORMALLY COLDER SPOTS OF
ONEIDA...OTSEGO...DELAWARE AND SULLIVAN COUNTIES...FREEZING RAIN
POTENTIAL IS MUCH HIGHER AND I REMOVED ANY HIGHER ELEVATION
WORDING BECAUSE IT WILL BE MORE WIDESPREAD HERE AND NOT JUST
CONFINED TO THE HIGHEST TERRAIN. A GOOD EXAMPLE IS MONTICELLO
WHICH HAS DROPPED FROM 36 TO 32 AND IS PROBABLY SEEING SOME
FREEZING RAIN ATTM. THE PREVIOUS AFD IS BELOW...
730 PM
UPDATE...OVERALL FORECAST EVOLUTION IS IN GOOD SHAPE.
PRECIPITATION IS ADVANCING ACROSS THE SOUTHERN THIRD OF THE CWA AS
WE SPEAK. PREFER THE NAM/RUC FORECAST SOUNDINGS WHICH SHOW THE
PRECIPITATION STARTING OFF MOSTLY AS ALL RAIN IN THE LOWER
ELEVATIONS...WITH A MIX OF ANYTHING FROM RAIN TO SLEET OR EVEN A
FEW SNOWFLAKES ABOVE 1200 FEET. TAMDAR SOUNDINGS OUT OF SYRACUSE
SHOW THIS NICELY WITH PLENTY OF DRY AIR IN THE MID LEVELS ALLOWING
FOR SOME QUICK WET BULBING...BEFORE OUR WARM NOSE PUNCHES IN
AROUND 850 MB. THIS PUNCH OF WARMER AIR WILL TRANSITION MOST OF
THE AREA TO PLAIN RAIN. THE EXCEPTION WILL BE FARTHER EAST AND
NORTH...WHERE WE HAD ADVISORIES IN PLACE...WHERE THE MIX OF
SLEET/SNOW...AND EVEN SOME FREEZING RAIN WILL LINGER MUCH LONGER.
MAIN ADJUSTMENT TO THIS PACKAGE IS TO LOWER SNOWFALL AMOUNTS.
WHILE SOME SNOW IS POSSIBLE NEAR THE ONSET AND SHORTLY
THEREAFTER...FEEL THE WARM NOSE DEPICTED ON THE RUC AND NAM WILL
BE ENOUGH TO HELP US MIX WITH SLEET QUICKLY...THUS CUTTING DOWN
SNOWFALL AMOUNTS. AT THIS POINT SEE NOTHING MORE THAN A COATING OF
SNOWFALL OVER THE FAR EAST...WITH OUR ADVISORIES JUSTIFIED BY A
COMINBATION OF SLEET AND ESPECIALLY FREEZING RAIN.
AFTER 07Z ENOUGH WARM AIR ALOFT WILL MOVE INTO THE AREA THAT IT
WILL BE JUST A RAIN OR FREEZING RAIN SITUATION...WITH ALL THE
EMPHASIS SHIFTING TO OUR SURFACE TEMPS. OUR NORMALLY COLDER SPOTS
FROM NORTHERN OTSEGO COUNTY INTO THE MOHAWK VALLEY REMAIN AT THE
HIGHEST RISK FOR A PROLONGED PERIOD OF LIGHT FREEZING RAIN. THIS
IS WELL SUPPORTED BY OBS IN THE CENTRAL MOHAWK VALLEY THAT ARE
ALREADY BELOW FREEZING...WITH DEW-POINTS IN THE LOWER TO MIDDLE
20S.
LOOK FOR OUR NEXT UPDATE AROUND 10 PM. IF WE CONTINUE TO SEE TEMPS
ABOVE FREEZING IN NORTHERN PA...WE MAY BE ABLE TO TRIM BACK OUR
ADVISORY FROM SOUTH TO NORTH.
415 PM
UPDATE...TREND FOR A WARMER INCIPIENT BOUNDARY LAYER CONTINUES IN
THE MODELS...AS SYSTEM MOVES IN TONIGHT. THUS I DO NOT SEE A NEED
FOR ANY FURTHER EXPANSION OF CURRENT WINTER WEATHER
ADVISORY...WHICH INCLUDES COUNTIES EAST OF INTERSTATE 81. FOR
COUNTIES ALONG AND WEST OF INTERSTATE 81...HIGH CONFIDENCE NOW
THAT PRECIPITATION TYPE WILL BE ALL RAIN...WITH PERHAPS ONLY A
LITTLE BRIEF SLEET BUT WITH TEMPERATURES STAYING ABOVE FREEZING.
AND OF THE WINTER WEATHER ADVISORY COUNTIES...TRANSITION TO PLAIN
RAIN WILL OCCUR EARLY FOR ALL BUT ONEIDA/DELAWARE/OTSEGO...SO I
MOVED UP THE END TIME FOR THOSE ZONES TO 6 AM. FOR THE EARLIER
ENDING ZONES...ICE AND SNOW ACCUMULATIONS LOOK TO BE FAIRLY LIGHT
AND MAINLY AT HIGHER ELEVATIONS. MANY VALLEY LOCATIONS MAY GET
THROUGH WITH ONLY PLAIN RAIN OR A LITTLE LIGHT SLEET.
COLD AIR WILL LINGER LONGER IN THE NORTHEASTERN ZONES COURTESY OF
COLD AIR DAMMING...SO WINTRY MIX WILL LAST INTO THE MORNING. WE
WILL HAVE TO WATCH CLOSELY FOR ICE ACCUMULATIONS IN EXCESS OF A
QUARTER INCH...IN PARTICULAR TOWARDS THE MOHAWK VALLEY/SOUTHERN
TUG HILL PLATEAU...SHOULD THE COLD AIR TAKE LONG TO SCOUR OUT.
SNOW ACCUMULATIONS MEANWHILE WILL BE OF HIGH WATER
CONTENT...GENERALLY 1 TO 3 INCHES AND MAINLY AT HIGHER ELEVATIONS.
WHATEVER THE TYPE...FOR THE AREA IN GENERAL RAW PRECIPITATION
AMOUNTS WILL RANGE FROM A HALF INCH OR SO IN THE WEST-
NORTHWEST...TO ALMOST AN INCH IN THE SOUTHEAST. AFTER A BRIEF DIP
IN TEMPERATURES EARLY THIS EVENING...LOOKING FOR STEADY TO
SLOWLY RISING TEMPERATURES OVERNIGHT. FINGER LAKES...SOUTHERN
TIER OF NY...AND MOST OF NORTHEAST PA WILL EVENTUALLY GET INTO
THE 40S THURSDAY.
DEEPER MOISTURE EXITS WITH THE OCCLUDED FRONT MIDDAY
THURSDAY...LEAVING LIGHT SHOWERS OR PERHAPS DRIZZLE IN THE
AFTERNOON TO EVENING. BOUNDARY LAYER WILL BE SLOW TO COOL THURSDAY
NIGHT...UNTIL ARRIVAL OF STRONG NEGATIVELY TILTED COLD FRONT
TOWARDS DAWN FRIDAY. SO CHANGEOVER OF ANY REMAINING LIGHT RAIN
SHOWERS TO SNOW...WILL BE GRADUAL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
UPDATED AS OF 4 PM WED... MODEL CONSENSUS IS FAIRLY GOOD ON SYSTEM
EVOLUTION THIS PD.
A STG COLD FRONT IS SLATED TO CROSS THE FA FROM SW TO NE FRI
AM...GENERALLY IN THE 12-15Z TIME FRAME. QG FORCING IS PRETTY POTENT
WITH THIS FRNT...AS A HEALTHY UPPER-LVL WAVE ACCOMPANIES IT...SO
MOST SXNS SHOULD SEE SHRA/SHSN WITH THE FROPA.
INITIALLY...THE DEEP-LYRD FLOW IS PROGGED TO BE SWLY FRI AFTN
POST-FROPA...SO AS THE LAKES BEGIN TO FIRST RESPOND TO THE INCOMING
COLD AIR...THE BRUNT OF THE LES SHOULD STAY N AND W OF THE
CWA...WITH JUST SCTD -SHSN/FLRYS ANTICIPATED IN CNY/NRN TIER PA.
WINDS SHOULD BE STG AND GUSTY FRI AFTN...WITH DECENT ISALLOBARIC
FORCING AND GOOD MOMENTUM TRANSFER CONDITIONS AT PLAY. ADVSY LVL
WIND GUSTS ARE NOT OUT OF THE QUESTION (35-45 KT)...SPCLY OUR
NRN/WRN ZNS...AND LATER SHIFTS WILL BE TAKING A CLOSER LOOK AT THIS.
FRI NGT AND SAT...AS A SECONDARY SFC TROUGH PUSHES THROUGH...AND
ADDITIONAL UPPER-LVL WAVES TRAVERSE THE RGN...THE BLYR FLOW SHOULD
VEER MORE INTO A 280-300 VECTOR WITH TIME. THIS SHOULD STEER MORE
PERSISTENT LES INTO OUR FA.
THE BEST OPPORTUNITY FOR MORE SIG LES MAY BE RESTRICTED TO A
RELATIVELY NARROW WINDOW FRI NGT...WHEN THE BEST COMBO OF CYCLONIC
FLOW AND DEEPER MOIST/PSBL MULTI-LK INFLUENCE EXISTS. HOWEVER...THE
DETRACTING ELEMENTS OF TRANSITIONAL FLOW AND TERRESTRIAL INSTAB FRI
EVE ALSO SEEM TO BE THERE. TIME WILL TELL ON HOW THIS ALL SHAKES
OUT...BUT WE DO HAVE LIKELY POPS FOR SHSN FROM LATER FRI AFTN INTO
EARLY SAT ACROSS MANY OF OUR NRN ZNS.
AS WE HEAD THRU THE DAY SAT...THE INVERSION SHOULD LWR
SUBSTANTIALLY...WITH THE MOIST SUPPLY ALSO WANING. THUS...MORE
PERSISTENT SHSN SHOULD DIMINISH TO SCTD -SHSN/FLRYS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
3 PM UPDATE...
SATURDAY NIGHT/SUNDAY...850 TEMPS OF -16C TO -18C AND A NORTHWEST
FLOW WILL BE FAVORABLE FACTORS FOR LAKE EFFECT SNOW DURING THIS
TIME BUT A LOW INVERSION (4KFT SATURDAY NIGHT THEN LOWERING
SUNDAY) ALONG WITH DRY AIR WILL INHIBIT MUCH FROM HAPPENING. STILL
WITH COLD AIR IN PLACE EXPECT A FEW FLURRIES OR A BRIEF SNOW
SHOWER ESPECIALLY FROM SYRACUSE DOWN THROUGH THE CORTLAND AREA ON
A 320 FLOW.
SUNDAY NIGHT/MONDAY....HIGH PRESSURE BUILDING SOUTH ACROSS THE
AREA WILL KEEP THIS PERIOD DRY AND QUIET. WITH A BETTER SHOT AT A
CLEAR SKY SUNDAY NIGHT...MORNING LOWS MONDAY WILL BE IN THE SINGLE
DIGITS FOR MOST OF THE AREA WITH READINGS BELOW ZERO OVER THE FAR
EAST AND NORTH.
TUESDAY/WEDNESDAY....AN AREA OF LOW PRESSURE MOVING THROUGH THE
NORTHERN GREAT LAKES STILL LOOKS TO BRING US OUR NEXT SHOT AT
SIGNIFICANT PRECIPITATION. BOTH THE EURO AND GFS ARE PRETTY SIMILAR
WITH THE TRACK BEING WELL TO OUR NORTH AND WEST...BUT THEY DIFFER
ON HOW MUCH WARM AIR IS DRAWN UP AHEAD OF THE SYSTEM. ONE THING IS
FOR SURE...THE COLD AIR WHICH WILL BE IN PLACE THIS UPCOMING
WEEKEND WILL BE RETREATING OUT TO SEA BUT MANY QUESTIONS REMAIN ON
HOW MUCH OF IT REMAINS BEHIND. WITH NO CLEAR-CUT SOLUTION
CONTINUED TO PLAY IT A RAIN/SNOW MIX TUESDAY WITH A TRANSITION TO
SNOW TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
UPDATED AS OF 645 PM WED... VFR AT THE OUTSET FOR ALL TERMINAL
SITES EARLY THIS EVE. HOWEVER...AS STEADIER PCPN OVERSPREADS THE
RGN THROUGH 04-06Z...CONDS WILL DETERIORATE...AND MVFR SHOULD DEVELOP.
AS FAR AS PTYP IS CONCERNED...TEMPS SHOULD BE COLD ENOUGH FOR A
WINTRY MIX MUCH OF THE OVERNIGHT PD AT KRME...WITH -SNPL AT THE
BEGINNING...THEN MOSTLY -FZRA AFTER 06Z. BY 09Z OR SO...KRME
SHOULD BE OVER TO PLAIN RAIN. ELSEWHERE...MOSTLY RAIN ANTICIPATED
(KBGM MAY SEE A TOUCH OF -SNPL AT THE VERY START...BUT IT SHOULD
BE BRIEF).
DURING THE PRE-DAWN HRS AND THEN THROUGH THE AM ON THU...CONDS
SHOULD BE AT THEIR LOWEST...DUE MAINLY TO CIG RESTRICTIONS. FOR
MOST OF THE AREA...THIS SHOULD TRANSLATE TO IFR CIG BASES.
HOWEVER...KAVP MAY WELL STAY IN THE MVFR CAT...AS DOWNSLOPING SELY
FLOW COULD MITIGATE ANY PSBL IFR CONDS.
THU AFTN (MOSTLY AFTER 18Z)...A VERY GRADUAL IMPROVEMENT IS
FORESEEN...AS STEADIER PCPN WILL BE LONG GONE...AND LWR LVL WINDS
SLOWLY SWITCH FROM ESE TO SWLY. STILL THOUGH...MVFR SHOULD BE THE
PREVAILING CAT.
E TO SE WINDS OVERNIGHT AND THU AM (GUSTY AT KAVP...KITH...AND
KBGM)...WILL LIGHTEN UP AND TURN SW BY THU AFTN MOST SITES.
.OUTLOOK...
THU NGT...RESTRICTIONS LIKELY...DUE TO LWR CIGS/SCTD -SHRA.
FRI...GUSTY WINDS AND PSBL RESTRICTIONS IN SHSN...ESPECIALLY
KRME/KSYR.
FRI NGT/SAT...MVFR/IFR IN LAKE-EFFECT SHSN KSYR/KRME...WITH
RESTRICTIONS ALSO PSBL AT KBGM/KITH/KELM.
SUN/MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR PAZ040-048-
072.
NY...WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ036-045-
062.
WINTER WEATHER ADVISORY UNTIL NOON EST THURSDAY FOR NYZ009-037-
046-057.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MLJ
LONG TERM...HEDEN
AVIATION...MLJ/SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
806 PM EST WED JAN 11 2012
.SYNOPSIS...
A STORM SYSTEM WILL BRING PRECIPITATION TONIGHT INTO THURSDAY.
EAST OF INTERSTATE 81...ESPECIALLY AT HIGHER ELEVATIONS...THE
PRECIPITATION MAY BEGIN AS A WINTRY MIX OF FREEZING
RAIN...SLEET...AND SNOW. THE REMAINDER OF THE REGION WILL
GENERALLY HAVE JUST A COLD RAIN. HOWEVER...A COLD FRONT WILL SWEEP
THROUGH LATE THURSDAY NIGHT INTO FRIDAY MORNING...RESULTING IN
SNOW SHOWERS DURING THE DAY FRIDAY. COURTESY OF LAKE EFFECT...SNOW
SHOWERS CONTINUE INTO SATURDAY FOR MUCH OF THE REGION.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
730 PM UPDATE...OVERALL FORECAST EVOLUTION IS IN GOOD SHAPE.
PRECIPITATION IS ADVANCING ACROSS THE SOUTHERN THIRD OF THE CWA AS
WE SPEAK. PREFER THE NAM/RUC FORECAST SOUNDINGS WHICH SHOW THE
PRECIPITATION STARTING OFF MOSTLY AS ALL RAIN IN THE LOWER
ELEVATIONS...WITH A MIX OF ANYTHING FROM RAIN TO SLEET OR EVEN A
FEW SNOWFLAKES ABOVE 1200 FEET. TAMDAR SOUNDINGS OUT OF SYRACUSE
SHOW THIS NICELY WITH PLENTY OF DRY AIR IN THE MID LEVELS ALLOWING
FOR SOME QUICK WET BULBING...BEFORE OUR WARM NOSE PUNCHES IN
AROUND 850 MB. THIS PUNCH OF WARMER AIR WILL TRANSITION MOST OF
THE AREA TO PLAIN RAIN. THE EXCEPTION WILL BE FARTHER EAST AND
NORTH...WHERE WE HAD ADVISORIES IN PLACE...WHERE THE MIX OF
SLEET/SNOW...AND EVEN SOME FREEZING RAIN WILL LINGER MUCH LONGER.
MAIN ADJUSTMENT TO THIS PACKAGE IS TO LOWER SNOWFALL AMOUNTS.
WHILE SOME SNOW IS POSSIBLE NEAR THE ONSET AND SHORTLY
THEREAFTER...FEEL THE WARM NOSE DEPICTED ON THE RUC AND NAM WILL
BE ENOUGH TO HELP US MIX WITH SLEET QUICKLY...THUS CUTTING DOWN
SNOWFALL AMOUNTS. AT THIS POINT SEE NOTHING MORE THAN A COATING OF
SNOWFALL OVER THE FAR EAST...WITH OUR ADVISORIES JUSTIFIED BY A
COMINBATION OF SLEET AND ESPECIALLY FREEZING RAIN.
AFTER 07Z ENOUGH WARM AIR ALOFT WILL MOVE INTO THE AREA THAT IT
WILL BE JUST A RAIN OR FREEZING RAIN SITUATION...WITH ALL THE
EMPHASIS SHIFTING TO OUR SURFACE TEMPS. OUR NORMALLY COLDER SPOTS
FROM NORTHERN OTSEGO COUNTY INTO THE MOHAWK VALLEY REMAIN AT THE
HIGHEST RISK FOR A PROLONGED PERIOD OF LIGHT FREEZING RAIN. THIS
IS WELL SUPPORTED BY OBS IN THE CENTRAL MOHAWK VALLEY THAT ARE
ALREADY BELOW FREEZING...WITH DEW-POINTS IN THE LOWER TO MIDDLE
20S.
LOOK FOR OUR NEXT UPDATE AROUND 10 PM. IF WE CONTINUE TO SEE TEMPS
ABOVE FREEZING IN NORTHERN PA...WE MAY BE ABLE TO TRIM BACK OUR
ADVISORY FROM SOUTH TO NORTH.
415 PM
UPDATE...TREND FOR A WARMER INCIPIENT BOUNDARY LAYER CONTINUES IN
THE MODELS...AS SYSTEM MOVES IN TONIGHT. THUS I DO NOT SEE A NEED
FOR ANY FURTHER EXPANSION OF CURRENT WINTER WEATHER
ADVISORY...WHICH INCLUDES COUNTIES EAST OF INTERSTATE 81. FOR
COUNTIES ALONG AND WEST OF INTERSTATE 81...HIGH CONFIDENCE NOW
THAT PRECIPITATION TYPE WILL BE ALL RAIN...WITH PERHAPS ONLY A
LITTLE BRIEF SLEET BUT WITH TEMPERATURES STAYING ABOVE FREEZING.
AND OF THE WINTER WEATHER ADVISORY COUNTIES...TRANSITION TO PLAIN
RAIN WILL OCCUR EARLY FOR ALL BUT ONEIDA/DELAWARE/OTSEGO...SO I
MOVED UP THE END TIME FOR THOSE ZONES TO 6 AM. FOR THE EARLIER
ENDING ZONES...ICE AND SNOW ACCUMULATIONS LOOK TO BE FAIRLY LIGHT
AND MAINLY AT HIGHER ELEVATIONS. MANY VALLEY LOCATIONS MAY GET
THROUGH WITH ONLY PLAIN RAIN OR A LITTLE LIGHT SLEET.
COLD AIR WILL LINGER LONGER IN THE NORTHEASTERN ZONES COURTESY OF
COLD AIR DAMMING...SO WINTRY MIX WILL LAST INTO THE MORNING. WE
WILL HAVE TO WATCH CLOSELY FOR ICE ACCUMULATIONS IN EXCESS OF A
QUARTER INCH...IN PARTICULAR TOWARDS THE MOHAWK VALLEY/SOUTHERN
TUG HILL PLATEAU...SHOULD THE COLD AIR TAKE LONG TO SCOUR OUT.
SNOW ACCUMULATIONS MEANWHILE WILL BE OF HIGH WATER
CONTENT...GENERALLY 1 TO 3 INCHES AND MAINLY AT HIGHER ELEVATIONS.
WHATEVER THE TYPE...FOR THE AREA IN GENERAL RAW PRECIPITATION
AMOUNTS WILL RANGE FROM A HALF INCH OR SO IN THE WEST-
NORTHWEST...TO ALMOST AN INCH IN THE SOUTHEAST. AFTER A BRIEF DIP
IN TEMPERATURES EARLY THIS EVENING...LOOKING FOR STEADY TO
SLOWLY RISING TEMPERATURES OVERNIGHT. FINGER LAKES...SOUTHERN
TIER OF NY...AND MOST OF NORTHEAST PA WILL EVENTUALLY GET INTO
THE 40S THURSDAY.
DEEPER MOISTURE EXITS WITH THE OCCLUDED FRONT MIDDAY
THURSDAY...LEAVING LIGHT SHOWERS OR PERHAPS DRIZZLE IN THE
AFTERNOON TO EVENING. BOUNDARY LAYER WILL BE SLOW TO COOL THURSDAY
NIGHT...UNTIL ARRIVAL OF STRONG NEGATIVELY TILTED COLD FRONT
TOWARDS DAWN FRIDAY. SO CHANGEOVER OF ANY REMAINING LIGHT RAIN
SHOWERS TO SNOW...WILL BE GRADUAL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
UPDATED AS OF 4 PM WED... MODEL CONSENSUS IS FAIRLY GOOD ON SYSTEM
EVOLUTION THIS PD.
A STG COLD FRONT IS SLATED TO CROSS THE FA FROM SW TO NE FRI
AM...GENERALLY IN THE 12-15Z TIME FRAME. QG FORCING IS PRETTY POTENT
WITH THIS FRNT...AS A HEALTHY UPPER-LVL WAVE ACCOMPANIES IT...SO
MOST SXNS SHOULD SEE SHRA/SHSN WITH THE FROPA.
INITIALLY...THE DEEP-LYRD FLOW IS PROGGED TO BE SWLY FRI AFTN
POST-FROPA...SO AS THE LAKES BEGIN TO FIRST RESPOND TO THE INCOMING
COLD AIR...THE BRUNT OF THE LES SHOULD STAY N AND W OF THE
CWA...WITH JUST SCTD -SHSN/FLRYS ANTICIPATED IN CNY/NRN TIER PA.
WINDS SHOULD BE STG AND GUSTY FRI AFTN...WITH DECENT ISALLOBARIC
FORCING AND GOOD MOMENTUM TRANSFER CONDITIONS AT PLAY. ADVSY LVL
WIND GUSTS ARE NOT OUT OF THE QUESTION (35-45 KT)...SPCLY OUR
NRN/WRN ZNS...AND LATER SHIFTS WILL BE TAKING A CLOSER LOOK AT THIS.
FRI NGT AND SAT...AS A SECONDARY SFC TROUGH PUSHES THROUGH...AND
ADDITIONAL UPPER-LVL WAVES TRAVERSE THE RGN...THE BLYR FLOW SHOULD
VEER MORE INTO A 280-300 VECTOR WITH TIME. THIS SHOULD STEER MORE
PERSISTENT LES INTO OUR FA.
THE BEST OPPORTUNITY FOR MORE SIG LES MAY BE RESTRICTED TO A
RELATIVELY NARROW WINDOW FRI NGT...WHEN THE BEST COMBO OF CYCLONIC
FLOW AND DEEPER MOIST/PSBL MULTI-LK INFLUENCE EXISTS. HOWEVER...THE
DETRACTING ELEMENTS OF TRANSITIONAL FLOW AND TERRESTRIAL INSTAB FRI
EVE ALSO SEEM TO BE THERE. TIME WILL TELL ON HOW THIS ALL SHAKES
OUT...BUT WE DO HAVE LIKELY POPS FOR SHSN FROM LATER FRI AFTN INTO
EARLY SAT ACROSS MANY OF OUR NRN ZNS.
AS WE HEAD THRU THE DAY SAT...THE INVERSION SHOULD LWR
SUBSTANTIALLY...WITH THE MOIST SUPPLY ALSO WANING. THUS...MORE
PERSISTENT SHSN SHOULD DIMINISH TO SCTD -SHSN/FLRYS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
3 PM UPDATE...
SATURDAY NIGHT/SUNDAY...850 TEMPS OF -16C TO -18C AND A NORTHWEST
FLOW WILL BE FAVORABLE FACTORS FOR LAKE EFFECT SNOW DURING THIS
TIME BUT A LOW INVERSION (4KFT SATURDAY NIGHT THEN LOWERING
SUNDAY) ALONG WITH DRY AIR WILL INHIBIT MUCH FROM HAPPENING. STILL
WITH COLD AIR IN PLACE EXPECT A FEW FLURRIES OR A BRIEF SNOW
SHOWER ESPECIALLY FROM SYRACUSE DOWN THROUGH THE CORTLAND AREA ON
A 320 FLOW.
SUNDAY NIGHT/MONDAY....HIGH PRESSURE BUILDING SOUTH ACROSS THE
AREA WILL KEEP THIS PERIOD DRY AND QUIET. WITH A BETTER SHOT AT A
CLEAR SKY SUNDAY NIGHT...MORNING LOWS MONDAY WILL BE IN THE SINGLE
DIGITS FOR MOST OF THE AREA WITH READINGS BELOW ZERO OVER THE FAR
EAST AND NORTH.
TUESDAY/WEDNESDAY....AN AREA OF LOW PRESSURE MOVING THROUGH THE
NORTHERN GREAT LAKES STILL LOOKS TO BRING US OUR NEXT SHOT AT
SIGNIFICANT PRECIPITATION. BOTH THE EURO AND GFS ARE PRETTY SIMILAR
WITH THE TRACK BEING WELL TO OUR NORTH AND WEST...BUT THEY DIFFER
ON HOW MUCH WARM AIR IS DRAWN UP AHEAD OF THE SYSTEM. ONE THING IS
FOR SURE...THE COLD AIR WHICH WILL BE IN PLACE THIS UPCOMING
WEEKEND WILL BE RETREATING OUT TO SEA BUT MANY QUESTIONS REMAIN ON
HOW MUCH OF IT REMAINS BEHIND. WITH NO CLEAR-CUT SOLUTION
CONTINUED TO PLAY IT A RAIN/SNOW MIX TUESDAY WITH A TRANSITION TO
SNOW TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
UPDATED AS OF 645 PM WED... VFR AT THE OUTSET FOR ALL TERMINAL
SITES EARLY THIS EVE. HOWEVER...AS STEADIER PCPN OVERSPREADS THE
RGN THROUGH 04-06Z...CONDS WILL DETERIORATE...AND MVFR SHOULD DEVELOP.
AS FAR AS PTYP IS CONCERNED...TEMPS SHOULD BE COLD ENOUGH FOR A
WINTRY MIX MUCH OF THE OVERNIGHT PD AT KRME...WITH -SNPL AT THE
BEGINNING...THEN MOSTLY -FZRA AFTER 06Z. BY 09Z OR SO...KRME
SHOULD BE OVER TO PLAIN RAIN. ELSEWHERE...MOSTLY RAIN ANTICIPATED
(KBGM MAY SEE A TOUCH OF -SNPL AT THE VERY START...BUT IT SHOULD
BE BRIEF).
DURING THE PRE-DAWN HRS AND THEN THROUGH THE AM ON THU...CONDS
SHOULD BE AT THEIR LOWEST...DUE MAINLY TO CIG RESTRICTIONS. FOR
MOST OF THE AREA...THIS SHOULD TRANSLATE TO IFR CIG BASES.
HOWEVER...KAVP MAY WELL STAY IN THE MVFR CAT...AS DOWNSLOPING SELY
FLOW COULD MITIGATE ANY PSBL IFR CONDS.
THU AFTN (MOSTLY AFTER 18Z)...A VERY GRADUAL IMPROVEMENT IS
FORESEEN...AS STEADIER PCPN WILL BE LONG GONE...AND LWR LVL WINDS
SLOWLY SWITCH FROM ESE TO SWLY. STILL THOUGH...MVFR SHOULD BE THE
PREVAILING CAT.
E TO SE WINDS OVERNIGHT AND THU AM (GUSTY AT KAVP...KITH...AND
KBGM)...WILL LIGHTEN UP AND TURN SW BY THU AFTN MOST SITES.
.OUTLOOK...
THU NGT...RESTRICTIONS LIKELY...DUE TO LWR CIGS/SCTD -SHRA.
FRI...GUSTY WINDS AND PSBL RESTRICTIONS IN SHSN...ESPECIALLY
KRME/KSYR.
FRI NGT/SAT...MVFR/IFR IN LAKE-EFFECT SHSN KSYR/KRME...WITH
RESTRICTIONS ALSO PSBL AT KBGM/KITH/KELM.
SUN/MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR PAZ040-048-
072.
NY...WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ036-045-
062.
WINTER WEATHER ADVISORY UNTIL NOON EST THURSDAY FOR NYZ009-037-
046-057.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MLJ
LONG TERM...HEDEN
AVIATION...MLJ/SLI
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
551 PM CST WED JAN 11 2012
.UPDATE...
WILL ALLOW THE WIND ADVISORY TO EXPIRE AT 6PM ACROSS THE REGION
WITH WIND SPEEDS DROPPING BELOW CRITERIA.
&&
.AVIATION...
WINDY CONDITIONS EARLY THIS EVENING WILL QUICKLY DIMINISH WITH THE
NEXT FEW HOURS. BORDERLINE MVFR CONDITIONS WILL PERSIST AT KCDS AS
WELL WITH THESE CONDITIONS ENTERING THE KLBB TAF SITE LATER THIS
EVENING. NORTHERLY WINDS WILL REMAIN BREEZY THROUGH THE NIGHT WITH
AN EVENTUAL DECREASE IN LOW AND HIGH CLOUDS.
&&
.PREV DISCUSSION... /ISSUED 352 PM CST WED JAN 11 2012/
SHORT TERM...
THE SURFACE PRESSURE GRADIENT SUPPORTING TODAYS STIFF NORTHERLY
WINDS IS EXPECTED TO EASE STEADILY THIS EVENING...WITH DROP IN MOST
SURFACE WIND SPEEDS NEAR OR PRIOR TO 00Z THIS EVENING. OUR PLAN IS
TO ALLOW THE WIND ADVISORY TO RUN ITS COURSE UNTIL 00Z WITH NO
EXTENSION. WINDS PROBABLY WILL BE SLOWEST TO DROP THIS EVENING OVER
THE ROLLING PLAINS AND MAY RETAIN GREATER THAN 10 MPH WINDS UNTIL
CLOSE TO DAYBREAK ON THURSDAY. THIS SHOULD KEEP ESPECIALLY THE
SOUTHERN ROLLING PLAINS BETTER MIXED WHILE LOW TEMPERATURES
OTHERWISE TONIGHT SHOULD DROP INTO TEENS ON MOST OF THE CAPROCK AND
LOW TO MID 20S OVER ROLLING PLAINS. THE UPPER FLOW SHOULD REMAIN
SLIGHTLY ANTICYCLONICALLY CURVED IN NORTHWEST FLOW ALOFT WITH A
BRANCH OF THE POLAR JET STILL OVER THE AREA UNTIL MIDDAY THURSDAY.
THIS MAY LEAD TO AREAS OF MID CLOUDS AGAIN LATER TONIGHT AND/OR
THROUGH THURSDAY...THOUGH SOMEWHAT DIFFICULT TO ANTICIPATE. LOW
CLOUDS TONIGHT ALSO SOMEWHAT UNCERTAIN GIVEN PREDOMINANT NORTHERLY
LOW LEVEL FLOW AND VERY DRY AIR...THOUGH RUC INDICATES ABOUT 20
DEGREES MORE NORTHEAST COMPONENT AND MAINTAINS MORE H850 LAYER
MOISTURE ACROSS NORTHERN AND EASTERN ZONES. SO...APPEARS PERHAPS
BEST AREAS FOR MVFR LAYER LOW CLOUDS WOULD BE ACROSS NORTHEAST ZONES
BUT CANT RULE OUT FOR CENTRAL. EITHER WAY...A CHILLY NIGHT WILL
OCCUR WITH A FLATTER SURFACE PRESSURE GRADIENT DOMINATING THROUGH
MUCH OF THURSDAY. TRENDED HIGHS THURSDAY VERY SLIGHTLY UPWARDS ALONG
LINES OF GUIDANCE TRENDS AS WELL. RMCQUEEN
LONG TERM...
EXPECT DRY CONDITIONS AND MODERATING TEMPERATURES LATE WEEK ON
THROUGH THE WEEKEND. INITIALLY...A SHORTWAVE TROUGH EMBEDDED WITHIN
NORTHWESTERLY FLOW ALOFT WILL TRAVERSE THE AREA FRIDAY. THIS
DISTURBANCE WILL GENERATE AREAS OF MID/HIGH CLOUD BUT LITTLE ELSE.
THE NORTHWESTERLY FLOW WILL BACK WITH TIME WITH A PROGRESSIVE UPPER
RIDGE TRANSLATING OVER SATURDAY NIGHT AND SUNDAY. THIS
PATTERN...COMBINED WITH INCREASING SOUTHERLY/SOUTHWESTERLY LOW-
LEVEL FLOW...WILL PUSH HIGHS BACK ABOVE AVERAGE OVER THE WEEKEND
/LIKELY ECLIPSING THE 60 DEGREE MARK BY SUNDAY/. ONE MINOR CAVEAT
REVOLVE AROUND A CLIPPER SYSTEM DIVING INTO THE UPPER MIDWEST THAT
MAY ATTEMPT TO BACKDOOR A WEAK COLD FRONT INTO THE NORTHEAST ZONES
ON SATURDAY. EVEN IF THIS FRONT DOES MAKE IT INTO THE AREA...ONLY
MINOR IMPACTS ARE EXPECTED. THUS...HAVE TRENDED FORECAST
TEMPERATURES UP A NOTCH OVER THE WEEKEND.
ATTENTION WILL THEN TURN TO ANOTHER SHORTWAVE TROUGH /THE REMNANTS
OF THE CUTOFF LOW CURRENTLY SPINNING WELL OFF THE CALIFORNIA COAST/
THAT WILL RACE BY THE REGION IN NEAR ZONAL FLOW ALOFT ON MONDAY.
UNFORTUNATELY THE PROGRESSIVE AND OPENING/WEAKENING NATURE OF THE
SYSTEM...ALONG WITH THE DEARTH OF LOW-LEVEL MOISTURE TO WORK
WITH...WILL LIKELY KEEP THIS SYSTEM A DRY ONE LOCALLY. HOWEVER...IF
YOU LIKE WIND YOU MAY BE IN STORE FOR ANOTHER TREAT AS THE LATEST
GUIDANCE AND RAW NWP MODEL OUTPUT SUGGEST WESTERLY WINDS MAY
APPROACH OR EXCEED ADVISORY LEVELS DURING THE DAY MONDAY.
HENCE...HAVE TRENDED WINDS SPEEDS UPWARD IN THE GRIDS...THOUGH A
TOUCH BELOW ADVISORY LEVELS AT THIS POINT. THESE WINDS COULD ALSO
LOFT A BIT OF BLOWING DUST /LIKE TODAY/ AND ALSO ELEVATE THE FIRE
DANGER. HOWEVER...CURRENT PROJECTIONS DO KEEP HUMIDITIES ABOVE MORE
CRITICAL THRESHOLDS...THOUGH THIS COULD BE A BIT OPTIMISTIC AS IS
OFTEN THE CASE IN THE STRONG WESTERLY FLOW REGIME.
BEYOND MONDAY...A COLD FRONT IS PROGGED TO MOVE THROUGH EARLY
TUESDAY...DROPPING TEMPERATURES TOWARD MORE SEASONAL LEVELS. THE
LATEST ROUND OF MODEL SOLUTIONS HAVE TRENDED A LITTLE STRONGER WITH
THE FRONT...PUSHING IT THROUGH THE ENTIRE FA...AND HAVE FOLLOWED
SUITE IN THE GRIDS. THIS COOL-DOWN SHOULD BE RELATIVELY SHORT-LIVED
THOUGH AS THE SFC RIDGE IS QUICKLY SHUNTED EASTWARD UNDER MODERATE
TO STRONG MID-LEVEL ZONAL FLOW IN PLACE ACROSS MUCH OF THE CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 16 41 18 47 23 / 10 0 0 0 0
TULIA 17 42 17 49 22 / 10 0 0 0 0
PLAINVIEW 18 42 19 50 23 / 10 0 0 0 0
LEVELLAND 19 43 21 51 25 / 10 0 0 0 0
LUBBOCK 19 43 21 51 23 / 10 0 0 0 0
DENVER CITY 21 42 23 49 26 / 0 0 0 0 0
BROWNFIELD 22 43 23 50 25 / 0 0 0 0 0
CHILDRESS 23 45 20 53 24 / 10 0 0 0 0
SPUR 24 46 23 53 26 / 10 0 0 0 0
ASPERMONT 25 46 25 54 25 / 10 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>044.
&&
$$
01
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
948 PM CST WED JAN 11 2012
.UPDATE...VIGOROUS SHORT WAVE OVER CENTRAL NE/NRN KS CONTINUING TO
DIG SWD AS TROUGH CONTINUES TO DEEPEN. NO CHANGES WITH WINTER WX
ADVY HEADLINES AT THIS TIME. NEXT SHIFT MAY WANT TO CONSIDER
PUSHING BACK START TIME OF ADVY IN PORTIONS OF ERN CWA UNTIL LATE
MRNG OR EARLY AFTN AS STEADY SNOW AND PERIODS OF MODERATE SNOW NOT
EXPECTED TO BEGIN IN THE LAKESHORE COUNTIES UNTIL LATE MORNING OR
EARLY AFTN. STRONGEST LIFT WITH STRONG SHORT WAVE AND LEFT
ENTRANCE REGION OF UPPER JET REMAINS SOUTH OF WI ON THU AND THU
NGT. STEADY LIFT ASSOCD WITH ISENTROPIC UPGLIDE WITH ONE OR TWO
BURSTS OF MODERATE SNOW WITH STRONGER OMEGA IN 100MB DENDRITIC
GROWTH ZONE TO MOVE FROM WEST TO EAST ACROSS SRN WI DURING THE
AFTN/EVE. TOTAL QPF OF .3 TO .5 INCHES SHOULD RESULT IN WIDESPREAD
5 TO 8 INCH AMOUNTS. STILL NEED TO CONSIDER THE AMOUNT OF BLOWING
SNOW ASSOCIATED WITH THOSE GUSTS TO 30KTS.
&&
.AVIATION/06Z TAFS/...LOW CLOUDS ASSOCD WITH SURGE OF COLD AIR
ADVECTION BEHIND FRONT HAVE SPREAD INTO KMSN. LOW CLOUDS SHOULD
CONTINUE SPREADING EWD ACROSS REST OF SRN WI OVERNIGHT. DECREASING
VSBYS ASSOCD WITH -SN SHOULD BEGIN TO AFFECT KMSN
10-13Z...EVENTUALLY SPREADING INTO SOUTHEAST WI THROUGH THE LATE
MRNG AND EARLY AFTN.
&&
.MARINE...DEVELOPING TIGHT PRESSURE AND LOW LEVEL INSTABILITY WILL
RESULT IN WIND GUSTS APPROACHING GALE THRESHOLD THURSDAY NIGHT
INTO EARLY FRIDAY. AT THIS TIME...APPEARS GUSTS EXCEEDING 33KTS
WOULD BE INFREQUENT...SO WL HOLD OFF ON GALE WATCH/WARNING AT THIS
TIME. BEEFED UP WIND SPEEDS TO 20 TO 30 KNOTS BY THURSDAY
AFTN...CONTINUING INTO FRI MRNG. COLD TEMPERATURES AND LINGERING
BRISK WINDS WL LIKELY CAUSE AREAS OF FREEZING SPRAY ON FRI AS WELL.
&&
.PREV DISCUSSION... /ISSUED 225 PM CST WED JAN 11 2012/
SHORT TERM...
TONIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
DECIDED ON A WINTER WEATHER ADVISORY HEADLINE INSTEAD OF A WINTER
STORM WARNING DUE TO THE LONG DURATION OF THIS EVENT.
SFC WIND SHIFT AND COLD FRONT JUST GETTING INTO WEST CENTRAL WI THIS
AFTERNOON BRINGING INTIALLY JUST LOW CLOUDS. TIMING OF THIS FRONT
GETTING INTO SOUTH CENTRAL WI KEEPS TRENDING SLOWER.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW 500MB LOW OVER
SOUTHEASTERN U.S. AND AN ELONGATED TROUGH DIPPING DOWN INTO THE
DAKOTAS. THE LONGWAVE TROUGH WILL BECOME A CLOSED 500MB LOW OVER
MO/IL BETWEEN 18Z THU AND 00Z FRI...WHICH WILL FURTHER DEEPEN AND
BECOME NEGATIVELY TILTED AS IT MOVES EAST INTO OHIO 06Z-12Z FRI.
EVEN THOUGH THE TWO UPPER LEVEL SYSTEMS WILL NOT MERGE...THE
MOISTURE WRAPPED INTO THE SOUTHEAST LOW WILL BE PULLED NORTHWESTWARD
INTO THE UPPER GREAT LAKES REGION. 285K TO 300K ISENTROPIC LIFT WILL
BRING AN EXTRA SURGE OF MOISTURE LIFT INTO LAKE MICHIGAN AND EASTERN
WI BETWEEN 18Z THU-06Z FRI. THIS WILL COMBINE WITH OMEGA VALUES OF
-5 TO -6 IN THE DENDRITIC GROWTH ZONE TO CREATE MODERATE SNOW AND
HALF INCH PER HOUR SNOWFALL RATES.
COLD TEMPS FLOWING INTO THE REGION WITH THE STRONG COLD FRONT WILL
BLOW THE SNOW AROUND THU AFTERNOON AND HELP TO KNOCK DOWN SNOW
RATIOS LATER THU AFTERNOON AND THU NIGHT. NAM SNOW RATIOS IN THE 14
TO 16:1 RANGE LOOK GOOD THROUGH 21Z THU...THEN CUT THE NAM RATIOS
DOWN A BIT TO STAY WITHIN THE 15 TO 17:1 RANGE THROUGH 06Z FRI.
IT/S IMPORTANT TO STRESS THAT THE CALCULATED SNOWFALL TOTALS OF 6 TO
8 INCHES WILL FALL OVER A VERY LONG TIME PERIOD FROM LATE TONIGHT
THROUGH EARLY FRIDAY AFTERNOON. THIS STORM TOTAL WAS DETERMINED BY
ADDING UP 6-HOURLY SNOWFALL GRIDS...AND DOES NOT REPRESENT HOW MANY
INCHES WILL BE ON A SNOW BOARD BY THE END OF THE EVENT. USE CAUTION
WHEN SITING THE STORM TOTAL SNOWFALL AMOUNTS!
THE BRUNT OF THE SNOW WILL COME BETWEEN MID THU MORNING AND MID THU
EVENING. THE MORNING COMMUTE IN MADISON WILL BE MESSY IF THIS STORM
KEEPS ITS CURRENT PACE. THE AFTERNOON COMMUTE WILL BE MESSY IN BOTH
MADISON AND MILWAUKEE WITH THE HIGHER SNOW RATES AND WIND BLOWING
THE SNOW AROUND. GIVEN THE LONG DURATION EVENT...SNOW PLOWS SHOULD
BE ABLE TO KEEP UP WITH THE SNOWFALL...WITH HIGHEST SNOW RATES OF A
HALF INCH PER HOUR FOR 4 TO 6 HOURS.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
MID/UPPER TROUGH EXITS THE EASTERN GREAT LAKES REGION BY FRIDAY.
STRONG SURFACE LOW OVER LOWER MICHIGAN THURSDAY EVENING REACHES
THE EASTERN GREAT LAKES EARLY FRIDAY MORNING. ACCUMULATING SNOW
SHOULD CONTINUE THURSDAY EVENING...DIMINISHING BY FRIDAY MORNING.
12Z NAM/ECMWF SIMILAR IN PRECIPITATION AMOUNTS WITH THE GFS
SLIGHTLY LOWER.
LONG DURATION SNOW EVENT BUT APPEARS NO 12 HOUR PERIOD WILL REACH
6 INCHES AND 24 HOUR PERIOD WILL NOT REACH 8 INCHES SO WILL GO
WITH ADVISORY HEADLINES. WINDS/AND SOME BLOWING DRIFTING
SNOW...ESPECIALLY THURSDAY EVENING...BUT THIS NOT SEEM TO BE TOO
SEVERE TO WARRANT AN UPGRADE TO WARNING STATUS.
LONG TERM...
FRIDAY NIGHT AND SATURDAY......FORECAST CONFIDENCE...MEDIUM
SHORTWAVE IN THE NORTHWEST MID/UPPER LEVEL FLOW WILL MOVE ACROSS
THE NORTHERN PLAINS FRIDAY NIGHT AND MOVE ACROSS NORTHERN ILLINOIS
ON SATURDAY. ASSOCIATED WEAK SURFACE LOW IS EXPECTED TO TRACK
ACROSS NORTHERN ILLINOIS OR FAR SOUTHERN WISCONSIN. AN INCH OR
LESS OF SNOW POSSIBLE.
SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...MEDIUM
NORTHWEST MID/UPPER LEVEL FLOW SUNDAY UNTIL A RIDGE BUILDS INTO
WISCONSIN SUNDAY NIGHT AS A SHORTWAVE DIGS OVER THE WESTERN U.S.
AS A RESULT A SURFACE HIGH SHOULD EXTEND ACROSS THE GREAT LAKES.
SOUTH WINDS WILL INCREASE SUNDAY NIGHT AHEAD OF THE SURFACE TROUGH.
BY MONDAY MID/UPPER LEVEL FLOW BECOMES SOUTHWEST AS THE SHORTWAVE
MOVES EAST INTO THE ROCKIES/HIGH PLAINS REGION. BOTH THE 12Z GFS
AND 12Z ECMWF BRINGS A SURFACE TROUGH TO THE MISSISSIPPI VALLEY
WITH LIGHT PRECIPITATION SPREADING NORTH INTO SOUTHERN WISCONSIN.
BY THIS TIME THICKNESS VALUES RISE ABOVE 540 DM.
THE SHORTWAVE TROUGH SHOULD REACH THE UPPER MISSISSIPPI VALLEY
MONDAY NIGHT AND REACH THE GREAT LAKES ON TUESDAY. PRECIPITATION
SHOULD MIX WITH/CHANGE TO SNOW BEHIND THE SURFACE TROUGH/COLD FRONT.
PRECIPITATION WILL DIMINISH/END MONDAY NIGHT.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
SURFACE HIGH BUILDS INTO WISCONSIN TUESDAY NIGHT BEFORE THE HIGH
MOVES ACROSS KENTUCKY.
AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH ABOUT 01Z AT KMSN AND 05Z AT KMKE
AND OTHER SE WI TAF SITES. WEDGE OF CLEAR SKIES BETWEEN SYSTEM TO
OUR SOUTH AND APPROACHING ONE TO THE NORTHWEST SHOULD LAST INTO THE
EARLY EVENING WITH SOME HIGH CLOUDS INITIALLY SPREADING IN. LOW
CLOUDS WITH MVFR CONDITIONS WILL SINK QUICKLY TO IFR IN THE WAKE OF
THE PASSING COLD FRONT BETWEEN 01-05Z THU. ANY SNOW AT KMSN SHOULD
HOLD OFF UNTIL AFTER 06Z THU AND AFTER 12Z THU AT KMKE.
INITIAL SNOW IS EXPECTED TO BE LIGHT...THEN THE BEST STORM DYNAMICS
MOVE ACROSS WI FROM WEST TO EAST 12-18Z THU AND REMAIN NEARLY
STATIONARY OVER SOUTH CENTRAL AND SOUTHEAST WI THROUGH 00Z TO 06Z
FRI AS SFC LOW PRESSURE REGROUPS OVER SOUTHEAST LOWER
MICHIGAN...OCCLUDES AND WAITS FOR THE 500MB UPPER LOW TO SHIFT
EASTWARD ACROSS ILLINOIS AND INDIANA.
TOTAL SNOW AMOUNTS UP TO 8 INCHES WILL FALL OVER A VERY LONG TIME
PERIOD...RUNNING FROM LATE TONIGHT THROUGH FRIDAY MORNING. THE
HEAVIEST PERIOD WOULD BE BETWEEN 18Z THU THROUGH 06Z FRIDAY WHERE UP
TO 4 INCHES COULD FALL.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY
FOR WIZ047-057-063-068.
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO 9 AM CST FRIDAY
FOR WIZ051-052-058>060-064>066-069>072.
WINTER WEATHER ADVISORY FROM 3 AM THURSDAY TO 6 AM CST FRIDAY
FOR WIZ046-056-062-067.
LM...SMALL CRAFT ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT CST FRIDAY
NIGHT FOR LMZ643>646.
&&
$$
UPDATE...MBK
AREA FORECAST DISCUSSION
NWS DENVER CO
251 AM MST THU JAN 12 2012
.SHORT TERM...NW FLOW ALOFT WILL BE OVER THE AREA TODAY. GUSTY
WINDS WILL BE POSSIBLE IN THE MTNS AND ALONG THE FOOTHILLS THRU THE
MORNING HOURS WITH A FEW AREAS OF BLOWING SNOW. OVER NERN CO GUSTY
NWLY WINDS WILL ALSO OCCUR WHICH WILL LINGER THROUGH THE AFTN HOURS
BUT SPEEDS SHOULD STAY BLO HIGHLIGHT CRITERIA. AS FOR HIGHS WILL
KEEP READINGS MAINLY IN THE 35 TO 40 DEGREE RANGE OVER NERN CO.
FOR TONIGHT A WEAK UPPER LEVEL TROUGH IN NW FLOW WILL MOVE ACROSS
THE AREA HOWEVER CROSS-SECTIONS SHOW MOISTURE CONFINED TO THE MID
AND UPPER LEVELS. THUS WILL SEE AN INCREASE IN CLOUDS WITH ONLY A
FEW FLURRIES OVER THE HIGHER MTN PEAKS. LATE TONIGHT AS SUBSIDENCE
DEVELOPS BEHIND PASSAGE OF WEAK UPPER LEVEL TROUGH WINDS MAY
INCREASE IN AND NR THE FOOTHILLS HOWEVER SPEEDS SHOULD REMAIN BLO
WARNING CRITERIA.
.LONG TERM...MODELS HAVE STRONG NORTHERLY FLOW ALOFT FOR THE
FORECAST AREA ON FRIDAY...WITH AN UPPER RIDGE TO OUR WEST.
DECREASING NORTHWESTERLY FLOW ALOFT IS PROGGED FOR FRIDAY NIGHT
THROUGH SATURDAY. BY SATURDAY NIGHT...WEAK ZONAL FLOW ALOFT IS
PROGGED. THE QG VERTICAL VELOCITY FIELDS HAVE WEAK DOWNWARD MOTION
PROGGED FOR THE CWA THROUGH SATURDAY NIGHT. THE BOUNDARY LAYER FLOW
LOOKS TO BE A MIX OF THE NORMAL DIURNAL PATTERN COUPLED WITH
DOWNSLOPING WITH TROUGHING EAST OF THE MOUNTAINS THROUGH THE
PERIOD. FOR MOISTURE...THERE IS A BIT IN THE MID AND UPPER LEVELS
THROUGH THE PERIOD. THE IS NO MEASURABLE PRECIPITATION ON THE QPF
FIELDS THROUGH THE PERIOD. NO POPS. CROSS SECTIONS SHOW A BIT OF
MOUNTAINS WAVE SET UP FRIDAY AFTERNOON AND NIGHT. HOWEVER...IT IS
NOT SIGNIFICANT. FOR TEMPERATURES...FRIDAY`S HIGHS ARE 2-5 C WARMER
THAN TODAY`S. SATURDAY`S WARM-UP ANOTHER 2-4 C. WILL UNDERCUT MOS
GUIDANCE NUMBERS...ESPECIALLY IN THE AREAS WHERE THERE IS SNOW ON
THE GROUND. FOR THE LATER DAYS...SUNDAY THROUGH WEDNESDAY...ZONAL
FLOW GIVES WAY TO SOUTHWESTERLY FLOW ALOFT ON SUNDAY AND SUNDAY
NIGHT. THE ECMWF AND GFS BOTH SHOW A BROAD UPPER TROUGH TO MOVE
INTO COLORADO LATER MONDAY AND MONDAY NIGHT. BOTH HAVE A COLD FRONT
AND UPSLOPE FOR THE PLAINS AND FOOTHILLS MONDAY AFTERNOON AND
EVENING. IT IS A QUICK SHOT. FOR TUESDAY AND WEDNESDAY...
NORTHWESTERLY FLOW ALOFT IS PROGGED...AND THERE IS MOISTURE WITH
IT. PERHAPS OUR MOUNTAINS WILL SEE SOME SNOW. WILL LEAVE THE
EXTENDED GFE GRIDS PRETTY MUCH ALONE.
&&
.AVIATION...VFR THRU TONIGHT. WILL KEEP WINDS SSW THRU THE MORNING
HOURS AROUND 10 KTS. BY AFTN HRRR KEEPS WINDS MAINLY WSW WHILE THE
RUC HAS THEM SHIFTING TO MORE OF A WNW DIRECTION WITH SPEEDS AROUND
10 KTS. FOR NOW WILL TREND TOWARDS A WNW DIRECTON. BY EARLY
EVENING WINDS WILL GRADUALLY BECOME MORE WSW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
RPK/RJK
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1254 AM EST THU JAN 12 2012
.PREV DISCUSSION... /ISSUED 906 PM EST WED JAN 11 2012/
UPDATE...
FORECAST IS ON TRACK TONIGHT. WILL CONTINUE TO SEE EXTENSIVE CLOUD
COVERAGE OVERNIGHT BUT FOR THE MOST PART THE PRECIP HAS LIFTED OUT
OF THE AREA. RUC PROGS A WEAK VORT MAX QUICKLY MOVING ACROSS THE
STATE OVER THE NEXT FEW HOURS...BUT SEEING AS THIS ISNT PRODUCING
SHOWERS IN AL...DO NOT EXPECT TO SEE ANY SHOWERS ASSOCIATED WITH
IT HERE. CUT BACK ON POPS OVERNIGHT AND ONLY LEFT THEM IN ACROSS
NORTHEAST GEORGIA. DID ADD PATCHY DRIZZLE THOUGH TONIGHT FOR
EXTREME NORTH GEORGIA.
11
PREV DISCUSSION...
SHORT TERM /TONIGHT THROUGH FRIDAY/...
/ISSUED 254 PM EST WED JAN 11 2012/
SHOWERS AND ISOLATED THUNDERSTORMS REMAINED ACROSS NORTH GEORGIA
THIS AFTERNOON AS A RESULT OF LOW PRESSURE MOVING THROUGH THE
AREA. ASSOCIATED COLD FRONT EXPECTED TO MOVE INTO THE CAROLINAS
THIS EVENING WILL HAVE LITTLE IMPACT TO THE CWA...AHEAD OF A
SECOND COLD FRONT THAT WILL QUICKLY PUSH THROUGH ON THURSDAY.
INITIALLY...WRAP AROUND MOISTURE WILL KEEP NORTH GEORGIA IN A
FAVORABLE PRECIP AREA...BUT THIS MOISTURE...COMBINED WITH THE
SOUTHERLY FLOW AHEAD OF THE NEXT FRONT...WILL BE ENOUGH TO KEEP
SLIGHT CHANCE TO CHANCE POPS ACROSS MAINLY NORTH GEORGIA THROUGH
THURSDAY AFTERNOON. BEHIND THIS BOUNDARY...MUCH COOLER
TEMPERATURES MOVE INTO THE AREA...WHICH WITH SOME RESIDUAL
MOISTURE...WILL BE ENOUGH TO PRODUCE LIGHT SNOW ACROSS NORTH
GEORGIA. HAVE GONE WITH GENERALLY SLIGHT CHANCE TO CHANCE LIGHT
SNOW ACROSS THE NORTHERNMOST TIER OF COUNTIES. MODELS ARE IN
FAIRLY GOOD AGREEMENT WITH THIS SOLUTION...AND DUE TO
INCONVENIENCES THAT MAY RESULT FROM THIS PRECIP...CONFIDENCE IS
HIGH ENOUGH TO GO AHEAD AND ISSUE THE WINTER WEATHER ADVISORY FOR
00Z TO 12Z FRIDAY. HPC WWD HAS THE AREA OUTLOOKED FOR 1 INCH OF
ACCUMULATIONS...AND HAVE GENERALLY SIDED MORE TOWARDS THE 0.5 TO 1
INCH RANGE...WITH THE HIGHER AMOUNTS IN THE HIGHER ELEVATIONS.
WITH WARM SURFACE TEMPERATURES...MOST OF THE ACCUMULATIONS WILL BE
ON THE ELEVATED SURFACES.
ADDITIONALLY...THE TIGHT PRESSURE GRADIENT OVER THE AREA RESULTING
FROM THESE SERIES OF SYSTEMS WILL ALLOW FOR STRONG TO GUSTY WINDS TO
IMPACT THE AREA ON THURSDAY. EXPECTING WINDS TO BE IN THE 15 TO 20
MPH RANGE...WITH GUSTS AS HIGH AS 35 MPH. HAVE ISSUED A WIND
ADVISORY FOR ALL OF NORTH AND CENTRAL GEORGIA FOR 10 AM THURSDAY
THROUGH MIDNIGHT.
ONCE THE COLD FRONT PUSHES THROUGH THE STATE THURSDAY...ASSOCIATED
PARENT LOW SWEEPS OVER NEW ENGLAND...AND PULLS ANY REMAINING WRAP
AROUND MOISTURE UP THE APPALACHIANS DURING THE DAY FRIDAY. SURFACE
HIGH PRESSURE BUILDS BACK INTO THE STATE...WITH DRY AND CHILLY
CONDITIONS PREVAILING ACROSS THE STATE.
MET OUT PERFORMED THE MAV ON THE TEMPERATURES YESTERDAY...AND EACH
HAS ITS STRENGTHS WITH THE CURRENT FORECAST...ONE BETTER ON
TEMPS...THE OTHER SEEMINGLY BETTER ON DEW POINTS. HAVE GENERALLY
GONE WITH A BLEND OF THE TWO...AND HEAVILY WEIGHTING THE LOCAL BIAS
NUMBERS. AS A RESULT...EXPECTING ONE LAST DAY WITH HIGHS IN THE MID
50S TO MID 60S ON THURSDAY. INFLUENCE OF THE COLD FRONT REALLY
PROMINENT ON FRIDAY MORNING AS TEMPS DROP INTO THE 20S AND LOW
30S...AND WITH HIGHS ONLY IN THE 40S FRIDAY AFTERNOON.
31
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED 254 PM EST WED JAN 11 2012/
SURFACE HIGH PRESSURE CONTROLS THE ENVIRONMENT THROUGH EARLY
WEEK...WITH DRY CONDITIONS PREVAILING...AND CHILLY TEMPERATURES
GRADUALLY WARMING. NEXT FRONTAL SYSTEM LOOKS TO MOVE INTO
NORTHWEST GEORGIA THROUGH EARLY TUESDAY. HAVE MADE NO MAJOR
CHANGES TO THE CURRENT FORECAST...AND SLIGHT CHANCE TO CHANCE POPS
ARE STILL EXPECTED TUESDAY AS THIS NEXT SYSTEM ENTERS THE REGION.
31
&&
.AVIATION...
06Z UPDATE...
EXPECT MVFR CIGS TO DOMINATE THROUGH MUCH OF THE PERIOD...THOUGH
MAY SEE A BRIEF PERIOD OF CIGS IN THE IFR RANGE 10Z TO 14Z TIME
FRAME. VSBYS GENERALLY UNRESTRICTED EXCEPT POSSIBLY LOWERING INTO
THE MVFR RANGE THIS AFTERNOON/EARLY EVENING IN SCATTERED LIGHT
SHOWERS AS A SECONDARY COLD FRONT MOVES ACROSS THE AREA. SOUTHWEST
WINDS 8 TO 12 KTS REST OF THE NIGHT...BECOMING MORE WESTERLY AND
INCREASING INTO THE 12 TO 18 KT RANGE BY MID MORNING THURSDAY WITH
GUSTS UP TO 30 KTS POSSIBLE IN THE AFTERNOON WITH THE FRONT MOVING
THROUGH.
//ATL CONFIDENCE...06Z UPDATE...
HIGH MOST ELEMENTS...EXCEPT MEDIUM ON THE DEVELOPMENT OF IFR CIGS
THIS MORNING.
49
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 28 47 24 / 20 10 0 5
ATLANTA 58 28 45 26 / 30 10 0 5
BLAIRSVILLE 50 23 37 18 / 50 30 0 5
CARTERSVILLE 57 29 43 20 / 30 20 0 5
COLUMBUS 64 29 49 27 / 20 5 0 5
GAINESVILLE 53 30 42 25 / 30 20 0 5
MACON 65 30 50 24 / 20 10 0 5
ROME 56 28 42 20 / 50 20 0 10
PEACHTREE CITY 59 26 46 20 / 20 10 0 5
VIDALIA 68 31 51 31 / 5 10 0 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THIS MORNING TO MIDNIGHT EST TONIGHT
FOR THE FOLLOWING ZONES: BALDWIN...BANKS...BARROW...BARTOW...
BIBB...BLECKLEY...BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...
CHATTOOGA...CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...
CRAWFORD...CRISP...DADE...DAWSON...DEKALB...DODGE...DOOLY...
DOUGLAS...EMANUEL...FANNIN...FAYETTE...FLOYD...FORSYTH...
GILMER...GLASCOCK...GORDON...GREENE...GWINNETT...HALL...
HANCOCK...HARALSON...HARRIS...HEARD...HENRY...HOUSTON...
JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...
LAURENS...LUMPKIN...MACON...MADISON...MARION...MERIWETHER...
MONROE...MONTGOMERY...MORGAN...MURRAY...MUSCOGEE...NEWTON...
NORTH FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...
PICKENS...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...SCHLEY...
SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TOWNS...TREUTLEN...
TROUP...TWIGGS...UNION...UPSON...WALKER...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WHITE...WHITFIELD...WILCOX...
WILKES...WILKINSON.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
FRIDAY FOR THE FOLLOWING ZONES: CATOOSA...DADE...FANNIN...
GILMER...LUMPKIN...MURRAY...TOWNS...UNION...WALKER...WHITE...
WHITFIELD.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
206 AM CST THU JAN 12 2012
.DISCUSSION...
840 PM CST
AN INITIAL ANALYSIS HAS BEEN MADE OF 00Z UPPER AIR DATA AS WELL AS
THE 12.00 NAM AND 11.21 SREF. HAVE MADE MODIFICATIONS TO THE START
TIME OF THE SNOWFALL WHERE CONFIDENCE HAS INCREASED...BUT THE
WINTER WEATHER ADVISORY START TIMES STILL LOOK VALID.
RIGHT NOW THE AREA IS NICELY LOCATED UNDER A WEDGE OF SUPPRESSION
AND DRY AIR BETWEEN THE LOW OVER THE OHIO RIVER VALLEY AND THE
INCOMING DIGGING TROUGH AND ARCTIC FRONT. THIS SHOULD HOLD FOR A
WHILE AND LATEST GUIDANCE HAS CAUGHT ONTO THIS WITH SLOWER
PROGRESSION OF THE POST-FRONTAL FORCING AND SNOW ACROSS IA AND
INTO WESTERN MO. THE SURFACE COLD FRONT WILL CONTINUE
EAST...TURNING WINDS NORTHWEST AND BRINGING THE TEMPERATURES DOWN.
ALREADY THE CLEARING HAS ALLOWED FOR COOLING...AND THERE IS ALMOST
NO DOUBT THAT PRECIPITATION TYPE ONSET WILL BE SNOW GIVEN THE
COOLING COLUMN. THE NAM/RUC FORCING AND HRRR REFLECTIVITY HAVE
FORCING FOR PRECIPITATION STILL WEST OF INTERSTATE 39 BY 12Z...AND
STILL WEST OF CHICAGOLAND BY 15Z. THE SREF ENSEMBLE MEMBERS ALSO
HAVE A TIGHTER PACKING THROUGH 15Z FOR INCREASED CONFIDENCE...AND
THIS PACKING IS ON A SLOWER SOLUTION. HAVE ADDED HIGHER TEMPORAL
RESOLUTION POPS TO BETTER DEFINE THE ONSET TIME.
A NICE -37C 500MB COLD POCKET ASSOCIATED WITH THE WESTERN TROUGH
WILL DIG SOUTHEAST INTO THE LATE MORNING AND THE PHASING OF THE
SYSTEMS WILL RAPIDLY BEGIN. LARGE SCALE OMEGA INCREASES ACROSS THE
AREA WITH SATURATION WORKING ITS WAY ACROSS CHICAGOLAND AND
NORTHWEST IN. SO ONSET IN CHICAGOLAND STILL LOOKS TO BE PRIOR TO
NOON...AND LIKELY BETWEEN 9 AM AND NOON FOR MUCH OF THE AREA. THE
AFTERNOON INTO THE EARLY EVENING FOR MOST OF THE FORECAST AREA
CONTINUES TO BE THE PERIOD MOST FAVORED FOR HEAVIER SNOW. THIS IS
BECAUSE OF 1. STRONGER UPPER LEVEL SUPPORT 2. THE TIGHTEST MID-
LEVEL THERMAL GRADIENT SUPPORTING TEMPORARY BURSTS OF
MODERATE/HEAVY ACTIVITY WITHIN BANDS 3. SNOW-TO-WATER EFFICIENCIES
INCREASING WITH A COOLING COLUMN AND DEEPER DENDRITIC
GROWTH...ESPECIALLY AFTER 3 PM...AND 4. LAKE ENHANCED SUPPORT INTO
NORTHWEST INDIANA /WHICH ACTUALLY CONTINUES INTO THE NIGHTTIME
HOURS. THIS IS THE AREA THAT WILL BE PARTICULARLY WATCHED FOR
POSSIBLE UPGRADE TO A WARNING IN TIME.
THE ONLY CHANGE WITH THE THURSDAY AFTERNOON PORTION OF THE
FORECAST WAS TO SLIGHTLY INCREASE SNOWFALL AMOUNTS SOUTH OF
INTERSTATE 80. AMOUNTS ON THURSDAY AFTERNOON ACROSS THE AREA COULD
BE PRETTY HOMOGENEOUS...WITH TEMPORARY BURSTS/BANDS SUPPORTING
LOCALIZED HIGHER AREAS. THE SLOWER ONSET TIME MAY MEAN LESS
SNOWFALL IN THE MORNING ACROSS THE SOUTH THOUGH...SO OVERALL
FORECAST AMOUNTS CAME OUT FAIRLY CLOSE...WITH NO CHANGES FOR
CHICAGOLAND ON TOTALS.
MTF
//PREV DISCUSSION...
243 PM CST
WINTER STORM...TONIGHT THROUGH FRIDAY NIGHT...
HAVE ISSUED WINTER WEATHER ADVISORIES FOR SNOW AND BLOWING SNOW
WHICH WILL COVER THE CAW FOR THURSDAY INTO EARLY FRIDAY.
STRONG SHORT WAVE TROUGH DIGGING SOUTHEAST ACROSS THE NORTHERN
PLAINS WILL CONTINUE TO CARVE OUT A DEEP UPPER TROUGH ACROSS THE
CENTRAL CONUS TONIGHT/THURSDAY...WITH A CLOSED UPPER LOW
DEVELOPING ACROSS THE MID-MISSISSIPPI VALLEY. PRE-EXISTING SURFACE
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND LIFT NORTH INTO
THE GREAT LAKES REGION IN RESPONSE TO DEVELOPING UPPER LOW...AND
STRONG LOW LEVEL BAROCLINICITY WITH INTRUSION OF LOW LEVEL ARCTIC
AIR. UPPER DIVERGENCE IN LEFT EXIT REGION OF CYCLONICALLY CURVED
UPPER JET STREAK WILL ALSO AID IN DEVELOPING DEEP SYNOPTIC SCALE
ASCENT ACROSS THE THE AREA. 12Z MODEL GUIDANCE IS GENERALLY IN
VERY GOOD AGREEMENT IN DEPICTION OF EVOLUTION OF SYSTEM OVER THE
NEXT 36 HOURS...SAVE FOR SOME QPF DIFFERENCES...WITH THE WRF-NAM
BEING MORE GENEROUS WITH THE PRECIP/SNOW AMOUNTS. GUIDANCE DOES
INDICATE THAT THE GREATEST AMOUNTS WILL LIKELY BE ACROSS NORTHEAST
IL/NORTHWEST INDIANA WHERE SOME LAKE-ENHANCEMENT POTENTIAL
EXISTS...AND WHERE LARGER SCALE DEFORMATION AXIS EVENTUALLY SETS
UP AS SYSTEM DEEPENS AND MOVES OFF TO THE EAST-NORTHEAST LATER
THURSDAY AND THURSDAY NIGHT. WHILE FORCING DECREASES QUICKLY LATE
THURSDAY NIGHT...LIGHTER SNOW/SNOW SHOWERS IS/ARE EXPECTED TO
CONTINUE INTO FRIDAY MORNING. THE PERIOD MOST FAVORABLE FOR MORE
SIGNIFICANT ACCUMULATION WILL SLIDE FROM WEST TO EAST ACROSS THE
AREA FROM MID THURSDAY MORNING THROUGH VERY EARLY FRIDAY EVENING.
SNOWFALL AMOUNTS ARE TRICKY WITH THIS SYSTEM...LARGELY DUE TO DEGREE
OF COOLING OF THE COLUMN AS DEPTH OF ARCTIC AIR INCREASES LATE
THURSDAY AND THURSDAY NIGHT...AS WELL AS DUE TO AFOREMENTIONED
POTENTIAL FOR LAKE-ENHANCEMENT IN COUNTIES BORDERING LAKE MICHIGAN.
MODEL SNOW/LIQUID RATIOS RANGE FROM 10:1 AT ONSET...TO 15 OR 20:1
LATER IN THE EVENT. HAVE GENERALLY USED HPC QPF...WITH A LITTLE
BLENDING OF WRF OUTPUT...AND RATIOS RANGING FROM 10:1 TO 17:1
THROUGH THE EVENT FOR SNOWFALL FORECAST. THIS YIELDS ROUGHLY 3-5
INCHES ACROSS SOUTHWESTERN CWA...TO 4-6 INCHES FOR NORTHEAST CWA
COUNTIES NOT ALONG THE LAKE...TO 4-8 INCHES FOR THE LAKE ADJOINING
COUNTIES. ACCUMULATING SNOWFALL IS EXPECTED TO BE OVER NEARLY A 24
HOUR PERIOD...THOUGH EXPECT IT WILL FALL JUST SHORT OF THE 6
INCHES IN 12 HOURS OR 8 INCHES IN 24 HOURS CRITERIA FOR WINTER
STORM WARNING. BASED ON THIS...AND COLLABORATION WITH MKX/ILX AND
IWX HAVE ELECTED TO ISSUE A WINTER WEATHER ADVISORY FOR SNOW AND
BLOWING SNOW. NORTHWEST WINDS ARE EXPECTED TO INCREASE TO 20-25
MPH THURSDAY AFTERNOON...AND MAY GUST 30-35 MPH THURSDAY NIGHT AS
LOW DEEPENS OFF TO OUR EAST. THIS WILL LIKELY RESULT IN
SIGNIFICANT BLOWING AND DRIFTING SNOW PARTICULARLY IN OPEN/RURAL
AREAS. IN ADDITION TO THE BLOWING/DRIFTING ISSUES...THESE WINDS
WILL COMBINE WITH ARCTIC AIR TO PRODUCE WIND CHILLS IN THE ZERO TO
-10 F RANGE THURSDAY NIGHT/EARLY FRIDAY MORNING.
THE POTENTIAL FOR LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO
NORTHWEST INDIANA ON FRIDAY...THOUGH FORECAST SOUNDINGS DEPICT WINDS
GRADUALLY BACKING MORE WEST-NORTHWEST WHICH SHOULD FORCE STRONGER
LAKE EFFECT BANDS INTO WFOS GRR/IWX AREAS.
RATZER
LONGER TERM...FRIDAY THROUGH EARLY NEXT WEEK...
THE CLOSED CIRCULATION ALOFT THAT WILL BRING THE BLAST OF WINTER
WEATHER WILL MOVE ACROSS THE NORTHEASTERN STATES BY THE AFTERNOON ON
FRIDAY. IN THE WAKE OF THIS SYSTEM WILL BE WEAK SURFACE RIDGING THAT
WILL FLIP WINDS BACK TO THE SOUTHWEST AND ADVECT IN A LITTLE WARMER
AIR FROM THE COLDER AIRMASS THAT WAS DUMPED ACROSS THE REGION. WHILE
STILL CHILLY...HIGHS WILL MANAGE TO GET WITHIN REACH OF NORMAL FOR
THIS TIME OF YEAR ON SATURDAY...WITH GENERALLY LOWER 30S EXPECTED
SOUTH OF I-80 AND TEMPS JUST BELOW NORMAL TO THE NORTH. INTO THE
EVENING ANOTHER CLIPPER WILL DIVE OUT OF THE NORTHERN PLAINS AND
ACROSS THE CWA THROUGH EARLY SUNDAY MORNING. THERE IS STILL A
LITTLE UNCERTAINTY WITH RESPECT TO THE TRACK OF THE CLIPPER MOVING
THROUGH...AS ALL GUIDANCE /ECMWF - GEMNH - GFS/ HAVE TRENDED A
LITTLE FURTHER SOUTH OVER THE LAST FEW RUNS...SO CONFIDENCE IS NOT
THE HIGHEST WITH THE LIKELIHOOD ON WHERE THE LOW WILL TRACK.
REGARDLESS...THE SYSTEM WILL MOVE THROUGH PRETTY QUICKLY AND ONLY
IMPACT THE CWA IN THE AFTERNOON TO EVENING HOURS WITH A LIGHT
DUSTING OF SNOW. DUE TO THE UNCERTAINTY...WILL MAINTAIN ONLY THE
MENTION OF CHANCE POPS AT THIS TIME BUT LEAN TOWARDS A LATER POINT
IN THE DAY FOR IT TO MOVE THROUGH. CONDITIONS WILL REMAIN NEAR TO
BELOW NORMAL TO CLOSE OUT THE WEEKEND.
RIDGING WILL THEN BUILD IN ON SUNDAY NIGHT AND INTO THE OPENING OF
NEXT WEEK ALLOWING TEMPERATURES TO CREEP UP TO ABOVE FREEZING
BUT...THERE IS SOME QUESTION AS TO HOW WARM IT WILL GET WITH SNOW
REMAINING ON THE GROUND THROUGH THAT TIME. NEXT UPPER LEVEL TROUGH
WILL SWING THROUGH MONDAY NIGHT INTO TUESDAY...LIFTING A SURFACE
FEATURE NORTHEAST THROUGH MICHIGAN INTO THAT TIME. PROFILES
SUGGEST THAT WITH THE MODERATE WARM AIR ADVECTION GOING ON...THAT
PTYPE WILL START AS RAIN BEFORE QUICKLY BECOMING SNOW AS THE
ENTIRE PROFILE DIPS BELOW FREEZING. THE ROLLER COASTER OF TEMPS
RISING AND FALLING WITH WEAK UPPER LEVEL DISTURBANCES ZIPPING
THROUGH ARE EXPECTED TO CONTINUE INTO NEXT WEEKEND.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* CEILINGS LOWING TO MVFR BY ARND 10Z...LOWERING TO IFR SHORTLY
AFTER THE SNOW ONSET.
* SNOW DEVELOPING BY ARND 16Z AND CONTINUING THROUGH THE
REMAINDER OF THE FORECAST PERIOD.
* VIS DROPPING TO IFR LIKELY SHORTLY AFTER SNOW ONSET. PERIODS OF
1/2SM VIS LIKELY FROM LATE AFTERNOON THROUGH THE EVENING WITH
INCREASING SNOWFALL RATES AND INCREASING WINDS.
* CHANCE OF VIS DROPPING TO 1/4SM OR LESS DURING THE EARLY EVENING
AS BLOWING SNOW DEVELOPS AS DECREASING TEMPERATURES CAUSE A
DRIER SNOW CHARACTERISTIC.
KREIN
//DISCUSSION...UPDATED 06Z...
NOT MUCH CHANGE FROM PREVIOUS THINKING.
THE FIRST APPRECIABLE WINTER WEATHER EVENT OF THE SEASON IS STILL
SET TO IMPACT THE TERMINALS FOR MUCH OF THE DAY ON THURSDAY AND INTO
THURSDAY NIGHT. THIS IS A RATHER COMPLEX AND DYNAMICAL STORM
SYSTEM THAT LOOKS TO BRING A PERIOD OF MODERATE TO HEAVY SNOW TO
THE NORTHEASTERN ILLINOIS TERMINALS DURING THE AFTERNOON AND
EVENING HOURS ON THURSDAY. THIS WILL BE THE MAIN CONCERN AS SNOW
AND BLOWING SNOW WILL LIKELY LEAD TO A PERIOD OF IFR TO LIFR VIS
AND CIGS THURSDAY AFTERNOON AND INTO THE EVENING.
THE MAIN COLD FRONT IS NOW MOVING ACROSS NORTH CENTRAL IL
NEAR KRFD. THIS FRONT SHOULD MOVE ACROSS NORTHEASTERN
ILLINOIS AFTER 07 UTC TONIGHT. BEHIND THIS FRONT...EXPECT WINDS TO
BECOME GUSTY OUT OF THE NORTHWEST. THE MAIN SURFACE LOW MOVING NORTH
ACROSS THE OHIO VALLEY LATE THIS EVENING...WILL QUICKLY INTENSIFY
DURING THE MORNING ON THURSDAY ACROSS THE GREAT LAKES REGION. THIS
WILL SET THE STAGE FOR GUSTY NORTHWEST WINDS THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
AS FAR AS SNOWFALL...IT APPEARS SNOWFALL WILL BEGIN DURING
THE MID TO LATE MORNING HOURS (AFTER 16 UTC AT THE NORTHEASTERN
ILLINOIS TERMINALS) AS STRONG FORCING FOR ASCENT COMMENCES IN
RESPONSE TO THE ATMOSPHERIC DYNAMICS OF THIS DEEPENING SURFACE
LOW. I EXPECT THE ONSET TIME TO OCCUR AROUND OR SHORTLY AFTER 12
UTC AT KRFD. THE SNOW SHOULD PICK UP IN INTENSITY DURING THE
AFTERNOON HOURS (AFTER 19 UTC) AS THE DYNAMICS REACH A PEAK ALONG
THE LEADING EDGE OF THE COLDEST AIR. THIS STILL APPEARS TO
POSSIBLY RESULT IN A PERIOD OF VISIBILITIES IN SNOW AND BLOWING
SNOW UNDER 1/2 MILE THROUGH THE AFTERNOON AND EARLY EVENING. THE
SNOWFALL SHOULD BEGIN TO ABATE LATER THURSDAY NIGHT INTO FRIDAY
MORNING AS THE STORM SYSTEM SHIFTS EAST ACROSS THE EASTERN GREAT
LAKES.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* HIGH CONFIDENCE WITH CEILING AND WIND TRENDS.
* HIGH CONFIDENCE OF SNOW WITH MEDIUM CONFIDENCE OF TIMING AND VIS
TRENDS ON THURSDAY.
* LOWER CONFIDENCE IN THE PROBABILITY OF VISIBILITY OCCASIONALLY
DROPPING TO 1/4SM OR LESS
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...IFR CIGS/VIS EARLY IN SNOW AND BLOWING SNOW. CONDITIONS
IMPROVING THROUGH THE DAY.
SATURDAY...CHANCE OF SNOW WITH MVFR CIGS/VIS.
SUNDAY...VFR.
MONDAY AND TUESDAY...CHANCE OF SNOW SHOWERS WITH MVFR CIGS/VIS.
KJB
&&
.MARINE...
145 PM CST
LOW PRESSURE OVER THE TENNESSEE VALLEY THIS AFTERNOON WILL CURVE
NORTHEAST INTO THE EASTERN GREAT LAKES AND INTENSIFY LATE TONIGHT
AND THURSDAY AS AN ARCTIC AIR MASS PLUNGES SOUTH FROM CENTRAL
CANADA AND THE NORTHERN PLAINS. LIGHT SOUTHEAST WINDS THIS
AFTERNOON WILL BACK NORTHEAST...THEN NORTHWEST AND INCREASE LATE
TONIGHT AND THURSDAY MORNING. WINDS WILL CONTINUE TO RAMP UP
THURSDAY WITH GALE FORCE WINDS OVER THE OPEN WATERS BY LATE
AFTERNOON. WITH WINDS OFFSHORE...WILL LIKELY STAY BELOW GALES FOR
THE ILLINOIS NEARSHORE...BUT EXPECT GALE FORCE WINDS ALONG THE
INDIANA NEARSHORE WATERS. GALES WILL LIKELY CONTINUE THROUGH
FRIDAY AFTERNOON AS THE LOW SPINS OVER THE LOWER LAKES FOR A WHILE
BEFORE MOVING EAST. HIGH PRESSURE WILL BRING DIMINISHING WINDS
LATE FRIDAY NIGHT AND SATURDAY MORNING. WEAK LOW PRESSURE MOVING
THROUGH THE MIDWEST SATURDAY AFTERNOON AND EVENING WILL HAVE
LITTLE IMPACT ON THE LAKE. AS HIGH PRESSURE MOVES EAST ACROSS THE
LAKES SUNDAY WINDS WILL VEER SOUTH THEN INCREASE SUNDAY NIGHT AND
MONDAY.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-
ILZ019-ILZ021-ILZ032...6 AM THURSDAY TO 4 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-
ILZ020-ILZ022-ILZ023-ILZ033-ILZ039...9 AM THURSDAY TO 9 AM
FRIDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...9
AM THURSDAY TO 9 AM FRIDAY.
LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM
THURSDAY TO 3 PM FRIDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...NOON
THURSDAY TO MIDNIGHT SATURDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...NOON THURSDAY TO 3 PM
THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1116 PM CST WED JAN 11 2012
.DISCUSSION...
ISSUED 845 PM CST WED JAN 11 2012
QUICK GLANCE AT THE 00Z NAM...AS WELL AS THE HRRR AND RUC MODELS...
INDICATES NO BIG CHANGES NEEDED TO HEADLINES OR SNOW SCENARIO
FORECAST. COLD FRONT NOW APPROACHING THE IL RIVER WITH GUSTY
NORTHWEST WINDS AND LOW CLOUDS. RADARS INDICATE THE SNOW IS LAGGING
BACK OVER CENTRAL IA...SO NO POPS THIS EVENING STILL LOOK ON TRACK.
THE NAM AND HRRR MODELS INDICATE THE LEADING EDGE OF THE SNOW
REACHING THE MIDDLE OF THE FORECAST AREA BY 12Z. WATER VAPOR LOOPS
SHOWING THE DEEPENING/AMPLIFYING TROUGH OVER THE PLAINS...WITH
INCREASING INFLECTION OVER NEB BEING THE BEGINNINGS OF THE LOW
CLOSING OFF. THE EXPANDING DARK AREA ON SATELLITE ALONG THE TROF
AXIS AND DOWN INTO THE INFLECTION OVER SOUTHERN NEB AND NORTHWESTERN
KS SUGGESTS THAT STRATOSPHERIC POTENTIAL VORTICITY IS POKING
DOWNWARD ON THE WESTERN FLANK OF THE TROUGH...WHICH WILL ACT TO
ACCELERATE THE DEEPENING PROCESS.
MOST OF THE SYNOPTIC MODEL OUTPUT AGREES ON TRACKING THE CENTER OF
THE DEEPENING UPPER LOW ACROSS THE SOUTHERN THIRD OF IL FROM LATE
MORNING TO LATE AFTERNOON THURSDAY. DURING THAT TIME...PV AND
DIFLUENCE WILL BE ROTATING THROUGH THE EASTERN QUADRANT AND INTO THE
NORTHEASTERN QUADRANT OF THE LOW...WHICH WILL EXTEND EAST/WEST
THROUGH CENTRAL IL. IN ADDITION...ISENTROPIC ANALYSES INDICATE A
DECENT UPGLIDE ON THE 300K-290K SURFACES IN THE SAME GENERAL
AREA...WITH SPECIFIC HUMIDITIES OF 1.5-2.5 G/KG. SO SNOW AMOUNTS OF
3-5 INCHES OVER THE NORTHERN HALF OF THE AREA STILL LOOK GOOD...WITH
POSSIBLE MESOSCALE ENHANCEMENT OF SNOW BANDS.
WILL FRESHEN UP THE WINTER WEATHER ADVISORY PRODUCT SHORTLY.
04
&&
.AVIATION...
ISSUED 1116 PM CST WED JAN 11 2012
UPPER LOW CONTINUES TO DEEPEN AS IT MOVES SOUTHEASTWARD ACROSS NEB.
THE LOW WILL MOVE THROUGH MO THEN ACROSS IL TO THE SOUTH OF THE TAF
SITES ON THURSDAY. COLD FRONT AHEAD OF THIS LOW HAS ALREADY MADE IT
THROUGH ALMOST ALL TERMINALS...AND IT IS NOT FAR FROM CMI. 15-25 KT
NORTHWESTERLY WINDS WILL INCREASE ON THURSDAY WITH GUSTS 30-35 KT.
MVFR 1K-2K FT STRATOCU IS CURRENTLY AN HOUR OR SO BEHIND THE
FRONT...BUT THE SNOW IS STILL LAGGING BACK IN EASTERN IA AND CENTRAL
MO. AT THE CURRENT RATE OF MOVEMENT...THE SNOW SHOULD BE MOVING INTO
THE PIA/SPI AREAS AROUND 12Z OR SHORTLY THEREAFTER. IFR CONDITIONS
OR LOWER IN SNOW/BLOWING SNOW WILL BE COMMON MUCH OF THURSDAY. SNOW
RATES WILL BE DECREASING SOMEWHAT AFTER 00Z FRI AS THE SYSTEM MOVES
OFF...BUT LOW CIGS AND LIGHT SNOW/BLOWING SNOW WILL CONTINUE THROUGH
AT LEAST 06Z.
04
&&
.PREV DISCUSSION...
ISSUED 220 PM CST WED JAN 11 2012
SNOW...WIND AND MUCH COLDER WEATHER HEADING FOR CENTRAL...EAST
CENTRAL AND SOUTHEAST ILLINOIS THURSDAY INTO FRIDAY.
SOUTHERN STREAM SHORTWAVE AND ASSOCIATED SURFACE LOW SOUTH OF THE
OHIO RIVER SPREAD RAIN AS FAR NORTH AS SPRINGFIELD EAST NORTHEAST TO
CHAMPAIGN. FURTHER NORTH AND WEST...SUNSHINE HAS BROUGHT EARLY
AFTERNOON TEMPERATURES INTO THE MID AND UPPER 50S. THE COLD FRONT
WHICH WILL BRING A DRASTIC CHANGE IN OUR WEATHER AS PUSHING THRU
CENTRAL IOWA EARLY THIS AFTERNOON WITH TEMPERATURES STRUGGLING THRU
THE SINGLE DIGITS AND LOW TEENS OVER THE DAKOTAS.
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
SNOW AMOUNTS...FALLING TEMPERATURES AND GUSTY WINDS THE MAIN FORECAST
CONCERN THROUGH LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING.
CONDITIONS ARE EXPECTED TO DETERIORATE RAPIDLY TOMORROW MORNING
WEST...AND OVER THE EAST BY EARLY AFTERNOON.
MODELS IN DECENT AGREEMENT WITH THE MOVEMENT OF THE SOUTHERN STREAM
UPPER LEVEL WAVE AS IT GETS ABSORBED BY THE STRONGER NORTHERN STREAM
ENERGY LATER TOMORROW WHICH IN EFFECT WILL PRODUCE A DEEPENING
SURFACE WAVE WHICH IS FORECAST TO TRACK NORTH INTO EASTERN LOWER
MICHIGAN BY 00Z FRIDAY. SNOW SHOULD TRACK INTO FAR WESTERN IL
BETWEEN 09Z AND 12Z AFFECTING THE MORNING COMMUTE MAINLY IN AREAS
WEST OF INTERSTATE 55 WITH LOCATIONS TO THE EAST SEEING THE SNOW
DEVELOP BY MID TO LATE MORNING. THE COMMUTE HOME TOMORROW EVENING
LOOKS TO BE A REAL MESS. NAM-WRF TIME HEIGHT CROSS SECTIONS SHOWING
THE BEST DEEP LAYERED MOISTURE AND OMEGA COINCIDENT WITH THE SNOW
GROWTH REGION TO BE OCCURRING FROM MID MORNING TO LATE AFTERNOON
WEST AND LATE MORNING INTO THE EVENING HOURS EAST. TEMPERATURES THRU
THE DAY WILL BE STEADY OR SLOWLY FALLING WITH FRIDAY MORNING LOWS IN
THE 10 TO 15 DEGREE RANGE.
LOOKING AT BOTH THE NAM AND GFS ISENTROPIC PROFILES AT 290K...SUGGEST
THE BEST ASCENT AND LOWEST PRESSURE DEFICITS OCCUR IN THE 00Z TO 06Z
TIME FRAME WITH THE BETTER LIFT SHIFTING OFF TO OUR EAST LATE
THURSDAY NIGHT/FRIDAY MORNING. MODELS SUGGEST SOME DECENT 850-500 MB
FRONTOGENETICAL FORCING COUPLED WITH WEAK STATIC STABILITY
INDICATING THE POTENTIAL FOR SOME BANDED SNOWFALL...ESPECIALLY
ACROSS OUR NORTH LATER TOMORROW MORNING INTO THE AFTERNOON HOURS.
SNOW RATIOS START OUT AT 13:1 BUT FORECAST SOUNDINGS SUGGEST 16:1 OR
EVEN GREATER TOWARDS LATE THU AFTN AND EVENING. HIGHEST SNOW AMOUNTS
CONTINUE TO BE ALONG AND NORTH OF I-74 WHERE 3 TO 5 INCHES WILL
OCCUR...WITH SOME LOCALLY HIGHER AMOUNTS POSSIBLE...ESPECIALLY IN
OUR FAR NORTHEASTERN AREAS. FURTHER SOUTH...TOTAL SNOW AMOUNTS LOOK
TO BE IN THE ORDER OF 1 TO 3 INCHES WITH AN INCH OR TWO ALONG AND
SOUTH OF I-70. ISSUED THE WINTER WEATHER ADVISORY EARLIER AND WILL
CONTINUE WITH IT ACROSS THE ENTIRE FORECAST AREA INTO FRIDAY
MORNING. AS THE SURFACE SYSTEM DEEPENS LATER TONIGHT INTO THUR...NW
WINDS WILL INCREASE TO BETWEEN 20 TO 25 MPH...WITH OCCASIONAL GUSTS
APPROACHING 35 MPH...PRODUCING QUITE A BIT OF BLOWING SNOW. WINDS
SHOULD GRADUALLY DECREASE FRIDAY MORNING AS THE LOW PULLS WELL OFF
TO OUR EAST. WIND CHILLS DROP INTO THE SINGLE DIGITS NORTHWEST BY
TOMORROW AFTN...AND DOWN TO BETWEEN -3 TO -8 FRIDAY MORNING.
TRANQUIL WEATHER WILL RETURN FRIDAY AFTN INTO FRIDAY NIGHT WITH SOME
RATHER NIPPY TEMPERATURES IN STORE FOR THE AREA...ESPECIALLY WITH A
FRESH SNOW PACK IN PLACE. WENT BELOW MOST GUID VALUES FRI NIGHT/SAT
MORNING WITH OUR NORTH SEEING SINGLE DIGITS FOR LOWS. HOWEVER...IF
OUR NEXT WEATHER SYSTEM TRACKING IN FROM THE NORTHWEST ON SATURDAY
IS QUICKER THAN WHAT MODELS INDICATE...CLOUDS MAY GET INTO THE AREA
FASTER WHICH WOULD HELP KEEP THE TEMPS UP. FOR NOW... WL GO WITH THE
COLDER LOWS EARLY SATURDAY MORNING. CLIPPER SYSTEM TRACKING QUICKLY
SOUTHEAST INTO THE AREA ON SATURDAY BRINGING A THREAT OF LIGHT SNOW
TO THE AREA...ESPECIALLY ACRS THE NORTHEAST HALF OF THE FORECAST
AREA. GFS AND ECMWF IS FURTHEST SOUTH WHICH WOULD BRING SOME LIGHT
ACCUMULATING SNOWS TO OUR NORTH...WHILE THE NAM WAS A BIT FURTHER
NORTH AND NOT NEARLY AS AGGRESSIVE WITH THE QPF. FOR NOW...WILL KEEP
LOW CHANCE POPS GOING ACRS THE NORTH AND EAST.
LONG TERM...SUNDAY THROUGH WEDNESDAY
UPPER LEVEL HEIGHTS REBOUND OVER THE MIDWEST SUNDAY INTO MONDAY
WHICH WILL SPELL WARMER WEATHER RETURNING TO THE AREA. DESPITE THE
SNOW COVER...WE SHOULD SEE AFTERNOON TEMPS PUSH BACK INTO THE UPPER
20S TO MIDDLE 30S ON SUNDAY...AND UPPER 30S TO MIDDLE 40S BY MONDAY
WITH INCREASING SOUTHERLY WINDS. OUR NEXT WEATHER SYSTEM LOOKS TO
AFFECT THE AREA LATE MONDAY INTO MONDAY NIGHT WITH TEMP PROFILES
WARM ENOUGH TO SUPPORT MOSTLY RAIN WITH POSSIBLY A CHANGEOVER TO
LIGHT SNOW OR FLURRIES AS THE SYSTEM PULLS AWAY AND COLDER AIR IS
DRAWN SOUTHEAST INTO OUR AREA ON TUES. AFTER A BRIEF SHOT OF COLD
AIR MIDWEEK...A MORE ZONAL FLOW PATTERN WILL DEVELOP ACROSS THE
LOWER 48 RESULTING IN TEMPS AOA NORMAL FOR THE REMAINDER OF THE WEEK.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO 9 AM CST FRIDAY
FOR ILZ038-043>046-052>057-061>063-066>068-071>073.
WINTER WEATHER ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY
FOR ILZ027>031-036-037-040>042-047>051.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1046 PM CST WED JAN 11 2012
.DISCUSSION...
840 PM CST
AN INITIAL ANALYSIS HAS BEEN MADE OF 00Z UPPER AIR DATA AS WELL AS
THE 12.00 NAM AND 11.21 SREF. HAVE MADE MODIFICATIONS TO THE START
TIME OF THE SNOWFALL WHERE CONFIDENCE HAS INCREASED...BUT THE
WINTER WEATHER ADVISORY START TIMES STILL LOOK VALID.
RIGHT NOW THE AREA IS NICELY LOCATED UNDER A WEDGE OF SUPPRESSION
AND DRY AIR BETWEEN THE LOW OVER THE OHIO RIVER VALLEY AND THE
INCOMING DIGGING TROUGH AND ARCTIC FRONT. THIS SHOULD HOLD FOR A
WHILE AND LATEST GUIDANCE HAS CAUGHT ONTO THIS WITH SLOWER
PROGRESSION OF THE POST-FRONTAL FORCING AND SNOW ACROSS IA AND
INTO WESTERN MO. THE SURFACE COLD FRONT WILL CONTINUE
EAST...TURNING WINDS NORTHWEST AND BRINGING THE TEMPERATURES DOWN.
ALREADY THE CLEARING HAS ALLOWED FOR COOLING...AND THERE IS ALMOST
NO DOUBT THAT PRECIPITATION TYPE ONSET WILL BE SNOW GIVEN THE
COOLING COLUMN. THE NAM/RUC FORCING AND HRRR REFLECTIVITY HAVE
FORCING FOR PRECIPITATION STILL WEST OF INTERSTATE 39 BY 12Z...AND
STILL WEST OF CHICAGOLAND BY 15Z. THE SREF ENSEMBLE MEMBERS ALSO
HAVE A TIGHTER PACKING THROUGH 15Z FOR INCREASED CONFIDENCE...AND
THIS PACKING IS ON A SLOWER SOLUTION. HAVE ADDED HIGHER TEMPORAL
RESOLUTION POPS TO BETTER DEFINE THE ONSET TIME.
A NICE -37C 500MB COLD POCKET ASSOCIATED WITH THE WESTERN TROUGH
WILL DIG SOUTHEAST INTO THE LATE MORNING AND THE PHASING OF THE
SYSTEMS WILL RAPIDLY BEGIN. LARGE SCALE OMEGA INCREASES ACROSS THE
AREA WITH SATURATION WORKING ITS WAY ACROSS CHICAGOLAND AND
NORTHWEST IN. SO ONSET IN CHICAGOLAND STILL LOOKS TO BE PRIOR TO
NOON...AND LIKELY BETWEEN 9 AM AND NOON FOR MUCH OF THE AREA. THE
AFTERNOON INTO THE EARLY EVENING FOR MOST OF THE FORECAST AREA
CONTINUES TO BE THE PERIOD MOST FAVORED FOR HEAVIER SNOW. THIS IS
BECAUSE OF 1. STRONGER UPPER LEVEL SUPPORT 2. THE TIGHTEST MID-
LEVEL THERMAL GRADIENT SUPPORTING TEMPORARY BURSTS OF
MODERATE/HEAVY ACTIVITY WITHIN BANDS 3. SNOW-TO-WATER EFFICIENCIES
INCREASING WITH A COOLING COLUMN AND DEEPER DENDRITIC
GROWTH...ESPECIALLY AFTER 3 PM...AND 4. LAKE ENHANCED SUPPORT INTO
NORTHWEST INDIANA /WHICH ACTUALLY CONTINUES INTO THE NIGHTTIME
HOURS. THIS IS THE AREA THAT WILL BE PARTICULARLY WATCHED FOR
POSSIBLE UPGRADE TO A WARNING IN TIME.
THE ONLY CHANGE WITH THE THURSDAY AFTERNOON PORTION OF THE
FORECAST WAS TO SLIGHTLY INCREASE SNOWFALL AMOUNTS SOUTH OF
INTERSTATE 80. AMOUNTS ON THURSDAY AFTERNOON ACROSS THE AREA COULD
BE PRETTY HOMOGENEOUS...WITH TEMPORARY BURSTS/BANDS SUPPORTING
LOCALIZED HIGHER AREAS. THE SLOWER ONSET TIME MAY MEAN LESS
SNOWFALL IN THE MORNING ACROSS THE SOUTH THOUGH...SO OVERALL
FORECAST AMOUNTS CAME OUT FAIRLY CLOSE...WITH NO CHANGES FOR
CHICAGOLAND ON TOTALS.
MTF
//PREV DISCUSSION...
243 PM CST
WINTER STORM...TONIGHT THROUGH FRIDAY NIGHT...
HAVE ISSUED WINTER WEATHER ADVISORIES FOR SNOW AND BLOWING SNOW
WHICH WILL COVER THE CAW FOR THURSDAY INTO EARLY FRIDAY.
STRONG SHORT WAVE TROUGH DIGGING SOUTHEAST ACROSS THE NORTHERN
PLAINS WILL CONTINUE TO CARVE OUT A DEEP UPPER TROUGH ACROSS THE
CENTRAL CONUS TONIGHT/THURSDAY...WITH A CLOSED UPPER LOW
DEVELOPING ACROSS THE MID-MISSISSIPPI VALLEY. PRE-EXISTING SURFACE
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND LIFT NORTH INTO
THE GREAT LAKES REGION IN RESPONSE TO DEVELOPING UPPER LOW...AND
STRONG LOW LEVEL BAROCLINICITY WITH INTRUSION OF LOW LEVEL ARCTIC
AIR. UPPER DIVERGENCE IN LEFT EXIT REGION OF CYCLONICALLY CURVED
UPPER JET STREAK WILL ALSO AID IN DEVELOPING DEEP SYNOPTIC SCALE
ASCENT ACROSS THE THE AREA. 12Z MODEL GUIDANCE IS GENERALLY IN
VERY GOOD AGREEMENT IN DEPICTION OF EVOLUTION OF SYSTEM OVER THE
NEXT 36 HOURS...SAVE FOR SOME QPF DIFFERENCES...WITH THE WRF-NAM
BEING MORE GENEROUS WITH THE PRECIP/SNOW AMOUNTS. GUIDANCE DOES
INDICATE THAT THE GREATEST AMOUNTS WILL LIKELY BE ACROSS NORTHEAST
IL/NORTHWEST INDIANA WHERE SOME LAKE-ENHANCEMENT POTENTIAL
EXISTS...AND WHERE LARGER SCALE DEFORMATION AXIS EVENTUALLY SETS
UP AS SYSTEM DEEPENS AND MOVES OFF TO THE EAST-NORTHEAST LATER
THURSDAY AND THURSDAY NIGHT. WHILE FORCING DECREASES QUICKLY LATE
THURSDAY NIGHT...LIGHTER SNOW/SNOW SHOWERS IS/ARE EXPECTED TO
CONTINUE INTO FRIDAY MORNING. THE PERIOD MOST FAVORABLE FOR MORE
SIGNIFICANT ACCUMULATION WILL SLIDE FROM WEST TO EAST ACROSS THE
AREA FROM MID THURSDAY MORNING THROUGH VERY EARLY FRIDAY EVENING.
SNOWFALL AMOUNTS ARE TRICKY WITH THIS SYSTEM...LARGELY DUE TO DEGREE
OF COOLING OF THE COLUMN AS DEPTH OF ARCTIC AIR INCREASES LATE
THURSDAY AND THURSDAY NIGHT...AS WELL AS DUE TO AFOREMENTIONED
POTENTIAL FOR LAKE-ENHANCEMENT IN COUNTIES BORDERING LAKE MICHIGAN.
MODEL SNOW/LIQUID RATIOS RANGE FROM 10:1 AT ONSET...TO 15 OR 20:1
LATER IN THE EVENT. HAVE GENERALLY USED HPC QPF...WITH A LITTLE
BLENDING OF WRF OUTPUT...AND RATIOS RANGING FROM 10:1 TO 17:1
THROUGH THE EVENT FOR SNOWFALL FORECAST. THIS YIELDS ROUGHLY 3-5
INCHES ACROSS SOUTHWESTERN CWA...TO 4-6 INCHES FOR NORTHEAST CWA
COUNTIES NOT ALONG THE LAKE...TO 4-8 INCHES FOR THE LAKE ADJOINING
COUNTIES. ACCUMULATING SNOWFALL IS EXPECTED TO BE OVER NEARLY A 24
HOUR PERIOD...THOUGH EXPECT IT WILL FALL JUST SHORT OF THE 6
INCHES IN 12 HOURS OR 8 INCHES IN 24 HOURS CRITERIA FOR WINTER
STORM WARNING. BASED ON THIS...AND COLLABORATION WITH MKX/ILX AND
IWX HAVE ELECTED TO ISSUE A WINTER WEATHER ADVISORY FOR SNOW AND
BLOWING SNOW. NORTHWEST WINDS ARE EXPECTED TO INCREASE TO 20-25
MPH THURSDAY AFTERNOON...AND MAY GUST 30-35 MPH THURSDAY NIGHT AS
LOW DEEPENS OFF TO OUR EAST. THIS WILL LIKELY RESULT IN
SIGNIFICANT BLOWING AND DRIFTING SNOW PARTICULARLY IN OPEN/RURAL
AREAS. IN ADDITION TO THE BLOWING/DRIFTING ISSUES...THESE WINDS
WILL COMBINE WITH ARCTIC AIR TO PRODUCE WIND CHILLS IN THE ZERO TO
-10 F RANGE THURSDAY NIGHT/EARLY FRIDAY MORNING.
THE POTENTIAL FOR LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO
NORTHWEST INDIANA ON FRIDAY...THOUGH FORECAST SOUNDINGS DEPICT WINDS
GRADUALLY BACKING MORE WEST-NORTHWEST WHICH SHOULD FORCE STRONGER
LAKE EFFECT BANDS INTO WFOS GRR/IWX AREAS.
RATZER
LONGER TERM...FRIDAY THROUGH EARLY NEXT WEEK...
THE CLOSED CIRCULATION ALOFT THAT WILL BRING THE BLAST OF WINTER
WEATHER WILL MOVE ACROSS THE NORTHEASTERN STATES BY THE AFTERNOON ON
FRIDAY. IN THE WAKE OF THIS SYSTEM WILL BE WEAK SURFACE RIDGING THAT
WILL FLIP WINDS BACK TO THE SOUTHWEST AND ADVECT IN A LITTLE WARMER
AIR FROM THE COLDER AIRMASS THAT WAS DUMPED ACROSS THE REGION. WHILE
STILL CHILLY...HIGHS WILL MANAGE TO GET WITHIN REACH OF NORMAL FOR
THIS TIME OF YEAR ON SATURDAY...WITH GENERALLY LOWER 30S EXPECTED
SOUTH OF I-80 AND TEMPS JUST BELOW NORMAL TO THE NORTH. INTO THE
EVENING ANOTHER CLIPPER WILL DIVE OUT OF THE NORTHERN PLAINS AND
ACROSS THE CWA THROUGH EARLY SUNDAY MORNING. THERE IS STILL A
LITTLE UNCERTAINTY WITH RESPECT TO THE TRACK OF THE CLIPPER MOVING
THROUGH...AS ALL GUIDANCE /ECMWF - GEMNH - GFS/ HAVE TRENDED A
LITTLE FURTHER SOUTH OVER THE LAST FEW RUNS...SO CONFIDENCE IS NOT
THE HIGHEST WITH THE LIKELIHOOD ON WHERE THE LOW WILL TRACK.
REGARDLESS...THE SYSTEM WILL MOVE THROUGH PRETTY QUICKLY AND ONLY
IMPACT THE CWA IN THE AFTERNOON TO EVENING HOURS WITH A LIGHT
DUSTING OF SNOW. DUE TO THE UNCERTAINTY...WILL MAINTAIN ONLY THE
MENTION OF CHANCE POPS AT THIS TIME BUT LEAN TOWARDS A LATER POINT
IN THE DAY FOR IT TO MOVE THROUGH. CONDITIONS WILL REMAIN NEAR TO
BELOW NORMAL TO CLOSE OUT THE WEEKEND.
RIDGING WILL THEN BUILD IN ON SUNDAY NIGHT AND INTO THE OPENING OF
NEXT WEEK ALLOWING TEMPERATURES TO CREEP UP TO ABOVE FREEZING
BUT...THERE IS SOME QUESTION AS TO HOW WARM IT WILL GET WITH SNOW
REMAINING ON THE GROUND THROUGH THAT TIME. NEXT UPPER LEVEL TROUGH
WILL SWING THROUGH MONDAY NIGHT INTO TUESDAY...LIFTING A SURFACE
FEATURE NORTHEAST THROUGH MICHIGAN INTO THAT TIME. PROFILES
SUGGEST THAT WITH THE MODERATE WARM AIR ADVECTION GOING ON...THAT
PTYPE WILL START AS RAIN BEFORE QUICKLY BECOMING SNOW AS THE
ENTIRE PROFILE DIPS BELOW FREEZING. THE ROLLER COASTER OF TEMPS
RISING AND FALLING WITH WEAK UPPER LEVEL DISTURBANCES ZIPPING
THROUGH ARE EXPECTED TO CONTINUE INTO NEXT WEEKEND.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LOWERING CEILINGS LATE TONIGHT/EARLY THURSDAY MORNING...WITH
MVFR CEILINGS BECOMING IFR ON THURSDAY.
* SNOW DEVELOPING BY MID TO LATE THURSDAY MORNING AND CONTINUING
THROUGH THE REMAINDER OF THE FORECAST PERIOD.
* LIKELY A SEVERAL HOUR PERIOD OF IFR TO LIFR VIS THURSDAY
AFTERNOON INTO THE EVENING IN SNOW AND BLOWING SNOW.
KJB
//DISCUSSION...UPDATED 06Z...
NOT MUCH CHANGE FROM PREVIOUS THINKING.
THE FIRST APPRECIABLE WINTER WEATHER EVENT OF THE SEASON IS STILL
SET TO IMPACT THE TERMINALS FOR MUCH OF THE DAY ON THURSDAY AND INTO
THURSDAY NIGHT. THIS IS A RATHER COMPLEX AND DYNAMICAL STORM
SYSTEM THAT LOOKS TO BRING A PERIOD OF MODERATE TO HEAVY SNOW TO
THE NORTHEASTERN ILLINOIS TERMINALS DURING THE AFTERNOON AND
EVENING HOURS ON THURSDAY. THIS WILL BE THE MAIN CONCERN AS SNOW
AND BLOWING SNOW WILL LIKELY LEAD TO A PERIOD OF IFR TO LIFR VIS
AND CIGS THURSDAY AFTERNOON AND INTO THE EVENING.
THE MAIN COLD FRONT IS NOW MOVING ACROSS NORTH CENTRAL IL
NEAR KRFD. THIS FRONT SHOULD MOVE ACROSS NORTHEASTERN
ILLINOIS AFTER 07 UTC TONIGHT. BEHIND THIS FRONT...EXPECT WINDS TO
BECOME GUSTY OUT OF THE NORTHWEST. THE MAIN SURFACE LOW MOVING NORTH
ACROSS THE OHIO VALLEY LATE THIS EVENING...WILL QUICKLY INTENSIFY
DURING THE MORNING ON THURSDAY ACROSS THE GREAT LAKES REGION. THIS
WILL SET THE STAGE FOR GUSTY NORTHWEST WINDS THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
AS FAR AS SNOWFALL...IT APPEARS SNOWFALL WILL BEGIN DURING
THE MID TO LATE MORNING HOURS (AFTER 16 UTC AT THE NORTHEASTERN
ILLINOIS TERMINALS) AS STRONG FORCING FOR ASCENT COMMENCES IN
RESPONSE TO THE ATMOSPHERIC DYNAMICS OF THIS DEEPENING SURFACE
LOW. I EXPECT THE ONSET TIME TO OCCUR AROUND OR SHORTLY AFTER 12
UTC AT KRFD. THE SNOW SHOULD PICK UP IN INTENSITY DURING THE
AFTERNOON HOURS (AFTER 19 UTC) AS THE DYNAMICS REACH A PEAK ALONG
THE LEADING EDGE OF THE COLDEST AIR. THIS STILL APPEARS TO
POSSIBLY RESULT IN A PERIOD OF VISIBILITIES IN SNOW AND BLOWING
SNOW UNDER 1/2 MILE THROUGH THE AFTERNOON AND EARLY EVENING. THE
SNOWFALL SHOULD BEGIN TO ABATE LATER THURSDAY NIGHT INTO FRIDAY
MORNING AS THE STORM SYSTEM SHIFTS EAST ACROSS THE EASTERN GREAT
LAKES.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH CEILINGS AND TRENDS LATE TONIGHT/EARLY
THURSDAY.
* HIGH CONFIDENCE OF SNOW WITH MEDIUM CONFIDENCE OF TIMING AND VIS
TRENDS ON THURSDAY.
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...IFR CIGS/VIS EARLY IN SNOW AND BLOWING SNOW. CONDITIONS
IMPROVING THROUGH THE DAY.
SATURDAY...CHANCE OF SNOW WITH MVFR CIGS/VIS.
SUNDAY...VFR.
MONDAY AND TUESDAY...CHANCE OF SNOW SHOWERS WITH MVFR CIGS/VIS.
KJB
&&
.MARINE...
145 PM CST
LOW PRESSURE OVER THE TENNESSEE VALLEY THIS AFTERNOON WILL CURVE
NORTHEAST INTO THE EASTERN GREAT LAKES AND INTENSIFY LATE TONIGHT
AND THURSDAY AS AN ARCTIC AIR MASS PLUNGES SOUTH FROM CENTRAL
CANADA AND THE NORTHERN PLAINS. LIGHT SOUTHEAST WINDS THIS
AFTERNOON WILL BACK NORTHEAST...THEN NORTHWEST AND INCREASE LATE
TONIGHT AND THURSDAY MORNING. WINDS WILL CONTINUE TO RAMP UP
THURSDAY WITH GALE FORCE WINDS OVER THE OPEN WATERS BY LATE
AFTERNOON. WITH WINDS OFFSHORE...WILL LIKELY STAY BELOW GALES FOR
THE ILLINOIS NEARSHORE...BUT EXPECT GALE FORCE WINDS ALONG THE
INDIANA NEARSHORE WATERS. GALES WILL LIKELY CONTINUE THROUGH
FRIDAY AFTERNOON AS THE LOW SPINS OVER THE LOWER LAKES FOR A WHILE
BEFORE MOVING EAST. HIGH PRESSURE WILL BRING DIMINISHING WINDS
LATE FRIDAY NIGHT AND SATURDAY MORNING. WEAK LOW PRESSURE MOVING
THROUGH THE MIDWEST SATURDAY AFTERNOON AND EVENING WILL HAVE
LITTLE IMPACT ON THE LAKE. AS HIGH PRESSURE MOVES EAST ACROSS THE
LAKES SUNDAY WINDS WILL VEER SOUTH THEN INCREASE SUNDAY NIGHT AND
MONDAY.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-
ILZ019-ILZ021-ILZ032...6 AM THURSDAY TO 4 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-
ILZ020-ILZ022-ILZ023-ILZ033-ILZ039...9 AM THURSDAY TO 9 AM
FRIDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...9
AM THURSDAY TO 9 AM FRIDAY.
LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM
THURSDAY TO 3 PM FRIDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...NOON
THURSDAY TO MIDNIGHT SATURDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...NOON THURSDAY TO 3 PM
THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1007 PM CST WED JAN 11 2012
.DISCUSSION...
840 PM CST
AN INITIAL ANALYSIS HAS BEEN MADE OF 00Z UPPER AIR DATA AS WELL AS
THE 12.00 NAM AND 11.21 SREF. HAVE MADE MODIFICATIONS TO THE START
TIME OF THE SNOWFALL WHERE CONFIDENCE HAS INCREASED...BUT THE
WINTER WEATHER ADVISORY START TIMES STILL LOOK VALID.
RIGHT NOW THE AREA IS NICELY LOCATED UNDER A WEDGE OF SUPPRESSION
AND DRY AIR BETWEEN THE LOW OVER THE OHIO RIVER VALLEY AND THE
INCOMING DIGGING TROUGH AND ARCTIC FRONT. THIS SHOULD HOLD FOR A
WHILE AND LATEST GUIDANCE HAS CAUGHT ONTO THIS WITH SLOWER
PROGRESSION OF THE POST-FRONTAL FORCING AND SNOW ACROSS IA AND
INTO WESTERN MO. THE SURFACE COLD FRONT WILL CONTINUE
EAST...TURNING WINDS NORTHWEST AND BRINGING THE TEMPERATURES DOWN.
ALREADY THE CLEARING HAS ALLOWED FOR COOLING...AND THERE IS ALMOST
NO DOUBT THAT PRECIPITATION TYPE ONSET WILL BE SNOW GIVEN THE
COOLING COLUMN. THE NAM/RUC FORCING AND HRRR REFLECTIVITY HAVE
FORCING FOR PRECIPITATION STILL WEST OF INTERSTATE 39 BY 12Z...AND
STILL WEST OF CHICAGOLAND BY 15Z. THE SREF ENSEMBLE MEMBERS ALSO
HAVE A TIGHTER PACKING THROUGH 15Z FOR INCREASED CONFIDENCE...AND
THIS PACKING IS ON A SLOWER SOLUTION. HAVE ADDED HIGHER TEMPORAL
RESOLUTION POPS TO BETTER DEFINE THE ONSET TIME.
A NICE -37C 500MB COLD POCKET ASSOCIATED WITH THE WESTERN TROUGH
WILL DIG SOUTHEAST INTO THE LATE MORNING AND THE PHASING OF THE
SYSTEMS WILL RAPIDLY BEGIN. LARGE SCALE OMEGA INCREASES ACROSS THE
AREA WITH SATURATION WORKING ITS WAY ACROSS CHICAGOLAND AND
NORTHWEST IN. SO ONSET IN CHICAGOLAND STILL LOOKS TO BE PRIOR TO
NOON...AND LIKELY BETWEEN 9 AM AND NOON FOR MUCH OF THE AREA. THE
AFTERNOON INTO THE EARLY EVENING FOR MOST OF THE FORECAST AREA
CONTINUES TO BE THE PERIOD MOST FAVORED FOR HEAVIER SNOW. THIS IS
BECAUSE OF 1. STRONGER UPPER LEVEL SUPPORT 2. THE TIGHTEST MID-
LEVEL THERMAL GRADIENT SUPPORTING TEMPORARY BURSTS OF
MODERATE/HEAVY ACTIVITY WITHIN BANDS 3. SNOW-TO-WATER EFFICIENCIES
INCREASING WITH A COOLING COLUMN AND DEEPER DENDRITIC
GROWTH...ESPECIALLY AFTER 3 PM...AND 4. LAKE ENHANCED SUPPORT INTO
NORTHWEST INDIANA /WHICH ACTUALLY CONTINUES INTO THE NIGHTTIME
HOURS. THIS IS THE AREA THAT WILL BE PARTICULARLY WATCHED FOR
POSSIBLE UPGRADE TO A WARNING IN TIME.
THE ONLY CHANGE WITH THE THURSDAY AFTERNOON PORTION OF THE
FORECAST WAS TO SLIGHTLY INCREASE SNOWFALL AMOUNTS SOUTH OF
INTERSTATE 80. AMOUNTS ON THURSDAY AFTERNOON ACROSS THE AREA COULD
BE PRETTY HOMOGENEOUS...WITH TEMPORARY BURSTS/BANDS SUPPORTING
LOCALIZED HIGHER AREAS. THE SLOWER ONSET TIME MAY MEAN LESS
SNOWFALL IN THE MORNING ACROSS THE SOUTH THOUGH...SO OVERALL
FORECAST AMOUNTS CAME OUT FAIRLY CLOSE...WITH NO CHANGES FOR
CHICAGOLAND ON TOTALS.
MTF
//PREV DISCUSSION...
243 PM CST
WINTER STORM...TONIGHT THROUGH FRIDAY NIGHT...
HAVE ISSUED WINTER WEATHER ADVISORIES FOR SNOW AND BLOWING SNOW
WHICH WILL COVER THE CAW FOR THURSDAY INTO EARLY FRIDAY.
STRONG SHORT WAVE TROUGH DIGGING SOUTHEAST ACROSS THE NORTHERN
PLAINS WILL CONTINUE TO CARVE OUT A DEEP UPPER TROUGH ACROSS THE
CENTRAL CONUS TONIGHT/THURSDAY...WITH A CLOSED UPPER LOW
DEVELOPING ACROSS THE MID-MISSISSIPPI VALLEY. PRE-EXISTING SURFACE
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND LIFT NORTH INTO
THE GREAT LAKES REGION IN RESPONSE TO DEVELOPING UPPER LOW...AND
STRONG LOW LEVEL BAROCLINICITY WITH INTRUSION OF LOW LEVEL ARCTIC
AIR. UPPER DIVERGENCE IN LEFT EXIT REGION OF CYCLONICALLY CURVED
UPPER JET STREAK WILL ALSO AID IN DEVELOPING DEEP SYNOPTIC SCALE
ASCENT ACROSS THE THE AREA. 12Z MODEL GUIDANCE IS GENERALLY IN
VERY GOOD AGREEMENT IN DEPICTION OF EVOLUTION OF SYSTEM OVER THE
NEXT 36 HOURS...SAVE FOR SOME QPF DIFFERENCES...WITH THE WRF-NAM
BEING MORE GENEROUS WITH THE PRECIP/SNOW AMOUNTS. GUIDANCE DOES
INDICATE THAT THE GREATEST AMOUNTS WILL LIKELY BE ACROSS NORTHEAST
IL/NORTHWEST INDIANA WHERE SOME LAKE-ENHANCEMENT POTENTIAL
EXISTS...AND WHERE LARGER SCALE DEFORMATION AXIS EVENTUALLY SETS
UP AS SYSTEM DEEPENS AND MOVES OFF TO THE EAST-NORTHEAST LATER
THURSDAY AND THURSDAY NIGHT. WHILE FORCING DECREASES QUICKLY LATE
THURSDAY NIGHT...LIGHTER SNOW/SNOW SHOWERS IS/ARE EXPECTED TO
CONTINUE INTO FRIDAY MORNING. THE PERIOD MOST FAVORABLE FOR MORE
SIGNIFICANT ACCUMULATION WILL SLIDE FROM WEST TO EAST ACROSS THE
AREA FROM MID THURSDAY MORNING THROUGH VERY EARLY FRIDAY EVENING.
SNOWFALL AMOUNTS ARE TRICKY WITH THIS SYSTEM...LARGELY DUE TO DEGREE
OF COOLING OF THE COLUMN AS DEPTH OF ARCTIC AIR INCREASES LATE
THURSDAY AND THURSDAY NIGHT...AS WELL AS DUE TO AFOREMENTIONED
POTENTIAL FOR LAKE-ENHANCEMENT IN COUNTIES BORDERING LAKE MICHIGAN.
MODEL SNOW/LIQUID RATIOS RANGE FROM 10:1 AT ONSET...TO 15 OR 20:1
LATER IN THE EVENT. HAVE GENERALLY USED HPC QPF...WITH A LITTLE
BLENDING OF WRF OUTPUT...AND RATIOS RANGING FROM 10:1 TO 17:1
THROUGH THE EVENT FOR SNOWFALL FORECAST. THIS YIELDS ROUGHLY 3-5
INCHES ACROSS SOUTHWESTERN CWA...TO 4-6 INCHES FOR NORTHEAST CWA
COUNTIES NOT ALONG THE LAKE...TO 4-8 INCHES FOR THE LAKE ADJOINING
COUNTIES. ACCUMULATING SNOWFALL IS EXPECTED TO BE OVER NEARLY A 24
HOUR PERIOD...THOUGH EXPECT IT WILL FALL JUST SHORT OF THE 6
INCHES IN 12 HOURS OR 8 INCHES IN 24 HOURS CRITERIA FOR WINTER
STORM WARNING. BASED ON THIS...AND COLLABORATION WITH MKX/ILX AND
IWX HAVE ELECTED TO ISSUE A WINTER WEATHER ADVISORY FOR SNOW AND
BLOWING SNOW. NORTHWEST WINDS ARE EXPECTED TO INCREASE TO 20-25
MPH THURSDAY AFTERNOON...AND MAY GUST 30-35 MPH THURSDAY NIGHT AS
LOW DEEPENS OFF TO OUR EAST. THIS WILL LIKELY RESULT IN
SIGNIFICANT BLOWING AND DRIFTING SNOW PARTICULARLY IN OPEN/RURAL
AREAS. IN ADDITION TO THE BLOWING/DRIFTING ISSUES...THESE WINDS
WILL COMBINE WITH ARCTIC AIR TO PRODUCE WIND CHILLS IN THE ZERO TO
-10 F RANGE THURSDAY NIGHT/EARLY FRIDAY MORNING.
THE POTENTIAL FOR LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO
NORTHWEST INDIANA ON FRIDAY...THOUGH FORECAST SOUNDINGS DEPICT WINDS
GRADUALLY BACKING MORE WEST-NORTHWEST WHICH SHOULD FORCE STRONGER
LAKE EFFECT BANDS INTO WFOS GRR/IWX AREAS.
RATZER
LONGER TERM...FRIDAY THROUGH EARLY NEXT WEEK...
THE CLOSED CIRCULATION ALOFT THAT WILL BRING THE BLAST OF WINTER
WEATHER WILL MOVE ACROSS THE NORTHEASTERN STATES BY THE AFTERNOON ON
FRIDAY. IN THE WAKE OF THIS SYSTEM WILL BE WEAK SURFACE RIDGING THAT
WILL FLIP WINDS BACK TO THE SOUTHWEST AND ADVECT IN A LITTLE WARMER
AIR FROM THE COLDER AIRMASS THAT WAS DUMPED ACROSS THE REGION. WHILE
STILL CHILLY...HIGHS WILL MANAGE TO GET WITHIN REACH OF NORMAL FOR
THIS TIME OF YEAR ON SATURDAY...WITH GENERALLY LOWER 30S EXPECTED
SOUTH OF I-80 AND TEMPS JUST BELOW NORMAL TO THE NORTH. INTO THE
EVENING ANOTHER CLIPPER WILL DIVE OUT OF THE NORTHERN PLAINS AND
ACROSS THE CWA THROUGH EARLY SUNDAY MORNING. THERE IS STILL A
LITTLE UNCERTAINTY WITH RESPECT TO THE TRACK OF THE CLIPPER MOVING
THROUGH...AS ALL GUIDANCE /ECMWF - GEMNH - GFS/ HAVE TRENDED A
LITTLE FURTHER SOUTH OVER THE LAST FEW RUNS...SO CONFIDENCE IS NOT
THE HIGHEST WITH THE LIKELIHOOD ON WHERE THE LOW WILL TRACK.
REGARDLESS...THE SYSTEM WILL MOVE THROUGH PRETTY QUICKLY AND ONLY
IMPACT THE CWA IN THE AFTERNOON TO EVENING HOURS WITH A LIGHT
DUSTING OF SNOW. DUE TO THE UNCERTAINTY...WILL MAINTAIN ONLY THE
MENTION OF CHANCE POPS AT THIS TIME BUT LEAN TOWARDS A LATER POINT
IN THE DAY FOR IT TO MOVE THROUGH. CONDITIONS WILL REMAIN NEAR TO
BELOW NORMAL TO CLOSE OUT THE WEEKEND.
RIDGING WILL THEN BUILD IN ON SUNDAY NIGHT AND INTO THE OPENING OF
NEXT WEEK ALLOWING TEMPERATURES TO CREEP UP TO ABOVE FREEZING
BUT...THERE IS SOME QUESTION AS TO HOW WARM IT WILL GET WITH SNOW
REMAINING ON THE GROUND THROUGH THAT TIME. NEXT UPPER LEVEL TROUGH
WILL SWING THROUGH MONDAY NIGHT INTO TUESDAY...LIFTING A SURFACE
FEATURE NORTHEAST THROUGH MICHIGAN INTO THAT TIME. PROFILES
SUGGEST THAT WITH THE MODERATE WARM AIR ADVECTION GOING ON...THAT
PTYPE WILL START AS RAIN BEFORE QUICKLY BECOMING SNOW AS THE
ENTIRE PROFILE DIPS BELOW FREEZING. THE ROLLER COASTER OF TEMPS
RISING AND FALLING WITH WEAK UPPER LEVEL DISTURBANCES ZIPPING
THROUGH ARE EXPECTED TO CONTINUE INTO NEXT WEEKEND.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 04Z...
* LOWERING CEILINGS LATE TONIGHT/EARLY THURSDAY MORNING...WITH
MVFR CEILINGS BECOMING IFR ON THURSDAY.
* SNOW DEVELOPING BY MID TO LATE THURSDAY MORNING AND CONTINUING
THROUGH THE REMAINDER OF THE FORECAST PERIOD.
* LIKELY SEVERAL HOUR PERIOD OF IFR TO LIFR VIS THURSDAY AFTERNOON
INTO THE EVENING IN SNOW AND BLOWING SNOW.
KJB
//DISCUSSION...UPDATED 00Z...
THE FIRST APPRECIABLE WINTER WEATHER EVENT OF THE SEASON IS SET TO
IMPACT THE TERMINALS FOR MUCH OF THE DAY ON THURSDAY AND INTO
THURSDAY NIGHT. THIS IS A RATHER COMPLEX AND DYNAMICAL STORM
SYSTEM THAT LOOKS TO BRING A PERIOD OF MODERATE TO HEAVY SNOW TO
THE NORTHEASTERN ILLINOIS TERMINALS DURING THE AFTERNOON AND
EVENING HOURS ON THURSDAY. THIS WILL BE THE MAIN CONCERN AS SNOW
AND BLOWING SNOW WILL LIKELY LEAD TO A PERIOD OF IFR TO LIFR VIS
AND CIGS THURSDAY AFTERNOON AND INTO THE EVENING.
THE MAIN COLD FRONT IS NOW MOVING ACROSS EASTERN IOWA. THIS FRONT
SHOULD MOVE ACROSS NORTHEASTERN ILLINOIS AFTER 06 UTC TONIGHT.
BEHIND THIS FRONT...EXPECT WINDS TO BECOME GUSTY OUT OF THE
NORTHWEST LATER TONIGHT. THE MAIN SURFACE LOW WILL QUICKLY INTENSIFY
DURING THE MORNING ON THURSDAY ACROSS THE GREAT LAKES REGION. THIS
WILL SET THE STAGE FOR GUSTY NORTHWEST WINDS THROUGH THE REMAINDER
OF THE FORECAST PERIOD.
AS FAR AS SNOWFALL...IT APPEARS SNOWFALL WILL BEGIN DURING
THE MID TO LATE MORNING HOURS (AFTER 15 UTC AT THE NORTHEASTERN
ILLINOIS TERMINALS) AS STRONG FORCING FOR ASCENT COMMENCES IN
RESPONSE TO THE ATMOSPHERIC DYNAMICS OF THIS DEEPENING SURFACE LOW.
EXPECT THE ONSET TIME A FEW HOURS SOONER AT KRFD. THE SNOW SHOULD
PICK UP IN INTENSITY DURING THE AFTERNOON HOURS (AFTER 19 UTC) AS
THE DYNAMICS REACH A PEAK ALONG THE LEADING EDGE OF THE COLDEST AIR.
THIS COULD LEAD TO A PERIOD OF VISIBILITIES IN SNOW AND BLOWING SNOW
UNDER 1/2 MILE THROUGH THE AFTERNOON AND EARLY EVENING. THE SNOWFALL
SHOULD BEGIN TO ABATE LATER THURSDAY NIGHT INTO FRIDAY MORNING AS
THE STORM SYSTEM SHIFTS EAST ACROSS THE EASTERN GREAT LAKES.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 04Z...
* HIGH CONFIDENCE WITH CEILINGS AND TRENDS LATE TONIGHT/EARLY
THURSDAY.
* HIGH CONFIDENCE OF SNOW WITH MEDIUM CONFIDENCE OF TIMING AND VIS
TRENDS ON THURSDAY.
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...IFR CIGS/VIS EARLY IN SNOW AND BLOWING SNOW. CONDITIONS
IMPROVING THROUGH THE DAY.
SATURDAY...CHANCE OF SNOW WITH MVFR CIGS/VIS.
SUNDAY...VFR.
MONDAY AND TUESDAY...CHANCE OF SNOW SHOWERS WITH MVFR CIGS/VIS.
KJB
&&
.MARINE...
145 PM CST
LOW PRESSURE OVER THE TENNESSEE VALLEY THIS AFTERNOON WILL CURVE
NORTHEAST INTO THE EASTERN GREAT LAKES AND INTENSIFY LATE TONIGHT
AND THURSDAY AS AN ARCTIC AIR MASS PLUNGES SOUTH FROM CENTRAL
CANADA AND THE NORTHERN PLAINS. LIGHT SOUTHEAST WINDS THIS
AFTERNOON WILL BACK NORTHEAST...THEN NORTHWEST AND INCREASE LATE
TONIGHT AND THURSDAY MORNING. WINDS WILL CONTINUE TO RAMP UP
THURSDAY WITH GALE FORCE WINDS OVER THE OPEN WATERS BY LATE
AFTERNOON. WITH WINDS OFFSHORE...WILL LIKELY STAY BELOW GALES FOR
THE ILLINOIS NEARSHORE...BUT EXPECT GALE FORCE WINDS ALONG THE
INDIANA NEARSHORE WATERS. GALES WILL LIKELY CONTINUE THROUGH
FRIDAY AFTERNOON AS THE LOW SPINS OVER THE LOWER LAKES FOR A WHILE
BEFORE MOVING EAST. HIGH PRESSURE WILL BRING DIMINISHING WINDS
LATE FRIDAY NIGHT AND SATURDAY MORNING. WEAK LOW PRESSURE MOVING
THROUGH THE MIDWEST SATURDAY AFTERNOON AND EVENING WILL HAVE
LITTLE IMPACT ON THE LAKE. AS HIGH PRESSURE MOVES EAST ACROSS THE
LAKES SUNDAY WINDS WILL VEER SOUTH THEN INCREASE SUNDAY NIGHT AND
MONDAY.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-
ILZ019-ILZ021-ILZ032...6 AM THURSDAY TO 4 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-
ILZ020-ILZ022-ILZ023-ILZ033-ILZ039...9 AM THURSDAY TO 9 AM
FRIDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...9
AM THURSDAY TO 9 AM FRIDAY.
LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM
THURSDAY TO 3 PM FRIDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...NOON
THURSDAY TO MIDNIGHT SATURDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...NOON THURSDAY TO 3 PM
THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1121 PM CST WED JAN 11 2012
.AVIATION...
FOR THE 06Z TAF ISSUANCE...
GUSTY NORTH WINDS AT AROUND 20KTS WILL CONTINUE THROUGH AT LEAST
09Z AS A 700MB COLD POOL CROSSES SOUTHWEST KANSAS. THESE GUSTY
WINDS ARE EXPECTED TO BRIEFLY SUBSIDE SLIGHTLY TOWARDS DAYBREAK
BUT WILL THEN REBOUND BACK TO AROUND 25 KNOTS BY MID MORNING AS
MIXING IMPROVES. AFTER 00Z FRIDAY THE WINDS WILL BEGIN TO DECREASE
AS THE SUNSETS AND THE ATMOSPHERE DECOUPLES. OTHER THAN SOME MID
LEVEL MOISTURE ACCOMPANYING THE COLD POOL EARLY THIS MORNING THE
BUFR SOUNDINGS INDICATING VFR CONDITIONS THROUGH THURSDAY NIGHT.
-RB
&&
PREV DISCUSSION... /ISSUED 203 PM CST WED JAN 11 2012/
SYNOPSIS...
12Z RAOB PLOT ANALYSIS INDICATES A LARGE TROUGH PUSHING ACROSS THE ROCKIES
AND INTO THE NORTHERN PLAINS. THIS FEATURE HAS USHERED IN A COLD FRONT
EARLY THIS MORNING ACROSS SOUTHWEST KANSAS. AS OF 18Z, THIS FRONT IS
STILL MOVING ACROSS OKLAHOMA. WINDS WERE STRONG BEHIND THE FRONT WITH
MANY OBSERVATION SITES ACROSS WESTERN KANSAS REPORTING WINDS AROUND
30 KT.
DISCUSSION...
DAYS 1-2...
TONIGHT:
SHORT TERM FOCUS IS WINDS. HAVE UPDATED THE WIND ADVISORY FOR THE ENTIRE
REGION AS AWOS SITES ACROSS FAR WESTERN KANSAS HAVE BEEN AT WIND ADVISORY
CRITERIA EARLIER. HRRR AND NAM SHOW THAT WINDS WILL QUICKLY TAPER TOWARDS
6 PM CST. SECOND SHORT TERM FOCUS IS IF WE WILL SEE PRECIPITATION. THE
NAM HAS VERY LIGHT QPF ACROSS CENTRAL KANSAS TONIGHT. HRRR ALSO INDICATES
LIGHT COMPOSITE REFLECTIVITY FORECAST SO HAVE PUT 20 POPS ACROSS THE
NORTHEAST/NORTH. ELSEWHERE, WILL KEEP AROUND 10 PERCENT WITH FLURRIES. THIS
ACTIVITY WILL DIMINISH THIS EVENING. OVERNIGHT LOWS WILL BE ON THE COLD
SIDE AS WINDS WEAKEN AND SKIES CLEAR. WINDS WILL NOT COMPLETELY CALM
SO DID NOT GET TOO CARRIED AWAY WITH LOWS.
THURSDAY/THURSDAY NIGHT:
ANOTHER WINDY DAY LOOKS LIKELY ACROSS SOUTHWEST KANSAS TOMORROW. THIS
IS IN ASSOCIATION WITH A TIGHT PRESSURE GRADIENT REMAINING OVER THE
AREA. HAVE INCREASED WINDS IN THE GRIDS IN THE 20 TO 30 MPH RANGE BUT
KEPT VALUES/GUSTS BELOW WIND ADVISORY CRITERIA. INSTEAD OF HAVING TWO
WIND ADVISORIES OUT, WHICH COULD BE CONFUSING...I WILL LET THE MID SHIFT
DECIDE IF WE NEED A WIND ADVISORY OR NOT. TOMORROWS HIGHS WILL BE IN
THE 30S DEG F. OVERNIGHT LOWS ARE EXPECTED TO BE IN THE TEENS DEG F.
FRIDAY:
KANSAS WILL BE IN NORTHWEST FLOW ALOFT WHICH FAVORS A DRY FORECAST.
WILL KEEP POPS AT ZERO FRIDAY. COULD SEE SOME DOWNSLOPE WESTERLY WINDS
FRIDAY SO HAVE WARMED HIGHS UP A BIT. 850 HPA TEMPERATURES WARM UP INTO
THE LOWER SINGLE POSITIVE DIGITS DEG C, SO WE COULD SEE SOME MIXING
TO 40S DEG F AT THE SURFACE.
DAYS 3-7...
THE MID TO UPPER-LEVEL FLOW WILL GRADUALLY TRANSITION FROM
NORTHWESTERLY TO WEST-SOUTHWESTERLY FROM FRIDAY NIGHT INTO SUNDAY.
THUS, SURFACE PRESSURES WILL FALL IN THE LEE OF THE ROCKIES ALONG
WITH SOME WEAK LOW-LEVEL DOWNSLOPE FLOW. HIGH TEMPERATURES WILL
MODIFY INTO THE MID 50S BY SATURDAY AND 55 TO 60 BY SUNDAY.
A SHORTWAVE TROUGH WILL PROGRESS IN MAINLY ZONAL FLOW ACROSS THE
CENTRAL AND NORTHERN PLAINS BY MONDAY AND MONDAY NIGHT. THIS WILL
BRING SOME COLDER AIR INTO WESTERN KANSAS. SO AFTER A FAIRLY MILD
DAY MONDAY (50S TO LOWER 60S) JUST IN ADVANCE OF THE FRONT, HIGHS
WILL FALL INTO THE 30S OR LOWER 40S BY TUESDAY. NO PRECIPITATION CAN
BE EXPECTED IN THIS ZONAL PATTERN.
ANOTHER WARMING TREND IS EXPECTED BY JANUARY 18-19TH WITH HIGHS
POSSIBLY REACHING TO NEAR 70F IN A GENERALLY ZONAL MID TO UPPER-LEVEL
FLOW REGIME WITH LEE-TROUGHING AT LOW-LEVELS. HOWEVER, AS IS OFTEN
THE CASE IN ZONAL REGIMES, THERE WILL BE A SHARP TEMPERATURE
GRADIENT BETWEEN DOWNSLOPE FLOW OVER THE SOUTHERN AND CENTRAL PLAINS
AND ARCTIC AIR OVER THE NORTHERN PLAINS OR SOUTHERN CANADA. ANY
SHORTWAVE TROUGH TRAVERSING THE FLOW COULD RESULT IN ANOTHER SURGE
OF COLD AIR. THE ECMWF IS ADVERTISING ANOTHER SUCH COOLDOWN BY
JANUARY 20-21ST. NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH
JANUARY 21ST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 12 35 14 46 / 10 0 0 0
GCK 11 35 12 47 / 10 0 0 0
EHA 11 37 15 48 / 10 0 0 0
LBL 11 36 15 48 / 10 0 0 0
HYS 11 33 11 46 / 10 0 0 0
P28 17 37 15 46 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
102 AM EST THU JAN 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OVERNIGHT. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST THURSDAY AND TRACK THROUGH THE GULF OF MAINE
THURSDAY NIGHT. ANOTHER LOW WILL MOVE NORTH THROUGH NEW ENGLAND
FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE 0100L...
FIRST ISSUE WAS TO RAISE OVERNIGHT INTO EARLY MORNING TEMPS DUE TO
THICKENING CLOUD COVER. ALSO BROUGHT LOWER CLOUDS INTO DOWN EAST
EARLY THIS MORNING AS COASTAL FRONT ORGANIZES WITH SIGNIFICANT
TEMPERATURE GRADIENT ALONG COAST. WITH SOME COLD AIR DAMMING
SETTING UP...LOOKED AT NORMALLY COLD RUC OUTPUT AND IT IS BRINGING
IN WARM AIR RIGHT ALONG THE COAST AND A WARM LAYER ALOFT NEAR H850
EARLIER THAN OTHER MODELS. THIS MEANS LESS SNOW ACCUMULATION ALONG
THE COAST AND NORTHWARD TO BGR DUE TO MIXED PRECIP. NEW
EXPECTATION IS JUST OVER 4 INCHES AROUND BGR AND DROPPING OFF TO
THE ONE TO THREE INCH RANGE IN THE ZONES 29 AND 30 WITH THE LOWEST
VALUES ALONG THE COAST AND OUTER ISLANDS. THE BEST SNOW
ACCUMULATIONS SHOULD BE ALONG THE HIGHER TERRAIN FROM JUST SOUTH
OF GREENVILLE TOWARDS PATTEN AND SHIN POND WHERE COLDER AIR ALOFT
AND UPSLOPE SHOULD MAXIMIZE SNOWFALL.
UPDATE...
HIGH PRESSURE WILL MOVE EAST OVERNIGHT WHILE LOW PRESSURE DEVELOPS
ALONG THE MID ATLANTIC COAST. SKIES WILL BE CLOUDY ACROSS THE
FORECAST AREA OVERNIGHT. LOW TEMPERATURES TONIGHT WILL GENERALLY
RANGE FROM AROUND ZERO NORTH...TO 10 TO 15 DOWNEAST. HAVE UPDATED
THE FORECAST TO ADJUST FOR CURRENT CONDITIONS ALONG WITH EXPECTED
OVERNIGHT CLOUDS/TEMPERATURES.
PREVIOUS DISCUSSION...
THE LOW PRESSURE CENTER WITH THE SYSTEM THURSDAY WILL TRACK
NORTHEAST RIGHT ALONG THE COAST IN THE AFTERNOON AND THURSDAY
NIGHT. NEARLY ALL THE PRECIPITATION AND STRONGER WINDS WILL BE ON
THE LEADING EDGE OF THE SURFACE LOW...AS THE UPPER LEVEL TROUGH
AND DYNAMICS ARE EASILY OUTPACING THE SURFACE LOW.
LOOK FOR SNOW TO BEGIN AROUND MIDDAY OVER SOUTHERN
MAINE...SPREADING NORTH TO THE ENTIRE AREA BY LATE AFTERNOON OR
EVENING. THE BEST DYNAMICS SUCH AS THE STRONGEST LIFT AND WARM
ADVECTION WILL BE OVER SOUTHEAST HALF OF THE AREA WITH THE HIGHEST
PRECIPITATION AMOUNTS THERE. HOWEVER...TEMPERATURES WILL BE ON THE
RISE THROUGH THE EVENT WITH LOWERING SNOW RATIOS AND MIXED
PRECIPITATION TOWARD THURSDAY EVENING PROBABLY KEEPING SNOW TOTALS
AT FOUR TO SIX INCHES...JUST BELOW WARNING CRITERIA.
FURTHER NORTH...EXPECT THE PRECIPITATION TYPE TO BE ALL SNOW
NORTHWEST OF HOULTON FOR THIS FIRST ROUND LATE THURSDAY/THURSDAY
NIGHT. THE PRECIPITATION WILL NOT BE AS HEAVY UP NORTH...SO EXPECT
ABOUT THREE OR FOUR INCHES OF SNOW FOR THE SAINT JOHN VALLEY SOUTH
TO CARIBOU AND PRESQUE ISLE. AGAIN...THIS IS JUST REFERRING TO THE
FIRST ROUND THURSDAY/THURSDAY NIGHT.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
INTENSE LOW PRESSURE MOVES INTO THE GREAT LAKES THURSDAY EVENING
WHILE SECONDARY LOW CENTER DEVELOPS IN THE GULF OF MAINE. THE
SECONDARY LOW WILL MOVE THROUGH THE GULF OF MAINE THURSDAY NIGHT
THEN INTO NEW BRUNSWICK FRIDAY MORNING. THE PRIMARY LOW WILL MOVE
FROM GREAT LAKES NORTHEASTWARD ACROSS FAR NORTHERN MAINE FRIDAY.
EXPECT HEAVIES SNOW FROM PRIMARY LOW TO STAY NORTHWEST OF THE
FORECAST AREA FRIDAY WHILE RESULTING IN MIXED PRECIPITATION OVER
THE REMAINDER OF THE REGION. GFS...NAM12 AND ECMWF INDICATE
HIGHEST AMOUNTS SOUTH. WITH COLD AIR DAMMING INLAND...SEA SURFACE
TEMPERATURE IN MID 40S AND SOME INSTABILITY ALOFT EXPECT COASTAL
FRONT TO BE FACTOR IN ENHANCING QPF AMOUNT SOUTH. FOR POPS HAVE
BLENDED THE NAM12...GFS40 AND SREF THEN MANUALLY ADJUSTED.
TEMPERATURE GRIDS RUN ON NAM12 INTO FRIDAY EVENING THEN TRANSITION
TO GMOS. PRECIPITATION TYPE GENERATED WITH THICKNESS TOOL RUN ON
50/50 BLEND OF THE NAM AND GFS. SNOW AMOUNT GENERATED WITH
OFFICE SNOW FROM THICKNESS RUN ON NAM12.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE EXTENDED MODELS ARE IN GOOD GENERAL AGREEMENT THROUGH THE
PERIOD. HIGH PRESSURE WILL DOMINATE THE WEATHER FOR THE AREA
THROUGH EARLY TUESDAY AFTERNOON. A LOW PRESSURE SYSTEM THAT STARTS
IN THE SOUTHERN PLAINS ON MONDAY WILL TRACK NORTHEAST INTO THE
GREAT LAKES REGION BY EARLY TUESDAY MORNING. THIS LOW WILL MOVE
INTO SOUTHERN QUEBEC BY TUESDAY AFTERNOON WITH ITS COLD FRONT
EXTENDED SOUTH ALONG THE BOARDER WITH MAINE. BY EARLY WEDNESDAY
MORNING THE COLD FRONT WILL PUSH THROUGH THE AREA AND HIGHER
PRESSURE WILL BUILD INTO THE REGION THROUGH THE END OF THE PERIOD.
LOADED GMOS. ADJUSTED SKY AND POP GRIDS TO BETTER SUPPORT ONE
ANOTHER. LOADED NAWAVE 4 FOR SEAS. PLUS 15 PERCENT FOR WINDS GUST
OVER LAND 20 PERCENT OVER WATER.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION OVERNIGHT.
CONDITIONS WILL LOWER TO MVFR/IFR LEVELS...FROM SOUTH TO NORTH
ACROSS THE REGION...THURSDAY WITH PRECIPITATION EXPANDING NORTH.
SHORT TERM: EXPECT IFR/MVFR CONDITIONS THROUGH FRIDAY NIGHT THEN
VFR CONDITIONS SATURDAY THROUGH MONDAY.
&&
.MARINE...
NEAR TERM: CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY
LEVELS OVERNIGHT. WINDS WILL THEN RAPIDLY INCREASE TO GALE LEVELS
THURSDAY...WITH A GALE WARNING IN EFFECT STARTING THURSDAY
AFTERNOON. VISIBILITIES WILL LOWER IN DEVELOPING SNOW AND RAIN
THURSDAY.
SHORT TERM: HAVE USED THE NAM12 FOR WIND GRIDS. FOR WAVES HAVE
USED THE SWAN/NAM UNTIL 0000Z SATURDAY THEN TRANSITION TO THE WNA/4.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 7 PM EST
FRIDAY FOR MEZ001-002.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM EST
FRIDAY FOR MEZ003>006-011.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 1 PM EST FRIDAY FOR
MEZ016-017-029-030.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 PM EST FRIDAY FOR
MEZ010-015-031.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 1 PM EST
FRIDAY FOR MEZ032.
MARINE...GALE WARNING FROM NOON TODAY TO 10 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...FOISY/MCW
SHORT TERM...MIGNONE
LONG TERM...NORTON
AVIATION...FOISY/MCW
MARINE...FOISY/MCW/MIGNONE
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1106 PM EST WED JAN 11 2012
.SYNOPSIS...
LOW PRESSURE WILL BRING RAIN SHOWERS INTO THURSDAY. HIGHER MOUNTAINS
MAY UNDERGO A PERIOD OF FREEZING RAIN AND DENSE FOG OVERNIGHT. A
STRONG COLD FRONT WILL CAUSE A FAST TEMPERATURE DROP AND CHANGE TO
SNOW SHOWERS AND SLIPPERY CONDITIONS LATE THURSDAY NIGHT, AND BE
ACCOMPANIED BY GUSTY WIND THAT WILL CONTINUE INTO FRIDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH RECENT HRRR AND
WRF-NMM MODEL OUTPUT, EXPECT PATCHES OF FREEZING RAIN AND DENSE
FOG OVERNIGHT. HAVE ISSUED A FREEZING RAIN ADVISORY TIL 6 AM FOR
TUCKER COUNTY WV AND GARRETT COUNTY MD.
AS LOW PRESSURE CENTER GETS CLOSER, SHOWERS HAVE DECREASED IN
COVERAGE WEST OF THE MOUNTAINS. WIND HAVE BEGUN GUSTING OVER 30
MPH DOWNWIND OF THE SOUTHERN MOUNTAINS, WHICH WILL HAVE TO BE
MONITORED.
RECENT MODEL OUTPUT SUGGEST THERE CAN BE A SECOND SURGE OF SHOWERS
LATE TONIGHT INTO FRIDAY MORNING, MAINLY NEAR THE MOUNTAINS.
TEMPERATURES WILL BE NEARLY STEADY IN SOUTHERLY FLOW ON FRONT
SIDE OF SYSTEM. LOW PRESSURE EXITS DURING THE DAY THURSDAY WITH
SHOWERS DIMINISHING DURING THE MORNING. TEMPERATURES WILL STAY
ABOVE NORMAL THURSDAY AHEAD OF APPROACHING COLD FRONT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
BLEND OF RECENT SREF MODEL OUTPUT SHOWS STRONG COLD FRONT WILL
MOVE EASTWARD THROUGH THE UPPER OHIO VALLEY THURSDAY NIGHT. THIS
WILL CAUSE A FAST TEMPERATURE DROP AND SUBSEQUENT FAST CHANGE OF
RAIN SHOWERS TO SNOW SHOWERS TOWARD MIDNIGHT. THE FAST CHANGE CAN
RESULT IN ICY CONDITIONS QUICKLY DEVELOPING WHICH HAS BEEN
MENTIONED IN THE HAZARDOUS WEATHER OUTLOOK.
WITH COLD FLOW BEING MAINLY FROM THE WEST AND SOUTHWEST, EXPECT
SNOW ACCUMULATION AMOUNT TO BE IN SUBADVISORY RANGE LATE THURSDAY NIGHT
INTO DAYTIME FRIDAY. HOWEVER, IMPACT OF ICING CONDITIONS MAY ALSO
BE A PLAYER IN HEADLINE DECISIONS.
NAM MODEL PROFILES SHOW POST FRONTAL WIND GUSTS CAN REACH THE 30
TO 40 MPH RANGE LATE THURSDAY NIGHT AND FRIDAY.
AS SYSTEM MOVES TO NEW ENGLAND SATURDAY, SCATTERED SNOW SHOWERS
WILL CONTINUE WITH WINDS ONLY SLOWLY DIMINISHING.
FORECASTED TEMPERATURES CLOSE TO BLEND OF GFS AND NAM MOS WHICH
LOOK TO HAVE A GOOD HANDLE ON COLD AIR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ANOTHER SHORTWAVE TROUGH AND ASSOCIATED SURFACE WEAK LOW IS PROGGED
TO CROSS THE OHIO VALLEY SATURDAY NIGHT AND EARLY SUNDAY BRINGING
SCATTERED SNOW SHOWERS. RIDGING AT THE SURFACE AND ALOFT SHOULD
PROVIDE DRY WEATHER LATER SUNDAY INTO MONDAY.
THE NEXT UPPER TROUGH WILL SWING A COLD FRONT ACROSS THE GREAT
LAKES REGION TUESDAY...ALONG WITH SCATTERED RAIN AND SNOW
SHOWERS. PRECIPITATION IS FORECAST TO TAPER OFF WEDNESDAY WITH
JUST A FEW LINGERING SHOWERS NORTH AND ALONG THE RIDGES.
NEAR NORMAL TEMPERATURES SHOULD MODERATE TO BETWEEN 5 AND 10 DEGREES
ABOVE NORMAL BY TUESDAY...AND RETURN TO NEAR NORMAL BY MIDWEEK.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
WIDESPREAD RAIN ACROSS WESTERN PENNSYLVANIA TAPERS OFF ACROSS
EASTERN OHIO AND NORTHERN WEST VIRGINIA. CONDITIONS RANGE FROM IFR
AT FKL AND DUJ TO VFR SOUTH OF PITTSBURGH. AS RAIN SHIELD CONTINUES
TO MOVE TO THE NORTH...EXPECT THAT ALL SITES WILL RISE TO VFR FOR AT
LEAST A FEW HOURS. WITH SO MUCH MOISTURE AROUND...EXPECT THAT
CEILINGS WILL DROP BACK TO IFR AT ALL TERMINALS. WINDS AROUND 10 KT
SHOULD DECREASE SLIGHTLY OVERNIGHT. HOWEVER...LOW LEVEL WIND SHEAR
IS EXPECTED TO DEVELOP FOR A FEW HOURS AT ALL SITES EXCEPT ZZV. LLWS
WILL NOT PERSIST FOR TOO LONG...DIMINISHING BY MIDNIGHT.
WHILE A CHANCE OF SHOWERS REMAINS IN THE FORECAST ON
THURSDAY...COVERAGE IS NOT HIGH ENOUGH TO WARRANT MENTION IN TAFS AT
THIS TIME. IFR CONDITIONS MAY RISE TO MVFR BY THE AFTERNOON. GUSTY
WINDS WILL DEVELOP...WITH 20 KTS EXPECTED ON THURSDAY AFTERNOON AND
DIMINISHING AT SUNSET.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
COLDER AIR WILL PUSH INTO THE REGION THURSDAY NIGHT AND CHANGE
PRECIPITATION OVER TO SNOW SHOWERS. SURFACE WIND GUSTS OVER 30KT ARE
POSSIBLE THURSDAY NIGHT AND FRIDAY. MVFR AND AREAS OF IFR
RESTRICTIONS WILL CONTINUE THROUGH SATURDAY MORNING.
SCATTERED SNOW SHOWERS SHOULD TAPER OFF DURING THE DAY SATURDAY.
ANOTHER LOW PRESSURE SYSTEM WILL SWING ACROSS THE OH VALLEY
SUNDAY...BRINGING THE POTENTIAL FOR RESTRICTIONS. A SURFACE RIDGE IS
PROGGED TO BUILD IN SUNDAY NIGHT AND MONDAY...WITH CONDITIONS
EXPECTED TO IMPROVE TO VFR.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZING RAIN ADVISORY UNTIL 6 AM EST THURSDAY FOR MDZ001.
OH...NONE.
PA...NONE.
WV...FREEZING RAIN ADVISORY UNTIL 6 AM EST THURSDAY FOR WVZ041.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
103 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX STORM SYSTEM APPROACHING FROM THE TENNESSEE VALLEY WILL
SEND RAIN...AND A WINTRY MIX FOR THE EASTERN LAKE ONTARIO
REGION...ACROSS THE EASTERN GREAT LAKES OVERNIGHT AND INTO THURSDAY
MORNING. A BRIEF LULL IN THE PRECIPITATION ACROSS MUCH OF THE REGION
LATER TOMORROW AS THE RAIN AND WINTERY MIX PUSHES NORTHWARD BEFORE
ADDITIONAL RAIN CHANGING TO SNOW SWEEPS IN FROM THE WEST OVERNIGHT.
WINDS WILL BECOME BLUSTERY FRIDAY WITH WIDESPREAD
SNOWFALL...BECOMING MORE CONCENTRATED DOWNWIND OF BOTH OF THE
LAKES...WITH THE POTENTIAL FOR THIS LAKE EFFECT SNOW TO CONTINUE
INTO SATURDAY BEFORE DIMINISHING.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 06Z...RAIN HAS LIFTED ACROSS ALL OF WESTERN NEW YORK AND
IS JUST NOW STARTING EAST OF LAKE ONTARIO AS A WINTRY MIX. WHILE
TEMPERATURES ARE SAFELY ABOVE FREEZING ACROSS THE WESTERN COUNTIES...
THE SAME CANNOT BE SAID FROM THE TUG HILL NORTH AND EAST.
A WAVY FRONTAL BOUNDARY STRETCHED ACROSS THE NORTH COUNTRY AS OF 06Z
WITH COLD AIR DAMMING EVIDENT ON A SFC ANALYSES FROM WATERTOWN
ACROSS THE THOUSAND ISLANDS TO THE ST LAWRENCE VALLEY. TEMPERATURES
NORTH OF THE BOUNDARY ARE IN THE TEENS AND 20S...AND WITH A
NORTHEAST LOW LEVEL FLOW HOLDING IN PLACE THROUGH THE NIGHT AND
LIKELY THROUGH A LARGE PART OF THURSDAY...A PROLONGED MIXED BAG OF
FREEZING RAIN...SLEET AND EVEN A BIT OF WET SNOW WILL FALL.
LIKE THE PREVIOUS SHIFT...AM CONCERNED ABOUT WHETHER ENOUGH ICE
COULD ACCUMULATE TO WARRANT A WARNING VERSUS THE CURRENT WINTER
WEATHER ADVISORY. QPF AMOUNTS WILL AVERAGE ABOUT A HALF INCH THROUGH
MIDDAY THURSDAY...BUT ENOUGH OF THE PCPN SHOULD FALL AS SLEET TO
KEEP FREEZING RAIN AMOUNTS BELOW WARNING CRITERIA. WILL HOLD ONTO
THE ADVISORY FOR JEFFERSON AND LEWIS COUNTIES FOR NOW...ALTHOUGH IT
MAY NEED TO BE EXTENDED DEEPER TO THURSDAY EVENING. AT THIS POINT...
AM LEANING TOWARDS DROPPING THE ADVISORY WITH THE UPCOMING EARLY
MONRING PACKAGE FOR OSWEGO COUNTY WHERE COLD AIR DAMMING IS NOT AN
ISSUE.
THE RAIN ACROSS THE REGION TYHROUGH DAYBREAK WILL BE THE RESULT OF
BEING UNDER THE RR ENTRANCE REGION OF A 120 KT JET OVER QUEBEC AND
CONVERGENCE FOUND ALONG A 50KT 900 HPA JET. DEEPEN MOISTURE IN THE
LOWER LEVELS...WITH PWATS RISING TO NEAR +2SD OVERNIGHT WILL FUEL
THE PRECIPITATION THROUGH THE OVERNIGHT. EXPECT BASIN QPF AVERAGES
TO BE AROUND 0.40 TO 0.75 INCHES OVERNIGHT WITH THE HIGHEST TOTALS
TOWARDS THE EAST...CLOSER TO THE CORE OF THE LLJ.
ON THURSDAY...AN OCCLUDED FRONT FROM THE PRIMARY LOW OVER OHIO WILL
PUSH NORTHWARD TOWARDS THE SOUTHERN SHORELINE OF LAKE ONTARIO BY
AFTERNOON. DRIER AIR IN THE MID LEVELS (700MB AS PER THE GFS) WILL
LIFT ACROSS THE REGION DURING THE DAY THURSDAY...SHUTTING DOWN THE
STEADY RAIN AND MAKING THE PCPN MORE SPOTTY IN NATURE...WITH LIGHT
RAIN SHOWERS OR DRIZZLE BEING EXPERIENCED. THE EXCEPTION WILL COME
ALONG THE LAKE ONTARIO SHORELINE AND ACROSS THE NORTH COUNTRY WHERE
THIS REGION WILL REMAIN NORTH OF THE SFC BOUNDARY.
TEMPERATURES FOR THE REST OF THE OVERNIGHT...TEMPERATURES WILL
REMAIN ABOVE FREEZING ACROSS THE WESTERN COUNTIES WHILE SUB FREEZING
CONDITIONS WILL BE FOUND NORTH AND EST OF THE TUG. FOR THURSDAY...
MERCURY READINGS WILL GENERALLY BE IN THE 40S WITH THE COLDER AIR
NORTH OF THE TUG FINALLY BEING MODIFIED TOWARDS EVENING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
A VERY COMPLEX WEATHER SCENARIO WILL BE UNFOLDING DURING THIS PERIOD
AS THE SOUTHERN STREAM LOW LIFTING INTO THE NORTHEAST CONUS IS
INTERCEPTED BY A DEEP UPPER LEVEL TROUGH DROPPING ACROSS THE
NORTHERN PLAINS INTO THE GREAT LAKES WITH THE RESULT BEING A DOUBLE
SURFACE LOW STRUCTURE ACROSS THE REGION. THE DOMINANT LOW WILL BE
ACROSS THE GREAT LAKES...WHILE THE SECONDARY WEAKER LOW RESIDES OFF
THE SOUTHERN NEW ENGLAND COAST AT THE START OF THE PERIOD. THE MAIN
OCCLUSION WILL BE NORTH OF THE AREA WHICH SHOULD HAVE WESTERN AND
CENTRAL NEW YORK IN A RELATIVE LULL IN PRECIPITATION AT THE BEGIN OF
THURSDAY NIGHT. LATER THURSDAY NIGHT THERE WILL BE RAPID CYCLONE
INTENSIFICATION BOTH AT THE SURFACE AND ALOFT WHICH WILL CORRESPOND
WITH INCREASE LAKE ENHANCEMENT OFF LAKE ERIE AND INCREASING ATLANTIC
MOISTURE INFLOW...WHICH SHOULD POINT TO THE EXPANSION OF SNOW OR
MIXED PRECIPITATION ACROSS EASTERN SECTION ALONG THE INTENSIFYING
BAROCLINIC ZONE UNDERNEATH THE DEEPENING COUPLED JET CIRCULATION
ALOFT. THE DEEPENING SURFACE LOW WILL BE LIFTING THROUGH SAINT
LAWRENCE VALLEY FRIDAY...WITH THE SUGGESTION OF A TROWAL FEATURE
DEVELOPING IN ASSOCIATION WITH THE MID LEVEL DEFORMATION ZONE.
ORIENTATION OF THIS FEATURE DIFFERS FROM MODEL TO MODEL MAKING THE
PLACEMENT OF POTENTIAL HEAVY SNOWFALL AXIS FRIDAY RATHER DIFFICULT.
STILL PLENTY OF UNCERTAINTY TO HOW THE SYNOPTIC PORTION OF THIS
SYSTEM WILL PLAY OUT PLACING RELATIVE LOW CONFIDENCE IN SNOWFALL
FORECAST FOR THE THURSDAY NIGHT AND FRIDAY TIME FRAME. WE ARE LIKELY
LOOKING AT A GENERAL ACCUMULATING SNOW SEVERAL INCHES...ALTHOUGH
SIGNIFICANT AMOUNTS TO THE LEE OF THE LAKES WILL BE POSSIBLE...
ESPECIALLY IF LAKE ENHANCEMENT CAN GET GOING EARLY ENOUGH.
STARTING LATE FRIDAY...THE LAKE EFFECT SNOW WILL BEGIN IN EARNEST AS
THE FLOW VEERS TO WEST...THEN TO WEST NORTHWEST AND 850 MB
TEMPERATURES DROP INTO THE NEGATIVE LOWER TEENS CELSIUS. PLENTY OF
SYNOPTIC SCALE MOISTURE WILL BE IN PLACE ALLOWING IMPRESSIVE DEPTH
OF FAVORABLE DENDRITIC SNOW GROWTH REGION TO INTERSECT OMEGA
MAXIMUM. THIS WOULD SUGGEST THE POTENTIAL FOR HEAVY LAKE SNOWS IN
THE TRADITIONAL WEST NORTHWEST FLOW REGIONS SOUTH OF BUFFALO AND
WATERTOWN. STRONG WIND FIELDS MAY HAMPER THE ORGANIZED OF PROLONGED
LAKE BANDS...BUT THIS CAN BE ADDRESSED IN LATER FORECAST ISSUANCES.
LAKE EFFECT SETUP STILL FAR ENOUGH IN ADVANCE TO KEEP HEADLINES OUT
OF FORECAST FOR NOW.
WINDS MAY BECOME AN ISSUE FRIDAY...ESPECIALLY DOWNWIND OF THE LAKES
WITH BUFKIT MOMENTUM TRANSFER SCHEMES SUGGESTING A PERIOD OF SUSTAIN
WINDS OVER 25 KNOTS AND GUSTS OVER 40 KNOTS WHICH MAY PROMPT
HEADLINES IN LATER FORECASTS AS WELL.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BY THE END OF THE WEEKEND...AIR MASS STILL LOOKS PLENTY COLD ENOUGH
WITH 850 MB TEMPERATURES IN THE NEGATIVE MID TEENS CELSIUS TO
MAINTAIN THE POTENTIAL FOR LINGERING LAKE SNOWS SOUTHEAST OF THE
LAKES. SOME SUGGESTION THAT INVERSION HEIGHTS WILL BE LOWERING...
THEREFORE THE INTENSITY OF THE LAKE SNOWS IS IN QUESTION AT THIS
POINT. LAKE ACTIVITY WILL SHUT DOWN COMPLETELY SUNDAY NIGHT AND
MONDAY AS BROAD RIDGE PUSHES ACROSS THE REGION. THE RIDGE LOOKS TO
SLIDE EAST MONDAY NIGHT AND A STRONG WARM AIR ADVECTION PATTERN SETS
UP BEHIND IT AND AHEAD OF AN APPROACHING ELONGATED COLD FRONT.
INCREASE LOW LEVEL MOISTURE INFLOW AHEAD OF THIS FRONT WILL INCREASE
THE THREAT FOR SNOW IN THE MONDAY NIGHT AND TUESDAY TIME FRAME...
WITH THE ADDED LAKE COMPONENT AS COLDER AIR SPILLS BACK ACROSS THE
LOWER LAKES. AIR MASS LOOKS COLD ENOUGH WITH ENOUGH SYNOPTIC SCALE
MOISTURE TO REGENERATE WEST NORTHWEST FLOW LAKE SNOWS FOR TUESDAY
NIGHT AND WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
RAIN WILL BE FOUND ACROSS ALL OF WESTERN NEW YORK THROUGH THE
OVERNIGHT WITH CIGS DETERIORATING TO IFR LEVELS. FOR THE EASTERN
LAKE ONTARIO REGION...LOW LEVEL COLD AIR BEING FED SOUTH FROM THE ST
LAWRENCE VALLEY WILL RESULT IN A MIXED BAG OF WINTRY PCPN INCLUDING
SOME ICE FOR KART. SIGNIFICNAT ICING WILL BE POSSIBLE FOR THIS SITE
AND COULD SERIOUSLY AFFECT COMMERCIAL AIR TRAFFIC AND LOCAL
OPERATIONS.
IFR CIGS SHOULD BE IN PLACE FOR THE WESTERN NY TAF SITES BY THURSDAY
DAYBREAK WHILE MVFR CIGS WILL MOVE ACROSS KART. THESE CIGS WILL BE
WIDESPREAD THROUGH EARLY THURSDAY AFTERNOON BEFORE LOWER ELEVATIONS
POSSIBLY IMPROVE TO MVFR LATER IN THE DAY. HIGHER TERRAIN SHOULD
STAY LOCKED INTO IFR THROUGH THE AFTERNOON WITH STRATUS NEAR THE
HILLTOPS IN SOME LOCATIONS.
OUTLOOK...
THURSDAY NIGHT THROUGH FRIDAY...MVFR TO IFR WITH RAIN CHANGING TO
SNOW.
FRIDAY NIGHT AND SATURDAY MVFR IN CHC SNOW...HEAVIER SNOW LIKELY
SOUTHEAST OF THE LAKES WITH IFR CONDITIONS.
SUNDAY...MVFR TO VFR IN LINGERING SNOW SHOWERS.
MONDAY...MAINLY VFR.
&&
.MARINE...
AS EASTERLY WINDS INCREASE IN SPEED OVERNIGHT WINDS AND WAVES WILL
RISE ABOVE SCA CRITERIA...AND WILL ISSUE A SMALL CRAFT FOR THE
WESTERN HALF OF LAKE ONTARIO FOR LATE THIS EVENING THROUGH
THURSDAY.
MUCH COLDER AIR WILL SURGE ACROSS THE RELATIVELY WARM LAKE WATERS
THURSDAY NIGHT AND FRIDAY. THIS WILL PROMOTE STRONG MIXING WITHIN THE
LOWER LEVELS OF THE ATMOSPHERE...RESULTING IN A CHANCE FOR GALE
FORCE WINDS THURSDAY NIGHT AND FRIDAY. WILL ISSUE A GALE WATCH FOR
LAKE ERIE STARTING LATE THURSDAY NIGHT THROUGH FRIDAY. WINDS ON LAKE
ONTARIO WILL INCREASE LATER IN THE DAY FRIDAY...WITH WINDS NEARING
GALE FORCE LATE FRIDAY AFTERNOON.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ006>008.
MARINE...GALE WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON
FOR LOZ042-043.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...HITCHCOCK/THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...HITCHCOCK/RSH
MARINE...THOMAS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1235 AM EST THU JAN 12 2012
.SYNOPSIS...
A STORM SYSTEM WILL BRING PRECIPITATION TONIGHT INTO THURSDAY.
EAST OF INTERSTATE 81...ESPECIALLY AT HIGHER ELEVATIONS...THE
PRECIPITATION MAY BEGIN AS A WINTRY MIX OF FREEZING
RAIN...SLEET...AND SNOW. THE REMAINDER OF THE REGION WILL
GENERALLY HAVE JUST A COLD RAIN. HOWEVER...A COLD FRONT WILL SWEEP
THROUGH LATE THURSDAY NIGHT INTO FRIDAY MORNING...RESULTING IN
SNOW SHOWERS DURING THE DAY FRIDAY. COURTESY OF LAKE EFFECT...SNOW
SHOWERS CONTINUE INTO SATURDAY FOR MUCH OF THE REGION.
&&
.NEAR TERM /THROUGH TODAY/...
1030 PM UPDATE...NO CHANGES TO THE PREVIOUS FORECAST. UPDATE
EARLIER TO REMOVE SNOWFALL AMOUNTS LOOKS TO BE ON TRACK WITH JUST
A FEW REPORTS OF A FEW FLAKES AT THE ONSET. WE ARE MOSTLY SEEING SLEET
OR RAIN...WITH SOME POCKETS OF FREEZING RAIN. AS THE
PRECIPITATION MOVES FARTHER NORTH AND EAST AND ENCOUNTERS SOME
COLDER SURFACE TEMPS AND LOWER DEWPOINTS...FREEZING RAIN WILL
BECOME MORE LIKELY AND THE ADVISORY CURRENTLY IN PLACE COVERS
THIS. I WAS TEMPTED TO DROP MADISON...CHENANGO...PIKE...AND WAYNE
COUNTIES FROM THE ADVISORY WITH MOST MESONET SITES SHOWING TEMPS
IN THE MID 30S. DECIDED TO HOLD OFF BECAUSE WE HAVE GOTTEN A FEW
REPORTS OF FREEZING RAIN BUT THEY HAVE BEEN CONFINED TO ELEVATIONS
CLOSER TO 2000 FEET IN THESE AREAS. WITH THE UPDATE TO THE
ADVISORY...TRIED TO STRESS HIGHER ELEVATIONS HERE FOR THE FREEZING
RAIN POTENTIAL.
FARTHER NORTH AND EAST IN OUR NORMALLY COLDER SPOTS OF
ONEIDA...OTSEGO...DELAWARE AND SULLIVAN COUNTIES...FREEZING RAIN
POTENTIAL IS MUCH HIGHER AND I REMOVED ANY HIGHER ELEVATION
WORDING BECAUSE IT WILL BE MORE WIDESPREAD HERE AND NOT JUST
CONFINED TO THE HIGHEST TERRAIN. A GOOD EXAMPLE IS MONTICELLO
WHICH HAS DROPPED FROM 36 TO 32 AND IS PROBABLY SEEING SOME
FREEZING RAIN ATTM. THE PREVIOUS AFD IS BELOW...
730 PM
UPDATE...OVERALL FORECAST EVOLUTION IS IN GOOD SHAPE.
PRECIPITATION IS ADVANCING ACROSS THE SOUTHERN THIRD OF THE CWA AS
WE SPEAK. PREFER THE NAM/RUC FORECAST SOUNDINGS WHICH SHOW THE
PRECIPITATION STARTING OFF MOSTLY AS ALL RAIN IN THE LOWER
ELEVATIONS...WITH A MIX OF ANYTHING FROM RAIN TO SLEET OR EVEN A
FEW SNOWFLAKES ABOVE 1200 FEET. TAMDAR SOUNDINGS OUT OF SYRACUSE
SHOW THIS NICELY WITH PLENTY OF DRY AIR IN THE MID LEVELS ALLOWING
FOR SOME QUICK WET BULBING...BEFORE OUR WARM NOSE PUNCHES IN
AROUND 850 MB. THIS PUNCH OF WARMER AIR WILL TRANSITION MOST OF
THE AREA TO PLAIN RAIN. THE EXCEPTION WILL BE FARTHER EAST AND
NORTH...WHERE WE HAD ADVISORIES IN PLACE...WHERE THE MIX OF
SLEET/SNOW...AND EVEN SOME FREEZING RAIN WILL LINGER MUCH LONGER.
MAIN ADJUSTMENT TO THIS PACKAGE IS TO LOWER SNOWFALL AMOUNTS.
WHILE SOME SNOW IS POSSIBLE NEAR THE ONSET AND SHORTLY
THEREAFTER...FEEL THE WARM NOSE DEPICTED ON THE RUC AND NAM WILL
BE ENOUGH TO HELP US MIX WITH SLEET QUICKLY...THUS CUTTING DOWN
SNOWFALL AMOUNTS. AT THIS POINT SEE NOTHING MORE THAN A COATING OF
SNOWFALL OVER THE FAR EAST...WITH OUR ADVISORIES JUSTIFIED BY A
COMBINATION OF SLEET AND ESPECIALLY FREEZING RAIN.
AFTER 07Z ENOUGH WARM AIR ALOFT WILL MOVE INTO THE AREA THAT IT
WILL BE JUST A RAIN OR FREEZING RAIN SITUATION...WITH ALL THE
EMPHASIS SHIFTING TO OUR SURFACE TEMPS. OUR NORMALLY COLDER SPOTS
FROM NORTHERN OTSEGO COUNTY INTO THE MOHAWK VALLEY REMAIN AT THE
HIGHEST RISK FOR A PROLONGED PERIOD OF LIGHT FREEZING RAIN. THIS
IS WELL SUPPORTED BY OBS IN THE CENTRAL MOHAWK VALLEY THAT ARE
ALREADY BELOW FREEZING...WITH DEW-POINTS IN THE LOWER TO MIDDLE
20S.
LOOK FOR OUR NEXT UPDATE AROUND 10 PM. IF WE CONTINUE TO SEE TEMPS
ABOVE FREEZING IN NORTHERN PA...WE MAY BE ABLE TO TRIM BACK OUR
ADVISORY FROM SOUTH TO NORTH.
415 PM
UPDATE...TREND FOR A WARMER INCIPIENT BOUNDARY LAYER CONTINUES IN
THE MODELS...AS SYSTEM MOVES IN TONIGHT. THUS I DO NOT SEE A NEED
FOR ANY FURTHER EXPANSION OF CURRENT WINTER WEATHER
ADVISORY...WHICH INCLUDES COUNTIES EAST OF INTERSTATE 81. FOR
COUNTIES ALONG AND WEST OF INTERSTATE 81...HIGH CONFIDENCE NOW
THAT PRECIPITATION TYPE WILL BE ALL RAIN...WITH PERHAPS ONLY A
LITTLE BRIEF SLEET BUT WITH TEMPERATURES STAYING ABOVE FREEZING.
AND OF THE WINTER WEATHER ADVISORY COUNTIES...TRANSITION TO PLAIN
RAIN WILL OCCUR EARLY FOR ALL BUT ONEIDA/DELAWARE/OTSEGO...SO I
MOVED UP THE END TIME FOR THOSE ZONES TO 6 AM. FOR THE EARLIER
ENDING ZONES...ICE AND SNOW ACCUMULATIONS LOOK TO BE FAIRLY LIGHT
AND MAINLY AT HIGHER ELEVATIONS. MANY VALLEY LOCATIONS MAY GET
THROUGH WITH ONLY PLAIN RAIN OR A LITTLE LIGHT SLEET.
COLD AIR WILL LINGER LONGER IN THE NORTHEASTERN ZONES COURTESY OF
COLD AIR DAMMING...SO WINTRY MIX WILL LAST INTO THE MORNING. WE
WILL HAVE TO WATCH CLOSELY FOR ICE ACCUMULATIONS IN EXCESS OF A
QUARTER INCH...IN PARTICULAR TOWARDS THE MOHAWK VALLEY/SOUTHERN
TUG HILL PLATEAU...SHOULD THE COLD AIR TAKE LONG TO SCOUR OUT.
SNOW ACCUMULATIONS MEANWHILE WILL BE OF HIGH WATER
CONTENT...GENERALLY 1 TO 3 INCHES AND MAINLY AT HIGHER ELEVATIONS.
WHATEVER THE TYPE...FOR THE AREA IN GENERAL RAW PRECIPITATION
AMOUNTS WILL RANGE FROM A HALF INCH OR SO IN THE WEST-
NORTHWEST...TO ALMOST AN INCH IN THE SOUTHEAST. AFTER A BRIEF DIP
IN TEMPERATURES EARLY THIS EVENING...LOOKING FOR STEADY TO
SLOWLY RISING TEMPERATURES OVERNIGHT. FINGER LAKES...SOUTHERN
TIER OF NY...AND MOST OF NORTHEAST PA WILL EVENTUALLY GET INTO
THE 40S THURSDAY.
DEEPER MOISTURE EXITS WITH THE OCCLUDED FRONT MIDDAY
THURSDAY...LEAVING LIGHT SHOWERS OR PERHAPS DRIZZLE IN THE
AFTERNOON TO EVENING. BOUNDARY LAYER WILL BE SLOW TO COOL THURSDAY
NIGHT...UNTIL ARRIVAL OF STRONG NEGATIVELY TILTED COLD FRONT
TOWARDS DAWN FRIDAY. SO CHANGEOVER OF ANY REMAINING LIGHT RAIN
SHOWERS TO SNOW...WILL BE GRADUAL.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
UPDATED AS OF 4 PM WED... MODEL CONSENSUS IS FAIRLY GOOD ON SYSTEM
EVOLUTION THIS PD.
A STG COLD FRONT IS SLATED TO CROSS THE FA FROM SW TO NE FRI
AM...GENERALLY IN THE 12-15Z TIME FRAME. QG FORCING IS PRETTY POTENT
WITH THIS FRNT...AS A HEALTHY UPPER-LVL WAVE ACCOMPANIES IT...SO
MOST SXNS SHOULD SEE SHRA/SHSN WITH THE FROPA.
INITIALLY...THE DEEP-LYRD FLOW IS PROGGED TO BE SWLY FRI AFTN
POST-FROPA...SO AS THE LAKES BEGIN TO FIRST RESPOND TO THE INCOMING
COLD AIR...THE BRUNT OF THE LES SHOULD STAY N AND W OF THE
CWA...WITH JUST SCTD -SHSN/FLRYS ANTICIPATED IN CNY/NRN TIER PA.
WINDS SHOULD BE STG AND GUSTY FRI AFTN...WITH DECENT ISALLOBARIC
FORCING AND GOOD MOMENTUM TRANSFER CONDITIONS AT PLAY. ADVSY LVL
WIND GUSTS ARE NOT OUT OF THE QUESTION (35-45 KT)...SPCLY OUR
NRN/WRN ZNS...AND LATER SHIFTS WILL BE TAKING A CLOSER LOOK AT THIS.
FRI NGT AND SAT...AS A SECONDARY SFC TROUGH PUSHES THROUGH...AND
ADDITIONAL UPPER-LVL WAVES TRAVERSE THE RGN...THE BLYR FLOW SHOULD
VEER MORE INTO A 280-300 VECTOR WITH TIME. THIS SHOULD STEER MORE
PERSISTENT LES INTO OUR FA.
THE BEST OPPORTUNITY FOR MORE SIG LES MAY BE RESTRICTED TO A
RELATIVELY NARROW WINDOW FRI NGT...WHEN THE BEST COMBO OF CYCLONIC
FLOW AND DEEPER MOIST/PSBL MULTI-LK INFLUENCE EXISTS. HOWEVER...THE
DETRACTING ELEMENTS OF TRANSITIONAL FLOW AND TERRESTRIAL INSTAB FRI
EVE ALSO SEEM TO BE THERE. TIME WILL TELL ON HOW THIS ALL SHAKES
OUT...BUT WE DO HAVE LIKELY POPS FOR SHSN FROM LATER FRI AFTN INTO
EARLY SAT ACROSS MANY OF OUR NRN ZNS.
AS WE HEAD THRU THE DAY SAT...THE INVERSION SHOULD LWR
SUBSTANTIALLY...WITH THE MOIST SUPPLY ALSO WANING. THUS...MORE
PERSISTENT SHSN SHOULD DIMINISH TO SCTD -SHSN/FLRYS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
3 PM UPDATE...
SATURDAY NIGHT/SUNDAY...850 TEMPS OF -16C TO -18C AND A NORTHWEST
FLOW WILL BE FAVORABLE FACTORS FOR LAKE EFFECT SNOW DURING THIS
TIME BUT A LOW INVERSION (4KFT SATURDAY NIGHT THEN LOWERING
SUNDAY) ALONG WITH DRY AIR WILL INHIBIT MUCH FROM HAPPENING. STILL
WITH COLD AIR IN PLACE EXPECT A FEW FLURRIES OR A BRIEF SNOW
SHOWER ESPECIALLY FROM SYRACUSE DOWN THROUGH THE CORTLAND AREA ON
A 320 FLOW.
SUNDAY NIGHT/MONDAY....HIGH PRESSURE BUILDING SOUTH ACROSS THE
AREA WILL KEEP THIS PERIOD DRY AND QUIET. WITH A BETTER SHOT AT A
CLEAR SKY SUNDAY NIGHT...MORNING LOWS MONDAY WILL BE IN THE SINGLE
DIGITS FOR MOST OF THE AREA WITH READINGS BELOW ZERO OVER THE FAR
EAST AND NORTH.
TUESDAY/WEDNESDAY....AN AREA OF LOW PRESSURE MOVING THROUGH THE
NORTHERN GREAT LAKES STILL LOOKS TO BRING US OUR NEXT SHOT AT
SIGNIFICANT PRECIPITATION. BOTH THE EURO AND GFS ARE PRETTY SIMILAR
WITH THE TRACK BEING WELL TO OUR NORTH AND WEST...BUT THEY DIFFER
ON HOW MUCH WARM AIR IS DRAWN UP AHEAD OF THE SYSTEM. ONE THING IS
FOR SURE...THE COLD AIR WHICH WILL BE IN PLACE THIS UPCOMING
WEEKEND WILL BE RETREATING OUT TO SEA BUT MANY QUESTIONS REMAIN ON
HOW MUCH OF IT REMAINS BEHIND. WITH NO CLEAR-CUT SOLUTION
CONTINUED TO PLAY IT A RAIN/SNOW MIX TUESDAY WITH A TRANSITION TO
SNOW TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
RAIN AND LIGHT FOG WILL PERSIST OVERNIGHT AND INTO THURSDAY
AFTERNOON, KEEPING THE TERMINALS IN MVFR TERRITORY. CEILINGS WILL
RANGE FROM 1500 TO 2500 FEET, WITH VISIBILITIES FLUCTUATING
BETWEEN 3SM AND P6SM AS RAIN BANDS MOVE IN AND OUT.
AT THE HIGHER ELEVATION BGM TERMINAL, BORDERLINE IFR CONDITIONS
WILL HOLD THROUGH AT LEAST LATE MORNING. CEILINGS WILL BE BETWEEN
500 AND 1000 FEET WITH VISIBILITIES BETWEEN 2SM AND 6SM.
WINDS WILL BE GUSTY THROUGH 9Z, WITH OCCASIONAL EAST-SOUTHEAST
GUSTS OF 15 TO 20 KNOTS. WINDS WILL DIE DOWN A BIT TOWARD SUNRISE
AS THE PRESSURE GRADIENT SLACKENS.
RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS LATE THURSDAY NIGHT OR
EARLY FRIDAY MORNING, WITH TEMPO MVFR TO BORDERLINE IFR CONDITIONS
POSSIBLE.
.OUTLOOK...
FRI...GUSTY WINDS AND PSBL RESTRICTIONS IN SHSN...ESPECIALLY
KRME/KSYR.
FRI NGT/SAT...MVFR/IFR IN LAKE-EFFECT SHSN KSYR/KRME...WITH
RESTRICTIONS ALSO PSBL AT KBGM/KITH/KELM.
SUN/MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
PAZ040-048-072.
NY...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NYZ036-045-062.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ009-037-
046-057.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MLJ
LONG TERM...HEDEN
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
229 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL LIFT NORTHWARD ACROSS PENNSYLVANIA
EARLY TODAY WITH STEADY RAINS TAPERING TO SCATTERED SHOWERS BY THE
AFTERNOON. MILD SOUTHWEST WINDS WILL HELP BOOST DAYTIME TEMPERATURES
SEVERAL DEGREES ABOVE NORMAL. A VIGOROUS UPPER LEVEL CLOSED LOW
AND ASSOCIATED ARCTIC FRONTAL BOUNDARY MOVING THROUGH THE OHIO
VALLEY INTO THE NORTHEAST STATES WILL BRING ACCUMULATING SNOWS TO
MUCH OF WESTERN AND CENTRAL PENNSYLVANIA LATER TONIGHT INTO
EARLY FRIDAY. TEMPERATURES WILL DROP RAPIDLY FROM WEST TO EAST BEHIND
STRONG GUSTY WINDS IN THE WAKE OF THE ARCTIC FRONTAL PASSAGE. LAKE
EFFECT AND MOUNTAIN SNOW SHOWERS WILL FOLLOW FOR THE END OF THE
WEEK AND LAST INTO THE WEEKEND...WITH ADDITIONAL SNOW ACCUMULATION
LIKELY. THE COLD AND BRISK WEATHER WILL PERSIST THROUGH THE
WEEKEND AS AN UPPER LEVEL TROUGH GRIPS THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
RADAR SHOWS AREA OF MOD TO LCLY HVY RNFL PIVOTING NWD ACRS THE
CENTRAL MTNS AHEAD OF POTENT SRN STREAM S/W LIFTING THRU THE
VIRGINAS INTO SRN PA. MAIN CHANGE TO NEAR TERM FCST WAS TO ADD
MENTION OF WINTRY MIX IN THE NRN MTNS AS RUC 925-850MB WET BULBS
ARE STILL NEAR 0C. THE ENHANCED PCPN RATES SHOULD AID EVAP COOLING
WITH EITHER IP OR FZRA P TYPES GIVEN WARM LYR ALOFT AND SHALLOW
COLD AIR IN THE 0-1KM LAYER.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM FRIDAY/...
WITH WINDS SHIFTING TO THE SW ON THU...MOST OF THE DAY SHOULD BE
DRY AFTER MID MORNING.
MEAN WHILE A POTENT NRN STREAM CLOSED UPPER TROUGH WILL DIG SEWD
FM THE MID MISSOURI RVR VLY ACRS THE MIDWEST STATES. AT THE
SFC...A COMPLEX FRONTAL BOUNDARY ADJOINING DOUBLE SFC LOWS OVR OH
AND ALONG THE NRN MID-ATLC COAST WILL LIFT NWD THRU PA AND
ADJACENT STATES EARLY IN THE DAY...ALLOWING THE AREA TO BREAK INTO
THE WARM SECTOR AHEAD OF SHARP ARCTIC FRONT SWEEPING THROUGH THE
OH VLY. THE NWD MVMT OF THESE LG SCALE FEATURES SHOULD BRING AN
END TO STEADIER WAA PCPN OVRRNG THE RETREATING COLD SECTOR...WITH
PCPN BCMG MORE SHOWERY IN NATURE BY THURS AFTN. MILD SSWLY WINDS
WILL ADVECT UNSEASONABLY WARM AIR INTO THE REGION HELPING TO PUSH
TEMPS 10 TO 15 DEGREES ABOVE AVERAGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A *HIGH IMPACT SUB ADVISORY* EVENT LOOKS VERY LIKELY LATE THURSDAY
NIGHT THROUGH FRIDAY MORNING...AS ARCTIC AIR ARRIVES PUNCTUATED BY
A 2-3 HOUR BURST OF MODERATE TO HEAVY SNOW IN MANY AREAS. 3HR
TEMPERATURE DROPS BEHIND THE FRONT OF -15F WILL DROP TEMPS FROM
THE MID TO UPPER 30S TO THE LOW TO MID 20S FROM WEST TO EAST...
BEGINNING WITH WESTERN SECTIONS 06Z THU AND ENDING WITH LOWER SUSQ
BY 15Z. UNTREATED ROADS COULD EXPERIENCE FLASH FREEZES UNDER THESE
CONDITIONS.
VIGOROUS CLOSED H5 LOW PIVOTS ENEWD FROM IN/KY ACRS W-CENTRAL PA
INTO NY STATE THU NIGHT AND FRIDAY. STRONG HEIGHT FALLS AND ENHANCED
UVVEL/S VIA LEFT EXIT DYNAMICS ASSOC WITH 125KT UPPER JET ROUNDING
THE BASE OF THE CLOSED H5 LOW WILL CONTRIBUTE TO A "BURST" OF PCPN
OVR THE ALLEGHENIES AND CENTRAL MTNS. RAIN SHOULD QUICKLY
TRANSITION TO SNOW UPON THE ARRIVAL OF MUCH COLDER AIR BEHIND THE
SHARP ARCTIC FRONT...PROMOTING STEEP LAPSE RATES AND RAPID COLUMN
COOLING. MDL QPFS ARE IN PRETTY GOOD AGREEMENT IN GENERATING
0.25-0.50 INCH LIQUID EQUIVALENTS WHICH WOULD TRANSLATE INTO ADVY
TYPE SNOW AMTS FOR MANY AREAS. THEREFORE LIGHT TO MODERATE SNOW
POTENTIAL CURRENTLY HIGHLIGHTED IN HWO.
AS MENTIONED ABOVE...FALLING TEMPERATURES AND STRONG GUSTY WINDS
WILL BE A MAJOR CONCERN WITH THE MODIFIED ARCTIC AIR ARRIVAL. THE
LATEST MDL DATA SUGGESTS A PERIOD OF STRONG WIND GUSTS APPROACHING
40KTS WILL BE POSSIBLE ON FRIDAY IN THE WAKE OF THE ARCTIC FROPA.
STRONG WINDS ALSO HIGHLIGHTED IN THE HWO AND WIND ADVY MAY BE
NEEDED. THE STRONG WINDS COMBINED WITH THE ARRIVAL OF SHARPLY
COLDER AIR WILL DROP WIND CHILLS INTO THE SINGLE DIGITS OVR THE
NORTHERN AND WESTERN MTNS.
FINALLY...YET ANOTHER POTENTIAL HAZARD TO CONSIDER LATER IN THE
PD WILL BE LAKE EFFECT SNOWS FRI-SUN. A FAVORABLE CROSS-LAKE FETCH
SHOULD SET-UP IN THE WAKE OF THE DEEP LOW LIFTING NEWD THRU THE ST
LAWRENCE VLY ON DAY 3...WITH SOME ADDITIONAL LIFT LKLY IN ADVANCE
OF A REINFORCING S/WV TROUGH ROTATING ACRS THE GRT LKS. THE COLD
WNWLY FLOW REGIME WILL ENCOURAGE NMRS LAKE EFFECT SNOW SHOWERS/BANDS
WITH MODERATE ACCUMS POSSIBLE DOWNWIND OF LAKE ERIE OVR THE NW
SNOWBELT AND ON THE RIDGES OF THE LAUREL HIGHLANDS.
AFTER A MILD DAY ON THURSDAY...TEMPERATURES WILL AVG BELOW NORMAL
THROUGH THE REMAINDER OF THE PD. THE LW TROUGH IS FCST TO LIFT
OUT OF THE NE STATES BY EARLY NEXT WEEK. THIS SHOULD LEAD TO A
MODERATION IN TEMPS AS S/WV RIDGE SLIDES EWD FM THE MIDWEST/GRT
LKS. MEDIUM RANGE MDL AND ENSEMBLE GUID SHOWS A N-S SFC RIDGE
MIGRATING EWD OFF THE ECOAST BY NEXT TUES. THIS FEATURE SHOULD
PROVIDE FAIR AND DRY WEATHER TO START NEXT WEEK BEFORE RETURN FLOW
AND APPROACHING FRONT BRING THE NEXT THREAT OF PCPN AROUND MID-
WEEK/JANUARY 18TH.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
WIDESPREAD IFR CIGS AND RAIN EXPECTED EARLY THIS MORNING AS LOW
PRESSURE LIFTS NORTHWARD THRU THE STATE. THE HEAVIEST RAIN AND
LLWS IS ASSOCIATED WITH A LOW LVL JET. THIS FEATURE HAS ALREADY
CLEARED THE S TIER COUNTIES AT 07Z...AND SHOULD LIFT NORTH OF THE
ENTIRE STATE BY DAWN.
CONDS WILL BEGIN TO IMPROVE BY LATE THIS MORNING AND AFTN...AS LOW
PRESSURE DEPARTS THE AREA. THE IMPROVEMENT WILL BE MOST PRONOUNCED
ACROSS THE LOWER ELEVATIONS OF SE PA...WHERE VFR CONDS APPEAR LIKELY
BY AFTN. RESIDUAL LOW LVL MOISTURE ASCENDING THE W MTNS MAY RESULT
IN PERSISTENT LOW CIGS AT BFD AND JST.
A SHARP COLD FRONT WILL SWEEP INTO THE REGION TONIGHT...BRINGING A
PERIOD OF RAIN...CHANGING TO WINDBLOWN SNOW OVR THE W MTNS.
OUTLOOK...
FRI...WINDY WITH MVFR CIGS/SNOW SHOWERS W MTNS.
SAT...MVFR CIGS/SNOW SHOWERS POSSIBLE W MTNS.
SUN-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DEVOIR/MARTIN
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1247 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX FRONTAL SYSTEM WILL LIFT NORTHWARD ACROSS PENNSYLVANIA
EARLY TODAY WITH STEADY RAINS TAPERING TO SCATTERED SHOWERS BY THE
AFTERNOON. MILD SOUTHWEST WINDS WILL HELP BOOST DAYTIME TEMPERATURES
SEVERAL DEGREES ABOVE NORMAL. A VIGOROUS UPPER LEVEL CLOSED LOW
AND ASSOCIATED ARCTIC FRONTAL BOUNDARY MOVING THROUGH THE OHIO
VALLEY INTO THE NORTHEAST STATES WILL BRING ACCUMULATING SNOWS TO
MUCH OF WESTERN AND CENTRAL PENNSYLVANIA LATER TONIGHT INTO
EARLY FRIDAY. TEMPERATURES WILL DROP RAPIDLY FROM WEST TO EAST BEHIND
STRONG GUSTY WINDS IN THE WAKE OF THE ARCTIC FRONTAL PASSAGE. LAKE
EFFECT AND MOUNTAIN SNOW SHOWERS WILL FOLLOW FOR THE END OF THE
WEEK AND LAST INTO THE WEEKEND...WITH ADDITIONAL SNOW ACCUMULATION
LIKELY. THE COLD AND BRISK WEATHER WILL PERSIST THROUGH THE
WEEKEND AS AN UPPER LEVEL TROUGH GRIPS THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
RADAR SHOWS AREA OF MOD TO LCLY HVY RNFL PIVOTING NWD ACRS THE
CENTRAL MTNS AHEAD OF POTENT SRN STREAM S/W LIFTING THRU THE
VIRGINAS INTO SRN PA. MAIN CHANGE TO NEAR TERM FCST WAS TO ADD
MENTION OF WINTRY MIX IN THE NRN MTNS AS RUC 925-850MB WET BULBS
ARE STILL NEAR 0C. THE ENHANCED PCPN RATES SHOULD AID EVAP COOLING
WITH EITHER IP OR FZRA P TYPES GIVEN WARM LYR ALOFT AND SHALLOW
COLD AIR IN THE 0-1KM LAYER.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM FRIDAY/...
WITH WINDS SHIFTING TO THE SW ON THU...MOST OF THE DAY SHOULD BE
DRY AFTER MID MORNING.
MEAN WHILE A POTENT NRN STREAM CLOSED UPPER TROUGH WILL DIG SEWD
FM THE MID MISSOURI RVR VLY ACRS THE MIDWEST STATES. AT THE
SFC...A COMPLEX FRONTAL BOUNDARY ADJOINING DOUBLE SFC LOWS OVR OH
AND ALONG THE NRN MID-ATLC COAST WILL LIFT NWD THRU PA AND
ADJACENT STATES EARLY IN THE DAY...ALLOWING THE AREA TO BREAK INTO
THE WARM SECTOR AHEAD OF SHARP ARCTIC FRONT SWEEPING THROUGH THE
OH VLY. THE NWD MVMT OF THESE LG SCALE FEATURES SHOULD BRING AN
END TO STEADIER WAA PCPN OVRRNG THE RETREATING COLD SECTOR...WITH
PCPN BCMG MORE SHOWERY IN NATURE BY THURS AFTN. MILD SSWLY WINDS
WILL ADVECT UNSEASONABLY WARM AIR INTO THE REGION HELPING TO PUSH
TEMPS 10 TO 15 DEGREES ABOVE AVERAGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A *HIGH IMPACT SUB ADVISORY* EVENT LOOKS VERY LIKELY LATE THURSDAY
NIGHT THROUGH FRIDAY MORNING...AS ARCTIC AIR ARRIVES PUNCTUATED BY
A 2-3 HOUR BURST OF MODERATE TO HEAVY SNOW IN MANY AREAS. 3HR
TEMPERATURE DROPS BEHIND THE FRONT OF -15F WILL DROP TEMPS FROM
THE MID TO UPPER 30S TO THE LOW TO MID 20S FROM WEST TO EAST...
BEGINNING WITH WESTERN SECTIONS 06Z THU AND ENDING WITH LOWER SUSQ
BY 15Z. UNTREATED ROADS COULD EXPERIENCE FLASH FREEZES UNDER THESE
CONDITIONS.
VIGOROUS CLOSED H5 LOW PIVOTS ENEWD FROM IN/KY ACRS W-CENTRAL PA
INTO NY STATE THU NIGHT AND FRIDAY. STRONG HEIGHT FALLS AND ENHANCED
UVVEL/S VIA LEFT EXIT DYNAMICS ASSOC WITH 125KT UPPER JET ROUNDING
THE BASE OF THE CLOSED H5 LOW WILL CONTRIBUTE TO A "BURST" OF PCPN
OVR THE ALLEGHENIES AND CENTRAL MTNS. RAIN SHOULD QUICKLY
TRANSITION TO SNOW UPON THE ARRIVAL OF MUCH COLDER AIR BEHIND THE
SHARP ARCTIC FRONT...PROMOTING STEEP LAPSE RATES AND RAPID COLUMN
COOLING. MDL QPFS ARE IN PRETTY GOOD AGREEMENT IN GENERATING
0.25-0.50 INCH LIQUID EQUIVALENTS WHICH WOULD TRANSLATE INTO ADVY
TYPE SNOW AMTS FOR MANY AREAS. THEREFORE LIGHT TO MODERATE SNOW
POTENTIAL CURRENTLY HIGHLIGHTED IN HWO.
AS MENTIONED ABOVE...FALLING TEMPERATURES AND STRONG GUSTY WINDS
WILL BE A MAJOR CONCERN WITH THE MODIFIED ARCTIC AIR ARRIVAL. THE
LATEST MDL DATA SUGGESTS A PERIOD OF STRONG WIND GUSTS APPROACHING
40KTS WILL BE POSSIBLE ON FRIDAY IN THE WAKE OF THE ARCTIC FROPA.
STRONG WINDS ALSO HIGHLIGHTED IN THE HWO AND WIND ADVY MAY BE
NEEDED. THE STRONG WINDS COMBINED WITH THE ARRIVAL OF SHARPLY
COLDER AIR WILL DROP WIND CHILLS INTO THE SINGLE DIGITS OVR THE
NORTHERN AND WESTERN MTNS.
FINALLY...YET ANOTHER POTENTIAL HAZARD TO CONSIDER LATER IN THE
PD WILL BE LAKE EFFECT SNOWS FRI-SUN. A FAVORABLE CROSS-LAKE FETCH
SHOULD SET-UP IN THE WAKE OF THE DEEP LOW LIFTING NEWD THRU THE ST
LAWRENCE VLY ON DAY 3...WITH SOME ADDITIONAL LIFT LKLY IN ADVANCE
OF A REINFORCING S/WV TROUGH ROTATING ACRS THE GRT LKS. THE COLD
WNWLY FLOW REGIME WILL ENCOURAGE NMRS LAKE EFFECT SNOW SHOWERS/BANDS
WITH MODERATE ACCUMS POSSIBLE DOWNWIND OF LAKE ERIE OVR THE NW
SNOWBELT AND ON THE RIDGES OF THE LAUREL HIGHLANDS.
AFTER A MILD DAY ON THURSDAY...TEMPERATURES WILL AVG BELOW NORMAL
THROUGH THE REMAINDER OF THE PD. THE LW TROUGH IS FCST TO LIFT
OUT OF THE NE STATES BY EARLY NEXT WEEK. THIS SHOULD LEAD TO A
MODERATION IN TEMPS AS S/WV RIDGE SLIDES EWD FM THE MIDWEST/GRT
LKS. MEDIUM RANGE MDL AND ENSEMBLE GUID SHOWS A N-S SFC RIDGE
MIGRATING EWD OFF THE ECOAST BY NEXT TUES. THIS FEATURE SHOULD
PROVIDE FAIR AND DRY WEATHER TO START NEXT WEEK BEFORE RETURN FLOW
AND APPROACHING FRONT BRING THE NEXT THREAT OF PCPN AROUND MID-
WEEK/JANUARY 18TH.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
WIDESPREAD MVFR/IFR EXPECTED OVERNIGHT INTO THURSDAY AS THE SFC
LOW APPROACHES AND MOVES THRU. I DID KNOCK THE SFC WINDS DOWN AS
STRONG COLD AIR DAMMING IS LEADING TO A VERY STABLE BOUNDARY LAYER
AND CAPPING WIND IN THE 10-15 MPH RANGE FOR THE MOST PART. THIS
COULD PROMOTE SOME LLWS AS A 30-50KT LOW LEVEL JET ROARS IN
OVERNIGHT.
CONDITIONS WILL BEGIN TO IMPROVE THURSDAY MORNING AND AFTERNOON
AS LOW PRESSURE DEPARTS THE AREA. GUIDANCE HINTS AT A SECOND SPOKE
OF ENERGY ROTATING AROUND THE UPPER-LOW AND PUSHING A BIT MORE
PRECIP ACROSS AREA THURS NIGHT ALONG AND IN THE WAKE OF A
RELATIVELY STRONG COLD FRONT. PERIODS OF MVFR TO IFR IN SNOW WILL
BE LIKELY...ESPECIALLY ACROSS THE NRN AND WRN MTNS OF PA.
NW FLOW WILL SET UP FRI INTO SAT BEHIND DEPARTING SYSTEM...WHICH
WILL CAUSE SOME LAKE-EFFECT/UPSLOPE SNOW SHOWERS ACROSS MAINLY
THE NORTH AND WEST.
OUTLOOK...
THU...LOW PRESSURE DEPARTS AREA. DEVELOPING UPSLOPE
FLOW MAY HOLD MVFR CONDS NORTH AND WEST.
FRI-SAT...NW FLOW WITH MVFR POSS IN SCTD -SHSN MAINLY NORTH AND
WEST.
SUN-MON...GENERALLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DEVOIR/MARTIN
LONG TERM...RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1134 PM CST WED JAN 11 2012
.AVIATION...
BREEZY CONDITIONS WILL PERSIST FOR MUCH OF THE OVERNIGHT AT KCDS
WITH A RETURN TO WINDY CONDITIONS DURING THE AFTERNOON. WINDS MAY
BECOME BREEZY AT KLBB DURING THE AFTERNOON BUT WILL GO LIGHT BY
EARLY IN THE EVENING.
&&
PREV DISCUSSION... /ISSUED 352 PM CST WED JAN 11 2012/
SHORT TERM...
THE SURFACE PRESSURE GRADIENT SUPPORTING TODAYS STIFF NORTHERLY
WINDS IS EXPECTED TO EASE STEADILY THIS EVENING...WITH DROP IN MOST
SURFACE WIND SPEEDS NEAR OR PRIOR TO 00Z THIS EVENING. OUR PLAN IS
TO ALLOW THE WIND ADVISORY TO RUN ITS COURSE UNTIL 00Z WITH NO
EXTENSION. WINDS PROBABLY WILL BE SLOWEST TO DROP THIS EVENING OVER
THE ROLLING PLAINS AND MAY RETAIN GREATER THAN 10 MPH WINDS UNTIL
CLOSE TO DAYBREAK ON THURSDAY. THIS SHOULD KEEP ESPECIALLY THE
SOUTHERN ROLLING PLAINS BETTER MIXED WHILE LOW TEMPERATURES
OTHERWISE TONIGHT SHOULD DROP INTO TEENS ON MOST OF THE CAPROCK AND
LOW TO MID 20S OVER ROLLING PLAINS. THE UPPER FLOW SHOULD REMAIN
SLIGHTLY ANTICYCLONICALLY CURVED IN NORTHWEST FLOW ALOFT WITH A
BRANCH OF THE POLAR JET STILL OVER THE AREA UNTIL MIDDAY THURSDAY.
THIS MAY LEAD TO AREAS OF MID CLOUDS AGAIN LATER TONIGHT AND/OR
THROUGH THURSDAY...THOUGH SOMEWHAT DIFFICULT TO ANTICIPATE. LOW
CLOUDS TONIGHT ALSO SOMEWHAT UNCERTAIN GIVEN PREDOMINANT NORTHERLY
LOW LEVEL FLOW AND VERY DRY AIR...THOUGH RUC INDICATES ABOUT 20
DEGREES MORE NORTHEAST COMPONENT AND MAINTAINS MORE H850 LAYER
MOISTURE ACROSS NORTHERN AND EASTERN ZONES. SO...APPEARS PERHAPS
BEST AREAS FOR MVFR LAYER LOW CLOUDS WOULD BE ACROSS NORTHEAST ZONES
BUT CANT RULE OUT FOR CENTRAL. EITHER WAY...A CHILLY NIGHT WILL
OCCUR WITH A FLATTER SURFACE PRESSURE GRADIENT DOMINATING THROUGH
MUCH OF THURSDAY. TRENDED HIGHS THURSDAY VERY SLIGHTLY UPWARDS ALONG
LINES OF GUIDANCE TRENDS AS WELL. RMCQUEEN
LONG TERM...
EXPECT DRY CONDITIONS AND MODERATING TEMPERATURES LATE WEEK ON
THROUGH THE WEEKEND. INITIALLY...A SHORTWAVE TROUGH EMBEDDED WITHIN
NORTHWESTERLY FLOW ALOFT WILL TRAVERSE THE AREA FRIDAY. THIS
DISTURBANCE WILL GENERATE AREAS OF MID/HIGH CLOUD BUT LITTLE ELSE.
THE NORTHWESTERLY FLOW WILL BACK WITH TIME WITH A PROGRESSIVE UPPER
RIDGE TRANSLATING OVER SATURDAY NIGHT AND SUNDAY. THIS
PATTERN...COMBINED WITH INCREASING SOUTHERLY/SOUTHWESTERLY LOW-
LEVEL FLOW...WILL PUSH HIGHS BACK ABOVE AVERAGE OVER THE WEEKEND
/LIKELY ECLIPSING THE 60 DEGREE MARK BY SUNDAY/. ONE MINOR CAVEAT
REVOLVE AROUND A CLIPPER SYSTEM DIVING INTO THE UPPER MIDWEST THAT
MAY ATTEMPT TO BACKDOOR A WEAK COLD FRONT INTO THE NORTHEAST ZONES
ON SATURDAY. EVEN IF THIS FRONT DOES MAKE IT INTO THE AREA...ONLY
MINOR IMPACTS ARE EXPECTED. THUS...HAVE TRENDED FORECAST
TEMPERATURES UP A NOTCH OVER THE WEEKEND.
ATTENTION WILL THEN TURN TO ANOTHER SHORTWAVE TROUGH /THE REMNANTS
OF THE CUTOFF LOW CURRENTLY SPINNING WELL OFF THE CALIFORNIA COAST/
THAT WILL RACE BY THE REGION IN NEAR ZONAL FLOW ALOFT ON MONDAY.
UNFORTUNATELY THE PROGRESSIVE AND OPENING/WEAKENING NATURE OF THE
SYSTEM...ALONG WITH THE DEARTH OF LOW-LEVEL MOISTURE TO WORK
WITH...WILL LIKELY KEEP THIS SYSTEM A DRY ONE LOCALLY. HOWEVER...IF
YOU LIKE WIND YOU MAY BE IN STORE FOR ANOTHER TREAT AS THE LATEST
GUIDANCE AND RAW NWP MODEL OUTPUT SUGGEST WESTERLY WINDS MAY
APPROACH OR EXCEED ADVISORY LEVELS DURING THE DAY MONDAY.
HENCE...HAVE TRENDED WINDS SPEEDS UPWARD IN THE GRIDS...THOUGH A
TOUCH BELOW ADVISORY LEVELS AT THIS POINT. THESE WINDS COULD ALSO
LOFT A BIT OF BLOWING DUST /LIKE TODAY/ AND ALSO ELEVATE THE FIRE
DANGER. HOWEVER...CURRENT PROJECTIONS DO KEEP HUMIDITIES ABOVE MORE
CRITICAL THRESHOLDS...THOUGH THIS COULD BE A BIT OPTIMISTIC AS IS
OFTEN THE CASE IN THE STRONG WESTERLY FLOW REGIME.
BEYOND MONDAY...A COLD FRONT IS PROGGED TO MOVE THROUGH EARLY
TUESDAY...DROPPING TEMPERATURES TOWARD MORE SEASONAL LEVELS. THE
LATEST ROUND OF MODEL SOLUTIONS HAVE TRENDED A LITTLE STRONGER WITH
THE FRONT...PUSHING IT THROUGH THE ENTIRE FA...AND HAVE FOLLOWED
SUITE IN THE GRIDS. THIS COOL-DOWN SHOULD BE RELATIVELY SHORT-LIVED
THOUGH AS THE SFC RIDGE IS QUICKLY SHUNTED EASTWARD UNDER MODERATE
TO STRONG MID-LEVEL ZONAL FLOW IN PLACE ACROSS MUCH OF THE CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 16 41 18 47 23 / 10 0 0 0 0
TULIA 17 42 17 49 22 / 10 0 0 0 0
PLAINVIEW 18 42 19 50 23 / 10 0 0 0 0
LEVELLAND 19 43 21 51 25 / 10 0 0 0 0
LUBBOCK 19 43 21 51 23 / 10 0 0 0 0
DENVER CITY 21 42 23 49 26 / 0 0 0 0 0
BROWNFIELD 22 43 23 50 25 / 0 0 0 0 0
CHILDRESS 23 45 20 53 24 / 10 0 0 0 0
SPUR 24 46 23 53 26 / 10 0 0 0 0
ASPERMONT 25 46 25 54 25 / 10 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS ALBANY NY
832 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX STORM SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION
TO EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY. THE
PRECIPITATION WILL TRANSITION TO RAINFALL DURING THIS MORNING FROM
THE CAPITAL REGION AND THE MOHAWK VALLEY SOUTH AND EAST...AS A
COASTAL LOW QUICKLY MOVES NORTHEAST OF LONG ISLAND. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE OHIO VALLEY TONIGHT
INTO FRIDAY WITH MAINLY RAIN AND SNOW SHOWERS SOUTH AND MIXED
PRECIPITATION TRANSITIONING TO SNOW NORTH...AS WELL AS BLUSTERY
AND COLD CONDITIONS TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 830 AM...THE FIRST BIG BATCH OF PRECIPITATION...MAINLY AS SNOW
FROM ALBANY NORTH...MIX FURTHER SOUTH...HAS LIFTED NORTHWARD. THIS
WAS ASSOCIATED WITH THE FRONTOGENETIC FORCING.
ANOTHER BATCH OF PRECIPITATION WAS WORKING UP THE HUDSON
VALLEY...ASSOCIATED WITH THE ACTUAL UPPER LEVEL LOW. WE HONESTLY ARE
NOT SURE WHAT EXACT FORM THIS PRECIPITATION WAS FALLING. SUSPECT
MAINLY RAIN...MIXED WITH POCKETS OF FREEZING RAIN AND SLEET. HOWEVER
IT MOVES NORTHWARD...IT COULD TRANSLATE BACK TO SNOW FROM ALBANY
NORTH BASED ON OUR SOUNDING. WHILE TEMPERATURES AT ALBANY HAVE
SLIPPED ABOVE FREEZING...THE FREEZING LEVEL IS QUITE...ONLY A 1000
FEET OR SO OFF THE GROUND...SO IT WOULDN`T TAKE MUCH MELTING
SNOWFLAKES TO COOL THE COLUMN.
UPDATED FORECAST TO REFLECT CURRENT TRENDS BUT DECIDED TO LEAVE ALL
FLAGS UP FOR NOW. THUS FAR...FREEZING RAIN HAS NOT BE
PREVALENT...BUT MORE OF RAIN/SNOW SITUATION (WITH A LITTLE SLEET AS
WELL).
********PREVIOUS NEAR TERM FORECAST********
AS OF 7 AM EST...995 MB COASTAL LOW WAS LOCATED NEAR CAPE MAY WITH
THE PRIMARY LOW BACK ACROSS NORTHERN OHIO. BULK OF PCPN WITH THE
MAIN SURGE OF PCPN HAS TAPERED OFF FROM THE CAPITAL DISTRICT SOUTH
TEMPORARILY ALTHOUGH NEXT SURGE OF PCPN MAINLY IN THE FORM OF RAIN
ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS MOVING ACROSS
NORTHERN NEW JERSEY AND NORTHEAST PA. WILL LEAVE REMAINING
ADVISORIES IN PLACE FOR NOW AS STILL SOME MIXED PRECIPITATION
FALLING. AREAS TO THE NORTHWEST WHICH ARE STILL BELOW FREEZING
HAVE REPORTED A PROLONGED PERIOD OF SLEET AND FREEZING RAIN
ESPECIALLY ACROSS THE WESTERN MOHAWK VALLEY AND PORTIONS OF THE
WESTERN ADIRONDACKS. HAVE ADJUSTED HOURLY GRIDS TO BETTER FIT
CURRENT OBS AND RADAR TRENDS. ALSO HAVE ADJUSTED QPF...SNOW AND
ICE AMOUNTS SLIGHTLY TO REFLECT LATEST REPORTS AS WELL AS EXPECTED
ADDITIONAL AMOUNTS. BULK OF THE MIXED PCPN IS EXPECTED TO BE OVER
BY THE END OF THE MORNING COMMUTE EXCEPT ACROSS FAR NORTHERN AREAS
AND WILL KEEP ADVISORY UP THROUGH THE AFTERNOON AT THIS TIME FOR
THE SOUTHERN ADIRONDACKS.
AS OF 4 AM EST...995 MB COASTAL LOW HAS MOVED OVER THE DELMARVA
PENINSULA AND IS TRACKING TOWARD LONG ISLAND AS THE PRIMARY LOW TO
THE WEST REMAINS OVER NORTH CENTRAL OHIO. TEMPERATURES HAVE COOLED
ACROSS MOST OF THE CENTRAL PORTION OF THE FA DURING THE LAST FEW
HOURS AS DEWPOINTS HAVE RISEN. FAR NORTHERN PORTIONS OF THE FA
HAVE SEEN TEMPS AND DEWPOINTS RISE WITH FAR SOUTHEAST PORTION OF
FA NOT ABLE TO TAP ENOUGH COLD AIR TO SUPPORT MUCH IN THE WAY OF
MIXED PCPN WITH MOSTLY RAIN OCCURRING. PARTIAL THICKNESS
VALUES...MODEL SOUNDINGS AND HRRR TEMPS ALL SUPPORT A GRADUAL
TRANSITION DURING THE MORNING TO ALL RAIN EXCEPT ACROSS THE
SOUTHERN ADIRONDACKS WHERE A WINTRY MIX WILL CONTINUE INTO THE
AFTERNOON. BEST FRONTOGENESIS IS NOW OCCURRING ACROSS THE
NORTHERN HALF OF FA AND THIS WILL SLIDE NORTH AND EAST OF THE FA
BY 12Z. ALREADY SEEING SOME BREAKS IN THE PCPN OCCURRING ACROSS
FAR SOUTHEAST PORTION OF FA AND EXPECT THAT THIS WILL CAUSE PCPN
TO DIMINISH IN INTENSITY FROM SOUTH TO NORTH OVER THE NEXT SEVERAL
HOURS...ALTHOUGH ONE MORE ROUND OF FAIRLY INTENSE PCPN IS
EXPECTED ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS LATER THIS
MORNING. HAVE ADJUSTED POPS TO REFLECT RADAR TRENDS...PTYPE
ADJUSTED BY PARTIAL THICKNESS VALUES GOING CLOSER TO MAV WITH
FORECAST ESSENTIALLY BACK TO THAT WHICH WAS ISSUED AT 4 AM
YESTERDAY. SNOW AMOUNTS WERE GENERALLY CREATED USING A SNOW TO
LIQUID RATIO OF 6:1. HIGHEST SNOWFALL ACCUMULATIONS WILL BE IN THE
MOUNTAINS WHERE 2 TO 6 INCHES OF SNOW IS EXPECTED...HIGHEST TOTALS
OVER SOUTHERN GREEN MOUNTAINS WITH GENERALLY AN INCH OR TWO IN THE
VALLEYS. ICE ACCRETION WILL GENERALLY BE AN INCH OR LESS EXCEPT UP
TO A QUARTER OF AN INCH IS POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS.
EXPECT TEMPS TO SLOWLY RISE FROM CURRENT VALUES IN THE MID TO
UPPER 20S NORTH AND LOW TO MID 30S SOUTH TO THE LOW TO MID 30S
NORTH AND UPPER 30S TO MID 40S SOUTH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
PSEUDO WARM FRONT LIFTS NORTHWARD THURSDAY EVENING AS MID LEVEL DRY
SLOT ADVANCES NORTHWARD ACROSS THE REGION. BUFR PROFILES DO SUGGEST
AMPLE LOW LEVEL MOISTURE WHICH WILL BE CLOSE TO THE -10C ALOFT FOR
ENOUGH ICE NUCLEI TO WARRANT THE LOW CHANCE POPS FOR THE REGION
OVERNIGHT. MAIN DYNAMICS WITH OHIO VALLEY SYSTEM BEGINS TO ENCROACH
OUR WESTERN ZONES WELL AFTER MIDNIGHT WHERE WE WILL INCREASE POPS.
THERMAL PROFILES WILL REMAIN A CHALLENGE...ESPECIALLY FOR PORTIONS
OF THE MOHAWK VALLEY AND DACKS WHERE SURFACE TEMPERATURES ARE
EXPECTED TO DROP BACK INTO THE UPPER 20S AND LOWER 30S. THIS POSES
A PROBLEM WITH THE CHANCE FOR FREEZING RAIN/DRIZZLE DUE TO THE
AFOREMENTIONED POTENTIAL LACK OF ICE NUCLEI.
POTENT MID LEVEL JET COINCIDING WITH IMPRESSIVE FRONTOGENESIS WILL
MAKE FOR AN INTERESTING WEATHER ON FRIDAY MORNING. QG DIAGNOSTIC
FIELDS ARE IMPRESSIVE WITH RAPIDLY INCREASING VERTICAL VELOCITIES
OVER THE CWA AND STEEPENING MID LEVEL LAPSE RATES. WOULD NOT BE
SURPRISED TO FIND A FEW SQUALLS EMBEDDED ALONG THE ARCTIC COLD FRONT
THAT WILL MOVE EAST OF THE CWA BY LATE MORNING FRIDAY /AS SUGGESTED
IN THE EXPERIENTIAL HIRES WINDOWS OF MESOSCALE MODELS/. IN
FACT...TEMPERATURES IN THE WAKE OF THE FROPA SHOULD DROP BACK BELOW
FREEZING WHICH COULD RESULT IN BLACK ICE FORMATION WHERE SURFACES
ARE NOT TREATED. LINGERING SURFACE TROUGH AXIS AND DEFORMATION
DYNAMICS OVER WESTERN AND EASTERN NY COULD PROLONG THE SNOWFALL
WHICH WILL BE MONITORED CLOSELY. FURTHERMORE...LAKE ONTARIO
CONTRIBUTION IS EXPECTED TO INCREASE FRIDAY AFTERNOON INTO FRIDAY
NIGHT WITH A 270-280 WIND DIRECTION AND INCREASING LAKE DELTA T/S.
SEVERAL INCHES OF SNOW /AND BLOWING SNOW/ ARE POSSIBLE FOR PORTIONS
OF THE MOHAWK VALLEY...SOUTHERN DACKS. DUE TO FORECAST CHALLENGES
THAT REMAIN WITH RESPECT TO THE WIND TRAJECTORIES AND THE TIMING OF
THE INVERSION LEVELS DROPPING BELOW 5K FEET...WE WILL NOT HOIST ANY
HEADLINES AT THE PRESENT TIME. WE WILL HIGHLIGHT IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVER THE WEEKEND...THE NORTHEAST WILL BE DOMINATED BY A LARGE SCALE
TROUGH. THIS WILL KEEP TEMPS A LITTLE COOLER THAN THEY HAVE BEEN
RECENTLY AND SOMEWHAT BELOW NORMAL. HOWEVER...IT WON/T BE BRUTALLY
COLD BY ANY STRETCH. THE 12 UTC GEFS IS SHOWING 850 HPA TEMPS
GENERALLY NEAR NORMAL...WITH A BRIEF PERIOD OF ABOUT 1-2 STD BELOW
NORMAL. THE LATEST DETERMINISTIC 12 UTC GFS IS SHOWING 850 HPA
TEMPS OF AROUND -15 DEGREES C FOR SATURDAY...AND -16 TO -18 DEGREES
ON SUNDAY. THIS WILL TRANSLATE TO MAX TEMPS IN THE 20S TO LOW 30S ON
SATURDAY...AND MAX TEMPS IN THE TEENS TO LOW 20S FOR SUNDAY. MIN
TEMPS ON SAT AND SUN NIGHTS WILL GENERALLY BE IN THE SINGLE
DIGITS...WITH BELOW ZERO READINGS ACROSS THE HIGH TERRAIN. WHILE
THIS WILL PROBABLY WIND UP BEING SOME OF THE COLDER NIGHTS OF THE
SEASON SO FAR...IT/S STILL NOT FAR FROM WHAT IS CONSIDERED NORMAL OR
EXPECTED FOR THIS TIME OF THE YEAR.
IT WILL REMAIN FAIRLY DRY OVER THE WEEKEND. THE CYCLONIC FLOW MAY
ALLOW FOR SOME CLOUDS...ESP IN AREAS DOWNWIND OF LAKE ONTARIO.
HOWEVER...THE FLOW WON/T BE OVERLY CONDUCIVE FOR LAKE EFFECT...AND
INVERSION HEIGHTS OF ONLY AROUND 1 KM WILL KEEP ANY LAKE EFFECT SNOW
SHOWERS AS FAIRLY LIGHT AND CONFINED CLOSE TO THE LAKE SHORE. WILL
ONLY ALLOW A BRIEF PERIOD CHC POPS FOR PARTS OF THE MOHAWK
VALLEY/SCHOHARIE COUNTY FOR SAT MORNING...BEFORE LOWERING POPS TO
SLIGHT CHC FOR THE REMAINDER OF SATURDAY.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR MONDAY. THIS WILL
CONTINUE THE DRY WEATHER. TEMPS WILL CONTINUE TO BE A LITTLE ON THE
COOL SIDE...BUT NOTHING UNHEARD OF FOR MID JANUARY...WITH 20S FOR
MOST AREAS. SOME CLOUDS WILL BEGIN TO INCREASE FOR MONDAY NIGHT
AHEAD OF AN APPROACHING STORM SYSTEM. MIN TEMPS MAY ACTUALLY WIND
UP BEING EARLIER IN THE NIGHT...AS TEMPS MAY SLOWLY RISE OVERNIGHT
WITH AN INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW. FOR NOW...HAVE
GONE WITH MIN TEMPS IN THE TEENS IN MOST AREAS.
A STRENGTHENING LOW PRESSURE AREA WILL RACE FROM THE UPPER GREAT
LAKES TOWARDS NORTHERN QUEBEC ON TUESDAY. AN ARCTIC FRONT ASSOCIATED
WITH THIS STORM SYSTEM WILL SWING THROUGH OUR AREA ON TUESDAY. THIS
WILL ALLOW FOR SOME RAIN/SNOW SHOWERS...WITH P-TYPE DEPENDENT ON
ELEVATION/BOUNDARY LAYER TEMPS. MOST VALLEY AREAS WILL PROBABLY WARM
UP JUST ENOUGH TO KEEP MOST OF THE PRECIP AS RAIN...ESP CONSIDERING
THIS STORM IS COMING FROM THE WEST WITH A STORM SYSTEM TRACKING WELL
NORTH OF THE AREA. TEMPS LOOK TO REACH THE 30S IN VALLEY
AREAS...WITH MAX TEMPS IN THE UPPER 20S TO NEAR FREEZING IN THE HIGH
TERRAIN. PRECIP WILL BE SHOWERY IN NATURE AND QPF WILL BE RATHER
LIGHT...WITH LESS THAN A QUARTER OF AN INCH IN MOST AREAS.
IN THE WAKE OF THIS SYSTEM...COOLER AIR WILL AGAIN FILTER INTO THE
REGION FOR TUESDAY NIGHT INTO WEDNESDAY. SOME LAKE EFFECT COULD
AFFECT FAR WESTERN AREAS. TEMPS LOOK TO GO BACK BELOW NORMAL FOR
WEDNESDAY...WITH MAINLY TEENS AND 20S FOR MAX TEMPS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 800 AM...THE HEAVIEST PRECIPITATION HAS MOVED NORTH OF THE
TERMINALS. HOWEVER...THERE ARE MORE SHOWERS OF MAINLY RAIN WORKING
TOWARD KPOU.
REMOVED LLWS FROM KPOU SINCE THEY ARE REPORTING WIND GUSTS TO NEAR
20KTS AND THE ALY RAOB INDICATED THE WIND AT 2000 FEET AROUND 35KT
(NOT 45KTS). NARROWED THE TIME OF LLWS FROM MID TO LATER MORNING AT
KALB AND KGFL AS THAT IS WHEN THE STRONGEST WIND ALOFT MOVE THROUGH.
ALSO REMOVED ANY MENTION OF FREEZING RAIN FROM KGFL.
IFR/MVFR STRADDLE AT BOTH KALB AND KGFL BUT AS PCPN CHANGES TO RAIN
MVFR CONDITIONS WILL PREVAIL. WILL KEEP CIGS PREVAILING AT 2000 FEET
OR LESS ALTHOUGH WITH A DOWNSLOPING WIND...EVEN THESE MIGHT
OCCASIONALLY RISE UP TO VFR AS THEY DID AT KALB JUST BEFORE 800 AM.
OUR INCOMING 12Z RAOB STILL INDICATED A PRETTY STRONG ESE WIND OFF
THE DECK AT AROUND 1500 FEET. HOWEVER...IT MIGHT BE QUITE A STRONG
AS FORECASTED BY THE MODELS. WE WILL REVIEW THE LOW LEVEL WIND SHEAR
ASPECT WHEN THE ENTIRE RAOB COMES THROUGH. FOR NOW...CONTINUE WITH
LOW LEVEL WIND SHEAR UP TO 2000 FEET WITH AN E OR ESE WIND AROUND
40/45KTS THROUGH MUCH OF THE MORNING.
EVEN AFTER THE SYSTEM PASSED BY LATER TODAY...WE SHOULD HOLD ONTO
MVFR CLOUDS THROUGH MUCH OF THE NIGHT. AS LONG THAT HAPPENS...ANY
IFR FOG SHOULD BE LIMITED. HOWEVER...CONFIDENCE IN THIS THINKING IS
ONLY MODERATE...SO THIS PORTION OF THE TAF COULD CHANGE WITH
TIME.
ANOTHER UPPER LEVEL DISTURBANCE AND COLD FRONT WILL LIKELY BRING
ANOTHER ROUND OF RAIN SHOWERS ON FRIDAY...SWITCHING TO SNOW SHOWERS
AS THE DAY WEARS ON. THE WIND WILL PICK UP FROM THE WEST AND THERE
COULD EVEN BE SOME MORE INTENSE SNOW SQUALLS.
OUTLOOK...
FRI-FRI NT...MVFR/IFR...RAIN OR MIXED PRECIPITATION ENDING AS
SNOW. BECOMING WINDY.
SAT-MON...VFR...NO SIG WX.
&&
.HYDROLOGY...
A COMPLEX STORM SYSTEM CURRENTLY IMPACTING THE FA WILL CONTINUE TO
BRING MIX PRECIPITATION TO THE HYDROLOGIC SERVICE AREA THIS MORNING
TRANSITIONING TO ALL RAIN...ESPECIALLY SOUTH AND EAST OF THE SOUTHERN
ADIRONDACKS BY THE AFTERNOON. THE PRECIPITATION WILL BE ASSOCIATED
WITH A COASTAL OR SECONDARY LOW THAT WILL MOVE NORTHEAST OF LONG
ISLAND BY THIS AFTERNOON. THE PRIMARY LOW WILL REMAIN TO THE WEST
OVER THE OHIO VALLEY AND THE GREAT LAKES REGION. TOTAL LIQUID
EQUIVALENT VALUES WILL RANGE FROM A HALF AN INCH TO AROUND AN INCH
BY THURSDAY EVENING. WE ARE EXPECTING SOME DOWNSLOPING TO REDUCE
TOTAL QPF AMOUNTS TO AROUND A HALF AN INCH TO TWO THIRDS OF AN INCH
IN THE UPPER HUDSON VALLEY...AND PORTIONS OF THE LAKE GEORGE REGION.
THE HEAVIEST QPF WILL TEND TO BE SOUTH AND WEST OF THE CAPITAL
REGION. WE ARE EXPECTING MINIMAL IMPACT ON THE MAIN STEM RIVERS WITH
SOME MINOR RISES AT BEST. MOST OF THE PRECIPITATION WILL FALL AS
SNOW...SLEET AND FREEZING RAIN OVER THE NORTHERN BASINS.
TONIGHT...A BRIEF LULL WILL OCCUR BETWEEN THE SYSTEMS...WITH A
DRY SLOT. THERE MIGHT BE SOME SPOTTY FREEZING RAIN OR DRIZZLE
NORTH AND WEST OF THE CAPITAL REGION WITH SPOTTY PLAIN RAIN SOUTH
AND EAST. THE NEXT STRONG UPPER LEVEL DISTURBANCE WILL BRING RAIN
AND SNOW SHOWERS ON FRIDAY....AS IT MOVES OVER UPSTATE NY. THERE
COULD EVEN BE A FEW INTENSE SNOW SQUALLS. TOTAL QPF FROM THIS
SYSTEM LOOKS LIKE TWO TENTHS OF AN INCH SOUTHEAST TO TWO THIRDS OF
AN INCH NORTHWEST. COLDER AIR AND LAKE EFFECT SNOW SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR CTZ001.
NY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ038>041-
043-047>054-058-061-063-082>084.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ032-
033-042.
MA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
WIND ADVISORY UNTIL NOON EST TODAY FOR MAZ001.
VT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
WIND ADVISORY UNTIL NOON EST TODAY FOR VTZ013-014.
&&
$$
SYNOPSIS...11/NAS
NEAR TERM...HWJIV/11
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
800 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX STORM SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION
TO EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY. THE
PRECIPITATION WILL TRANSITION TO RAINFALL DURING THIS MORNING FROM
THE CAPITAL REGION AND THE MOHAWK VALLEY SOUTH AND EAST...AS A
COASTAL LOW QUICKLY MOVES NORTHEAST OF LONG ISLAND. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE OHIO VALLEY TONIGHT
INTO FRIDAY WITH MAINLY RAIN AND SNOW SHOWERS SOUTH AND MIXED
PRECIPITATION TRANSITIONING TO SNOW NORTH...AS WELL AS BLUSTERY
AND COLD CONDITIONS TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 7 AM EST...995 MB COASTAL LOW WAS LOCATED NEAR CAPE MAY WITH
THE PRIMARY LOW BACK ACROSS NORTHERN OHIO. BULK OF PCPN WITH THE
MAIN SURGE OF PCPN HAS TAPERED OFF FROM THE CAPITAL DISTRICT SOUTH
TEMPORARILY ALTHOUGH NEXT SURGE OF PCPN MAINLY IN THE FORM OF RAIN
ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS MOVING ACROSS
NORTHERN NEW JERSEY AND NORTHEAST PA. WILL LEAVE REMAINING
ADVISORIES IN PLACE FOR NOW AS STILL SOME MIXED PRECIPITATION
FALLING. AREAS TO THE NORTHWEST WHICH ARE STILL BELOW FREEZING
HAVE REPORTED A PROLONGED PERIOD OF SLEET AND FREEZING RAIN
ESPECIALLY ACROSS THE WESTERN MOHAWK VALLEY AND PORTIONS OF THE
WESTERN ADIRONDACKS. HAVE ADJUSTED HOURLY GRIDS TO BETTER FIT
CURRENT OBS AND RADAR TRENDS. ALSO HAVE ADJUSTED QPF...SNOW AND
ICE AMOUNTS SLIGHTLY TO REFLECT LATEST REPORTS AS WELL AS EXPECTED
ADDITIONAL AMOUNTS. BULK OF THE MIXED PCPN IS EXPECTED TO BE OVER
BY THE END OF THE MORNING COMMUTE EXCEPT ACROSS FAR NORTHERN AREAS
AND WILL KEEP ADVISORY UP THROUGH THE AFTERNOON AT THIS TIME FOR
THE SOUTHERN ADIRONDACKS.
AS OF 4 AM EST...995 MB COASTAL LOW HAS MOVED OVER THE DELMARVA
PENINSULA AND IS TRACKING TOWARD LONG ISLAND AS THE PRIMARY LOW TO
THE WEST REMAINS OVER NORTH CENTRAL OHIO. TEMPERATURES HAVE COOLED
ACROSS MOST OF THE CENTRAL PORTION OF THE FA DURING THE LAST FEW
HOURS AS DEWPOINTS HAVE RISEN. FAR NORTHERN PORTIONS OF THE FA
HAVE SEEN TEMPS AND DEWPOINTS RISE WITH FAR SOUTHEAST PORTION OF
FA NOT ABLE TO TAP ENOUGH COLD AIR TO SUPPORT MUCH IN THE WAY OF
MIXED PCPN WITH MOSTLY RAIN OCCURRING. PARTIAL THICKNESS
VALUES...MODEL SOUNDINGS AND HRRR TEMPS ALL SUPPORT A GRADUAL
TRANSITION DURING THE MORNING TO ALL RAIN EXCEPT ACROSS THE
SOUTHERN ADIRONDACKS WHERE A WINTRY MIX WILL CONTINUE INTO THE
AFTERNOON. BEST FRONTOGENESIS IS NOW OCCURRING ACROSS THE
NORTHERN HALF OF FA AND THIS WILL SLIDE NORTH AND EAST OF THE FA
BY 12Z. ALREADY SEEING SOME BREAKS IN THE PCPN OCCURRING ACROSS
FAR SOUTHEAST PORTION OF FA AND EXPECT THAT THIS WILL CAUSE PCPN
TO DIMINISH IN INTENSITY FROM SOUTH TO NORTH OVER THE NEXT SEVERAL
HOURS...ALTHOUGH ONE MORE ROUND OF FAIRLY INTENSE PCPN IS
EXPECTED ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS LATER THIS
MORNING. HAVE ADJUSTED POPS TO REFLECT RADAR TRENDS...PTYPE
ADJUSTED BY PARTIAL THICKNESS VALUES GOING CLOSER TO MAV WITH
FORECAST ESSENTIALLY BACK TO THAT WHICH WAS ISSUED AT 4 AM
YESTERDAY. SNOW AMOUNTS WERE GENERALLY CREATED USING A SNOW TO
LIQUID RATIO OF 6:1. HIGHEST SNOWFALL ACCUMULATIONS WILL BE IN THE
MOUNTAINS WHERE 2 TO 6 INCHES OF SNOW IS EXPECTED...HIGHEST TOTALS
OVER SOUTHERN GREEN MOUNTAINS WITH GENERALLY AN INCH OR TWO IN THE
VALLEYS. ICE ACCRETION WILL GENERALLY BE AN INCH OR LESS EXCEPT UP
TO A QUARTER OF AN INCH IS POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS.
EXPECT TEMPS TO SLOWLY RISE FROM CURRENT VALUES IN THE MID TO
UPPER 20S NORTH AND LOW TO MID 30S SOUTH TO THE LOW TO MID 30S
NORTH AND UPPER 30S TO MID 40S SOUTH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
PSEUDO WARM FRONT LIFTS NORTHWARD THURSDAY EVENING AS MID LEVEL DRY
SLOT ADVANCES NORTHWARD ACROSS THE REGION. BUFR PROFILES DO SUGGEST
AMPLE LOW LEVEL MOISTURE WHICH WILL BE CLOSE TO THE -10C ALOFT FOR
ENOUGH ICE NUCLEI TO WARRANT THE LOW CHANCE POPS FOR THE REGION
OVERNIGHT. MAIN DYNAMICS WITH OHIO VALLEY SYSTEM BEGINS TO ENCROACH
OUR WESTERN ZONES WELL AFTER MIDNIGHT WHERE WE WILL INCREASE POPS.
THERMAL PROFILES WILL REMAIN A CHALLENGE...ESPECIALLY FOR PORTIONS
OF THE MOHAWK VALLEY AND DACKS WHERE SURFACE TEMPERATURES ARE
EXPECTED TO DROP BACK INTO THE UPPER 20S AND LOWER 30S. THIS POSES
A PROBLEM WITH THE CHANCE FOR FREEZING RAIN/DRIZZLE DUE TO THE
AFOREMENTIONED POTENTIAL LACK OF ICE NUCLEI.
POTENT MID LEVEL JET COINCIDING WITH IMPRESSIVE FRONTOGENESIS WILL
MAKE FOR AN INTERESTING WEATHER ON FRIDAY MORNING. QG DIAGNOSTIC
FIELDS ARE IMPRESSIVE WITH RAPIDLY INCREASING VERTICAL VELOCITIES
OVER THE CWA AND STEEPENING MID LEVEL LAPSE RATES. WOULD NOT BE
SURPRISED TO FIND A FEW SQUALLS EMBEDDED ALONG THE ARCTIC COLD FRONT
THAT WILL MOVE EAST OF THE CWA BY LATE MORNING FRIDAY /AS SUGGESTED
IN THE EXPERIENTIAL HIRES WINDOWS OF MESOSCALE MODELS/. IN
FACT...TEMPERATURES IN THE WAKE OF THE FROPA SHOULD DROP BACK BELOW
FREEZING WHICH COULD RESULT IN BLACK ICE FORMATION WHERE SURFACES
ARE NOT TREATED. LINGERING SURFACE TROUGH AXIS AND DEFORMATION
DYNAMICS OVER WESTERN AND EASTERN NY COULD PROLONG THE SNOWFALL
WHICH WILL BE MONITORED CLOSELY. FURTHERMORE...LAKE ONTARIO
CONTRIBUTION IS EXPECTED TO INCREASE FRIDAY AFTERNOON INTO FRIDAY
NIGHT WITH A 270-280 WIND DIRECTION AND INCREASING LAKE DELTA T/S.
SEVERAL INCHES OF SNOW /AND BLOWING SNOW/ ARE POSSIBLE FOR PORTIONS
OF THE MOHAWK VALLEY...SOUTHERN DACKS. DUE TO FORECAST CHALLENGES
THAT REMAIN WITH RESPECT TO THE WIND TRAJECTORIES AND THE TIMING OF
THE INVERSION LEVELS DROPPING BELOW 5K FEET...WE WILL NOT HOIST ANY
HEADLINES AT THE PRESENT TIME. WE WILL HIGHLIGHT IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVER THE WEEKEND...THE NORTHEAST WILL BE DOMINATED BY A LARGE SCALE
TROUGH. THIS WILL KEEP TEMPS A LITTLE COOLER THAN THEY HAVE BEEN
RECENTLY AND SOMEWHAT BELOW NORMAL. HOWEVER...IT WON/T BE BRUTALLY
COLD BY ANY STRETCH. THE 12 UTC GEFS IS SHOWING 850 HPA TEMPS
GENERALLY NEAR NORMAL...WITH A BRIEF PERIOD OF ABOUT 1-2 STD BELOW
NORMAL. THE LATEST DETERMINISTIC 12 UTC GFS IS SHOWING 850 HPA
TEMPS OF AROUND -15 DEGREES C FOR SATURDAY...AND -16 TO -18 DEGREES
ON SUNDAY. THIS WILL TRANSLATE TO MAX TEMPS IN THE 20S TO LOW 30S ON
SATURDAY...AND MAX TEMPS IN THE TEENS TO LOW 20S FOR SUNDAY. MIN
TEMPS ON SAT AND SUN NIGHTS WILL GENERALLY BE IN THE SINGLE
DIGITS...WITH BELOW ZERO READINGS ACROSS THE HIGH TERRAIN. WHILE
THIS WILL PROBABLY WIND UP BEING SOME OF THE COLDER NIGHTS OF THE
SEASON SO FAR...IT/S STILL NOT FAR FROM WHAT IS CONSIDERED NORMAL OR
EXPECTED FOR THIS TIME OF THE YEAR.
IT WILL REMAIN FAIRLY DRY OVER THE WEEKEND. THE CYCLONIC FLOW MAY
ALLOW FOR SOME CLOUDS...ESP IN AREAS DOWNWIND OF LAKE ONTARIO.
HOWEVER...THE FLOW WON/T BE OVERLY CONDUCIVE FOR LAKE EFFECT...AND
INVERSION HEIGHTS OF ONLY AROUND 1 KM WILL KEEP ANY LAKE EFFECT SNOW
SHOWERS AS FAIRLY LIGHT AND CONFINED CLOSE TO THE LAKE SHORE. WILL
ONLY ALLOW A BRIEF PERIOD CHC POPS FOR PARTS OF THE MOHAWK
VALLEY/SCHOHARIE COUNTY FOR SAT MORNING...BEFORE LOWERING POPS TO
SLIGHT CHC FOR THE REMAINDER OF SATURDAY.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR MONDAY. THIS WILL
CONTINUE THE DRY WEATHER. TEMPS WILL CONTINUE TO BE A LITTLE ON THE
COOL SIDE...BUT NOTHING UNHEARD OF FOR MID JANUARY...WITH 20S FOR
MOST AREAS. SOME CLOUDS WILL BEGIN TO INCREASE FOR MONDAY NIGHT
AHEAD OF AN APPROACHING STORM SYSTEM. MIN TEMPS MAY ACTUALLY WIND
UP BEING EARLIER IN THE NIGHT...AS TEMPS MAY SLOWLY RISE OVERNIGHT
WITH AN INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW. FOR NOW...HAVE
GONE WITH MIN TEMPS IN THE TEENS IN MOST AREAS.
A STRENGTHENING LOW PRESSURE AREA WILL RACE FROM THE UPPER GREAT
LAKES TOWARDS NORTHERN QUEBEC ON TUESDAY. AN ARCTIC FRONT ASSOCIATED
WITH THIS STORM SYSTEM WILL SWING THROUGH OUR AREA ON TUESDAY. THIS
WILL ALLOW FOR SOME RAIN/SNOW SHOWERS...WITH P-TYPE DEPENDENT ON
ELEVATION/BOUNDARY LAYER TEMPS. MOST VALLEY AREAS WILL PROBABLY WARM
UP JUST ENOUGH TO KEEP MOST OF THE PRECIP AS RAIN...ESP CONSIDERING
THIS STORM IS COMING FROM THE WEST WITH A STORM SYSTEM TRACKING WELL
NORTH OF THE AREA. TEMPS LOOK TO REACH THE 30S IN VALLEY
AREAS...WITH MAX TEMPS IN THE UPPER 20S TO NEAR FREEZING IN THE HIGH
TERRAIN. PRECIP WILL BE SHOWERY IN NATURE AND QPF WILL BE RATHER
LIGHT...WITH LESS THAN A QUARTER OF AN INCH IN MOST AREAS.
IN THE WAKE OF THIS SYSTEM...COOLER AIR WILL AGAIN FILTER INTO THE
REGION FOR TUESDAY NIGHT INTO WEDNESDAY. SOME LAKE EFFECT COULD
AFFECT FAR WESTERN AREAS. TEMPS LOOK TO GO BACK BELOW NORMAL FOR
WEDNESDAY...WITH MAINLY TEENS AND 20S FOR MAX TEMPS.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
AS OF 800 AM...THE HEAVIEST PRECIPITATION HAS MOVED NORTH OF THE
TERMINALS. HOWEVER...THERE ARE MORE SHOWERS OF MAINLY RAIN WORKING
TOWARD KPOU.
REMOVED LLWS FROM KPOU SINCE THEY ARE REPORTING WIND GUSTS TO NEAR
20KTS AND THE ALY RAOB INDICATED THE WIND AT 2000 FEET AROUND 35KT
(NOT 45KTS). NARROWED THE TIME OF LLWS FROM MID TO LATER MORNING AT
KALB AND KGFL AS THAT IS WHEN THE STRONGEST WIND ALOFT MOVE THROUGH.
ALSO REMOVED ANY MENTION OF FREEZING RAIN FROM KGFL.
IFR/MVFR STRADDLE AT BOTH KALB AND KGFL BUT AS PCPN CHANGES TO RAIN
MVFR CONDITIONS WILL PREVAIL. WILL KEEP CIGS PREVAILING AT 2000 FEET
OR LESS ALTHOUGH WITH A DOWNSLOPING WIND...EVEN THESE MIGHT
OCCASIONALLY RISE UP TO VFR AS THEY DID AT KALB JUST BEFORE 800 AM.
OUR INCOMING 12Z RAOB STILL INDICATED A PRETTY STRONG ESE WIND OFF
THE DECK AT AROUND 1500 FEET. HOWEVER...IT MIGHT BE QUITE A STRONG
AS FORECASTED BY THE MODELS. WE WILL REVIEW THE LOW LEVEL WIND SHEAR
ASPECT WHEN THE ENTIRE RAOB COMES THROUGH. FOR NOW...CONTINUE WITH
LOW LEVEL WIND SHEAR UP TO 2000 FEET WITH AN E OR ESE WIND AROUND
40/45KTS THROUGH MUCH OF THE MORNING.
EVEN AFTER THE SYSTEM PASSED BY LATER TODAY...WE SHOULD HOLD ONTO
MVFR CLOUDS THROUGH MUCH OF THE NIGHT. AS LONG THAT HAPPENS...ANY
IFR FOG SHOULD BE LIMITED. HOWEVER...CONFIDENCE IN THIS THINKING IS
ONLY MODERATE...SO THIS PORTION OF THE TAF COULD CHANGE WITH
TIME.
ANOTHER UPPER LEVEL DISTURBANCE AND COLD FRONT WILL LIKELY BRING
ANOTHER ROUND OF RAIN SHOWERS ON FRIDAY...SWITCHING TO SNOW SHOWERS
AS THE DAY WEARS ON. THE WIND WILL PICK UP FROM THE WEST AND THERE
COULD EVEN BE SOME MORE INTENSE SNOW SQUALLS.
OUTLOOK...
FRI-FRI NT...MVFR/IFR...RAIN OR MIXED PRECIPITATION ENDING AS
SNOW. BECOMING WINDY.
SAT-MON...VFR...NO SIG WX.
&&
.HYDROLOGY...
A COMPLEX STORM SYSTEM CURRENTLY IMPACTING THE FA WILL CONTINUE TO
BRING MIX PRECIPITATION TO THE HYDROLOGIC SERVICE AREA THIS MORNING
TRANSITIONING TO ALL RAIN...ESPECIALLY SOUTH AND EAST OF THE SOUTHERN
ADIRONDACKS BY THE AFTERNOON. THE PRECIPITATION WILL BE ASSOCIATED
WITH A COASTAL OR SECONDARY LOW THAT WILL MOVE NORTHEAST OF LONG
ISLAND BY THIS AFTERNOON. THE PRIMARY LOW WILL REMAIN TO THE WEST
OVER THE OHIO VALLEY AND THE GREAT LAKES REGION. TOTAL LIQUID
EQUIVALENT VALUES WILL RANGE FROM A HALF AN INCH TO AROUND AN INCH
BY THURSDAY EVENING. WE ARE EXPECTING SOME DOWNSLOPING TO REDUCE
TOTAL QPF AMOUNTS TO AROUND A HALF AN INCH TO TWO THIRDS OF AN INCH
IN THE UPPER HUDSON VALLEY...AND PORTIONS OF THE LAKE GEORGE REGION.
THE HEAVIEST QPF WILL TEND TO BE SOUTH AND WEST OF THE CAPITAL
REGION. WE ARE EXPECTING MINIMAL IMPACT ON THE MAIN STEM RIVERS WITH
SOME MINOR RISES AT BEST. MOST OF THE PRECIPITATION WILL FALL AS
SNOW...SLEET AND FREEZING RAIN OVER THE NORTHERN BASINS.
TONIGHT...A BRIEF LULL WILL OCCUR BETWEEN THE SYSTEMS...WITH A
DRY SLOT. THERE MIGHT BE SOME SPOTTY FREEZING RAIN OR DRIZZLE
NORTH AND WEST OF THE CAPITAL REGION WITH SPOTTY PLAIN RAIN SOUTH
AND EAST. THE NEXT STRONG UPPER LEVEL DISTURBANCE WILL BRING RAIN
AND SNOW SHOWERS ON FRIDAY....AS IT MOVES OVER UPSTATE NY. THERE
COULD EVEN BE A FEW INTENSE SNOW SQUALLS. TOTAL QPF FROM THIS
SYSTEM LOOKS LIKE TWO TENTHS OF AN INCH SOUTHEAST TO TWO THIRDS OF
AN INCH NORTHWEST. COLDER AIR AND LAKE EFFECT SNOW SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR CTZ001.
NY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ038>041-
043-047>054-058-061-063-082>084.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ032-
033-042.
MA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
WIND ADVISORY UNTIL NOON EST TODAY FOR MAZ001.
VT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
WIND ADVISORY UNTIL NOON EST TODAY FOR VTZ013-014.
&&
$$
SYNOPSIS...11/NAS
NEAR TERM...11
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
657 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX STORM SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION
TO EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY. THE
PRECIPITATION WILL TRANSITION TO RAINFALL DURING THIS MORNING FROM
THE CAPITAL REGION AND THE MOHAWK VALLEY SOUTH AND EAST...AS A
COASTAL LOW QUICKLY MOVES NORTHEAST OF LONG ISLAND. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE OHIO VALLEY TONIGHT
INTO FRIDAY WITH MAINLY RAIN AND SNOW SHOWERS SOUTH AND MIXED
PRECIPITATION TRANSITIONING TO SNOW NORTH...AS WELL AS BLUSTERY
AND COLD CONDITIONS TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 7 AM EST...995 MB COASTAL LOW WAS LOCATED NEAR CAPE MAY WITH
THE PRIMARY LOW BACK ACROSS NORTHERN OHIO. BULK OF PCPN WITH THE
MAIN SURGE OF PCPN HAS TAPERED OFF FROM THE CAPITAL DISTRICT SOUTH
TEMPORARILY ALTHOUGH NEXT SURGE OF PCPN MAINLY IN THE FORM OF RAIN
ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS MOVING ACROSS
NORTHERN NEW JERSEY AND NORTHEAST PA. WILL LEAVE REMAINING
ADVISORIES IN PLACE FOR NOW AS STILL SOME MIXED PRECIPITATION
FALLING. AREAS TO THE NORTHWEST WHICH ARE STILL BELOW FREEZING
HAVE REPORTED A PROLONGED PERIOD OF SLEET AND FREEZING RAIN
ESPECIALLY ACROSS THE WESTERN MOHAWK VALLEY AND PORTIONS OF THE
WESTERN ADIRONDACKS. HAVE ADJUSTED HOURLY GRIDS TO BETTER FIT
CURRENT OBS AND RADAR TRENDS. ALSO HAVE ADJUSTED QPF...SNOW AND
ICE AMOUNTS SLIGHTLY TO REFLECT LATEST REPORTS AS WELL AS EXPECTED
ADDITIONAL AMOUNTS. BULK OF THE MIXED PCPN IS EXPECTED TO BE OVER
BY THE END OF THE MORNING COMMUTE EXCEPT ACROSS FAR NORTHERN AREAS
AND WILL KEEP ADVISORY UP THROUGH THE AFTERNOON AT THIS TIME FOR
THE SOUTHERN ADIRONDACKS.
AS OF 4 AM EST...995 MB COASTAL LOW HAS MOVED OVER THE DELMARVA
PENINSULA AND IS TRACKING TOWARD LONG ISLAND AS THE PRIMARY LOW TO
THE WEST REMAINS OVER NORTH CENTRAL OHIO. TEMPERATURES HAVE COOLED
ACROSS MOST OF THE CENTRAL PORTION OF THE FA DURING THE LAST FEW
HOURS AS DEWPOINTS HAVE RISEN. FAR NORTHERN PORTIONS OF THE FA
HAVE SEEN TEMPS AND DEWPOINTS RISE WITH FAR SOUTHEAST PORTION OF
FA NOT ABLE TO TAP ENOUGH COLD AIR TO SUPPORT MUCH IN THE WAY OF
MIXED PCPN WITH MOSTLY RAIN OCCURRING. PARTIAL THICKNESS
VALUES...MODEL SOUNDINGS AND HRRR TEMPS ALL SUPPORT A GRADUAL
TRANSITION DURING THE MORNING TO ALL RAIN EXCEPT ACROSS THE
SOUTHERN ADIRONDACKS WHERE A WINTRY MIX WILL CONTINUE INTO THE
AFTERNOON. BEST FRONTOGENESIS IS NOW OCCURRING ACROSS THE
NORTHERN HALF OF FA AND THIS WILL SLIDE NORTH AND EAST OF THE FA
BY 12Z. ALREADY SEEING SOME BREAKS IN THE PCPN OCCURRING ACROSS
FAR SOUTHEAST PORTION OF FA AND EXPECT THAT THIS WILL CAUSE PCPN
TO DIMINISH IN INTENSITY FROM SOUTH TO NORTH OVER THE NEXT SEVERAL
HOURS...ALTHOUGH ONE MORE ROUND OF FAIRLY INTENSE PCPN IS
EXPECTED ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS LATER THIS
MORNING. HAVE ADJUSTED POPS TO REFLECT RADAR TRENDS...PTYPE
ADJUSTED BY PARTIAL THICKNESS VALUES GOING CLOSER TO MAV WITH
FORECAST ESSENTIALLY BACK TO THAT WHICH WAS ISSUED AT 4 AM
YESTERDAY. SNOW AMOUNTS WERE GENERALLY CREATED USING A SNOW TO
LIQUID RATIO OF 6:1. HIGHEST SNOWFALL ACCUMULATIONS WILL BE IN THE
MOUNTAINS WHERE 2 TO 6 INCHES OF SNOW IS EXPECTED...HIGHEST TOTALS
OVER SOUTHERN GREEN MOUNTAINS WITH GENERALLY AN INCH OR TWO IN THE
VALLEYS. ICE ACCRETION WILL GENERALLY BE AN INCH OR LESS EXCEPT UP
TO A QUARTER OF AN INCH IS POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS.
EXPECT TEMPS TO SLOWLY RISE FROM CURRENT VALUES IN THE MID TO
UPPER 20S NORTH AND LOW TO MID 30S SOUTH TO THE LOW TO MID 30S
NORTH AND UPPER 30S TO MID 40S SOUTH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
PSEUDO WARM FRONT LIFTS NORTHWARD THURSDAY EVENING AS MID LEVEL DRY
SLOT ADVANCES NORTHWARD ACROSS THE REGION. BUFR PROFILES DO SUGGEST
AMPLE LOW LEVEL MOISTURE WHICH WILL BE CLOSE TO THE -10C ALOFT FOR
ENOUGH ICE NUCLEI TO WARRANT THE LOW CHANCE POPS FOR THE REGION
OVERNIGHT. MAIN DYNAMICS WITH OHIO VALLEY SYSTEM BEGINS TO ENCROACH
OUR WESTERN ZONES WELL AFTER MIDNIGHT WHERE WE WILL INCREASE POPS.
THERMAL PROFILES WILL REMAIN A CHALLENGE...ESPECIALLY FOR PORTIONS
OF THE MOHAWK VALLEY AND DACKS WHERE SURFACE TEMPERATURES ARE
EXPECTED TO DROP BACK INTO THE UPPER 20S AND LOWER 30S. THIS POSES
A PROBLEM WITH THE CHANCE FOR FREEZING RAIN/DRIZZLE DUE TO THE
AFOREMENTIONED POTENTIAL LACK OF ICE NUCLEI.
POTENT MID LEVEL JET COINCIDING WITH IMPRESSIVE FRONTOGENESIS WILL
MAKE FOR AN INTERESTING WEATHER ON FRIDAY MORNING. QG DIAGNOSTIC
FIELDS ARE IMPRESSIVE WITH RAPIDLY INCREASING VERTICAL VELOCITIES
OVER THE CWA AND STEEPENING MID LEVEL LAPSE RATES. WOULD NOT BE
SURPRISED TO FIND A FEW SQUALLS EMBEDDED ALONG THE ARCTIC COLD FRONT
THAT WILL MOVE EAST OF THE CWA BY LATE MORNING FRIDAY /AS SUGGESTED
IN THE EXPERIENTIAL HIRES WINDOWS OF MESOSCALE MODELS/. IN
FACT...TEMPERATURES IN THE WAKE OF THE FROPA SHOULD DROP BACK BELOW
FREEZING WHICH COULD RESULT IN BLACK ICE FORMATION WHERE SURFACES
ARE NOT TREATED. LINGERING SURFACE TROUGH AXIS AND DEFORMATION
DYNAMICS OVER WESTERN AND EASTERN NY COULD PROLONG THE SNOWFALL
WHICH WILL BE MONITORED CLOSELY. FURTHERMORE...LAKE ONTARIO
CONTRIBUTION IS EXPECTED TO INCREASE FRIDAY AFTERNOON INTO FRIDAY
NIGHT WITH A 270-280 WIND DIRECTION AND INCREASING LAKE DELTA T/S.
SEVERAL INCHES OF SNOW /AND BLOWING SNOW/ ARE POSSIBLE FOR PORTIONS
OF THE MOHAWK VALLEY...SOUTHERN DACKS. DUE TO FORECAST CHALLENGES
THAT REMAIN WITH RESPECT TO THE WIND TRAJECTORIES AND THE TIMING OF
THE INVERSION LEVELS DROPPING BELOW 5K FEET...WE WILL NOT HOIST ANY
HEADLINES AT THE PRESENT TIME. WE WILL HIGHLIGHT IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVER THE WEEKEND...THE NORTHEAST WILL BE DOMINATED BY A LARGE SCALE
TROUGH. THIS WILL KEEP TEMPS A LITTLE COOLER THAN THEY HAVE BEEN
RECENTLY AND SOMEWHAT BELOW NORMAL. HOWEVER...IT WON/T BE BRUTALLY
COLD BY ANY STRETCH. THE 12 UTC GEFS IS SHOWING 850 HPA TEMPS
GENERALLY NEAR NORMAL...WITH A BRIEF PERIOD OF ABOUT 1-2 STD BELOW
NORMAL. THE LATEST DETERMINISTIC 12 UTC GFS IS SHOWING 850 HPA
TEMPS OF AROUND -15 DEGREES C FOR SATURDAY...AND -16 TO -18 DEGREES
ON SUNDAY. THIS WILL TRANSLATE TO MAX TEMPS IN THE 20S TO LOW 30S ON
SATURDAY...AND MAX TEMPS IN THE TEENS TO LOW 20S FOR SUNDAY. MIN
TEMPS ON SAT AND SUN NIGHTS WILL GENERALLY BE IN THE SINGLE
DIGITS...WITH BELOW ZERO READINGS ACROSS THE HIGH TERRAIN. WHILE
THIS WILL PROBABLY WIND UP BEING SOME OF THE COLDER NIGHTS OF THE
SEASON SO FAR...IT/S STILL NOT FAR FROM WHAT IS CONSIDERED NORMAL OR
EXPECTED FOR THIS TIME OF THE YEAR.
IT WILL REMAIN FAIRLY DRY OVER THE WEEKEND. THE CYCLONIC FLOW MAY
ALLOW FOR SOME CLOUDS...ESP IN AREAS DOWNWIND OF LAKE ONTARIO.
HOWEVER...THE FLOW WON/T BE OVERLY CONDUCIVE FOR LAKE EFFECT...AND
INVERSION HEIGHTS OF ONLY AROUND 1 KM WILL KEEP ANY LAKE EFFECT SNOW
SHOWERS AS FAIRLY LIGHT AND CONFINED CLOSE TO THE LAKE SHORE. WILL
ONLY ALLOW A BRIEF PERIOD CHC POPS FOR PARTS OF THE MOHAWK
VALLEY/SCHOHARIE COUNTY FOR SAT MORNING...BEFORE LOWERING POPS TO
SLIGHT CHC FOR THE REMAINDER OF SATURDAY.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR MONDAY. THIS WILL
CONTINUE THE DRY WEATHER. TEMPS WILL CONTINUE TO BE A LITTLE ON THE
COOL SIDE...BUT NOTHING UNHEARD OF FOR MID JANUARY...WITH 20S FOR
MOST AREAS. SOME CLOUDS WILL BEGIN TO INCREASE FOR MONDAY NIGHT
AHEAD OF AN APPROACHING STORM SYSTEM. MIN TEMPS MAY ACTUALLY WIND
UP BEING EARLIER IN THE NIGHT...AS TEMPS MAY SLOWLY RISE OVERNIGHT
WITH AN INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW. FOR NOW...HAVE
GONE WITH MIN TEMPS IN THE TEENS IN MOST AREAS.
A STRENGTHENING LOW PRESSURE AREA WILL RACE FROM THE UPPER GREAT
LAKES TOWARDS NORTHERN QUEBEC ON TUESDAY. AN ARCTIC FRONT ASSOCIATED
WITH THIS STORM SYSTEM WILL SWING THROUGH OUR AREA ON TUESDAY. THIS
WILL ALLOW FOR SOME RAIN/SNOW SHOWERS...WITH P-TYPE DEPENDENT ON
ELEVATION/BOUNDARY LAYER TEMPS. MOST VALLEY AREAS WILL PROBABLY WARM
UP JUST ENOUGH TO KEEP MOST OF THE PRECIP AS RAIN...ESP CONSIDERING
THIS STORM IS COMING FROM THE WEST WITH A STORM SYSTEM TRACKING WELL
NORTH OF THE AREA. TEMPS LOOK TO REACH THE 30S IN VALLEY
AREAS...WITH MAX TEMPS IN THE UPPER 20S TO NEAR FREEZING IN THE HIGH
TERRAIN. PRECIP WILL BE SHOWERY IN NATURE AND QPF WILL BE RATHER
LIGHT...WITH LESS THAN A QUARTER OF AN INCH IN MOST AREAS.
IN THE WAKE OF THIS SYSTEM...COOLER AIR WILL AGAIN FILTER INTO THE
REGION FOR TUESDAY NIGHT INTO WEDNESDAY. SOME LAKE EFFECT COULD
AFFECT FAR WESTERN AREAS. TEMPS LOOK TO GO BACK BELOW NORMAL FOR
WEDNESDAY...WITH MAINLY TEENS AND 20S FOR MAX TEMPS.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
WINTRY PRECIPITATION IMPACTING KALB AND KGFL BUT WILL SOON
TRANSITION TO RAIN. MAINLY MVFR CONDITION WITH CIGS BELOW 2000 FEET
THROUGH MUCH OF THE DAY.
ONE BATCH OF HEAVIER SNOW WAS MOVING NORTH OF ALBANY. IN ITS
WAKE...MUCH LIGHTER PRECIPITATION WHICH SHOULD BECOME MAINLY
RAIN...EXCEPT STILL MIXED WITH SNOW AND SLEET AT KALB...AND EVEN A
LITTLE FREEZING RAIN AT KGFL...THROUGH MID MORNING.
OUR INCOMING 12Z RAOB STILL INDICATED A PRETTY STRONG ESE WIND OFF
THE DECK AT AROUND 1500 FEET. HOWEVER...IT MIGHT BE QUITE A STRONG
AS FORECASTED BY THE MODELS. WE WILL REVIEW THE LOW LEVEL WIND SHEAR
ASPECT WHEN THE ENTIRE RAOB COMES THROUGH. FOR NOW...CONTINUE WITH
LOW LEVEL WIND SHEAR UP TO 2000 FEET WITH AN E OR ESE WIND AROUND
40/45KTS THROUGH MUCH OF THE MORNING.
THESE ESE FLOW WILL RESULT IN DOWNSLOPE OFF THE HIGHER TERRAIN TO
THE EAST AND AS RESULT WILL LIKELY KEEP CIGS AND VSBY (ONCE THE PCPN
TURNS TO RAIN)...ABOVE IFR...IN THE LOW MVFR RANGE. HOWEVER...CIGS
LOOK TO REMAIN AT OR BELOW 2000 FEET MUCH OF THE DAY.
EVEN AFTER THE SYSTEM PASSED BY LATER TODAY...WE SHOULD HOLD ONTO
MVFR CLOUDS THROUGH MUCH OF THE NIGHT. AS LONG THAT HAPPENS...ANY
IFR FOG SHOULD BE LIMITED. HOWEVER...CONFIDENCE IN THIS THINKING IS
ONLY MODERATE...SO THIS PORTION OF THE TAF COULD CHANGE WITH
TIME.
ANOTHER UPPER LEVEL DISTURBANCE AND COLD FRONT WILL LIKELY BRING
ANOTHER ROUND OF RAIN SHOWERS ON FRIDAY...SWITCHING TO SNOW SHOWERS
AS THE DAY WEARS ON. THE WIND WILL PICK UP FROM THE WEST AND THERE
COULD EVEN BE SOME MORE INTENSE SNOW SQUALLS.
OUTLOOK...
FRI-FRI NT...MVFR/IFR...RAIN OR MIXED PRECIPITATION ENDING AS
SNOW. BECOMING WINDY.
SAT-MON...VFR...NO SIG WX.
HWJIV
OUTLOOK...
THU NT-FRI NT...MVFR/IFR...RAIN OR MIXED PRECIPITATION ENDING AS
SNOW. BCMG WINDY FRI.
SAT-MON...VFR...NO SIG WX.
&&
.HYDROLOGY...
A COMPLEX STORM SYSTEM CURRENTLY IMPACTING THE FA WILL CONTINUE TO
BRING MIX PRECIPITATION TO THE HYDROLOGIC SERVICE AREA THIS MORNING
TRANSITIONING TO ALL RAIN...ESPECIALLY SOUTH AND EAST OF THE SOUTHERN
ADIRONDACKS BY THE AFTERNOON. THE PRECIPITATION WILL BE ASSOCIATED
WITH A COASTAL OR SECONDARY LOW THAT WILL MOVE NORTHEAST OF LONG
ISLAND BY THIS AFTERNOON. THE PRIMARY LOW WILL REMAIN TO THE WEST
OVER THE OHIO VALLEY AND THE GREAT LAKES REGION. TOTAL LIQUID
EQUIVALENT VALUES WILL RANGE FROM A HALF AN INCH TO AROUND AN INCH
BY THURSDAY EVENING. WE ARE EXPECTING SOME DOWNSLOPING TO REDUCE
TOTAL QPF AMOUNTS TO AROUND A HALF AN INCH TO TWO THIRDS OF AN INCH
IN THE UPPER HUDSON VALLEY...AND PORTIONS OF THE LAKE GEORGE REGION.
THE HEAVIEST QPF WILL TEND TO BE SOUTH AND WEST OF THE CAPITAL
REGION. WE ARE EXPECTING MINIMAL IMPACT ON THE MAIN STEM RIVERS WITH
SOME MINOR RISES AT BEST. MOST OF THE PRECIPITATION WILL FALL AS
SNOW...SLEET AND FREEZING RAIN OVER THE NORTHERN BASINS.
TONIGHT...A BRIEF LULL WILL OCCUR BETWEEN THE SYSTEMS...WITH A
DRY SLOT. THERE MIGHT BE SOME SPOTTY FREEZING RAIN OR DRIZZLE
NORTH AND WEST OF THE CAPITAL REGION WITH SPOTTY PLAIN RAIN SOUTH
AND EAST. THE NEXT STRONG UPPER LEVEL DISTURBANCE WILL BRING RAIN
AND SNOW SHOWERS ON FRIDAY....AS IT MOVES OVER UPSTATE NY. THERE
COULD EVEN BE A FEW INTENSE SNOW SQUALLS. TOTAL QPF FROM THIS
SYSTEM LOOKS LIKE TWO TENTHS OF AN INCH SOUTHEAST TO TWO THIRDS OF
AN INCH NORTHWEST. COLDER AIR AND LAKE EFFECT SNOW SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR CTZ001.
NY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ038>041-
043-047>054-058-061-063-082>084.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ032-
033-042.
MA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
WIND ADVISORY UNTIL NOON EST TODAY FOR MAZ001.
VT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
WIND ADVISORY UNTIL NOON EST TODAY FOR VTZ013-014.
&&
$$
SYNOPSIS...11/NAS
NEAR TERM...11
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
HYDROLOGY...11
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ALBANY NY
512 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX STORM SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION
TO EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY. THE
PRECIPITATION WILL TRANSITION TO RAINFALL DURING THIS MORNING FROM
THE CAPITAL REGION AND THE MOHAWK VALLEY SOUTH AND EAST...AS A
COASTAL LOW QUICKLY MOVES NORTHEAST OF LONG ISLAND. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE OHIO VALLEY TONIGHT
INTO FRIDAY WITH MAINLY RAIN AND SNOW SHOWERS SOUTH AND MIXED
PRECIPITATION TRANSITIONING TO SNOW NORTH...AS WELL AS BLUSTERY
AND COLD CONDITIONS TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 4 AM EST...995 MB COASTAL LOW HAS MOVED OVER THE DELMARVA
PENINSULA AND IS TRACKING TOWARD LONG ISLAND AS THE PRIMARY LOW TO
THE WEST REMAINS OVER NORTH CENTRAL OHIO. TEMPERATURES HAVE COOLED
ACROSS MOST OF THE CENTRAL PORTION OF THE FA DURING THE LAST FEW
HOURS AS DEWPOINTS HAVE RISEN. FAR NORTHERN PORTIONS OF THE FA
HAVE SEEN TEMPS AND DEWPOINTS RISE WITH FAR SOUTHEAST PORTION OF
FA NOT ABLE TO TAP ENOUGH COLD AIR TO SUPPORT MUCH IN THE WAY OF
MIXED PCPN WITH MOSTLY RAIN OCCURRING. PARTIAL THICKNESS
VALUES...MODEL SOUNDINGS AND HRRR TEMPS ALL SUPPORT A GRADUAL
TRANSITION DURING THE MORNING TO ALL RAIN EXCEPT ACROSS THE
SOUTHERN ADIRONDACKS WHERE A WINTRY MIX WILL CONTINUE INTO THE
AFTERNOON. BEST FRONTOGENESIS IS NOW OCCURRING ACROSS THE
NORTHERN HALF OF FA AND THIS WILL SLIDE NORTH AND EAST OF THE FA
BY 12Z. ALREADY SEEING SOME BREAKS IN THE PCPN OCCURRING ACROSS
FAR SOUTHEAST PORTION OF FA AND EXPECT THAT THIS WILL CAUSE PCPN
TO DIMINISH IN INTENSITY FROM SOUTH TO NORTH OVER THE NEXT SEVERAL
HOURS...ALTHOUGH ONE MORE ROUND OF FAIRLY INTENSE PCPN IS
EXPECTED ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS LATER THIS
MORNING. HAVE ADJUSTED POPS TO REFLECT RADAR TRENDS...PTYPE
ADJUSTED BY PARTIAL THICKNESS VALUES GOING CLOSER TO MAV WITH
FORECAST ESSENTIALLY BACK TO THAT WHICH WAS ISSUED AT 4 AM
YESTERDAY. SNOW AMOUNTS WERE GENERALLY CREATED USING A SNOW TO
LIQUID RATIO OF 6:1. HIGHEST SNOWFALL ACCUMULATIONS WILL BE IN THE
MOUNTAINS WHERE 2 TO 6 INCHES OF SNOW IS EXPECTED...HIGHEST TOTALS
OVER SOUTHERN GREEN MOUNTAINS WITH GENERALLY AN INCH OR TWO IN THE
VALLEYS. ICE ACCRETION WILL GENERALLY BE AN INCH OR LESS EXCEPT UP
TO A QUARTER OF AN INCH IS POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS.
EXPECT TEMPS TO SLOWLY RISE FROM CURRENT VALUES IN THE MID TO
UPPER 20S NORTH AND LOW TO MID 30S SOUTH TO THE LOW TO MID 30S
NORTH AND UPPER 30S TO MID 40S SOUTH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
PSEUDO WARM FRONT LIFTS NORTHWARD THURSDAY EVENING AS MID LEVEL DRY
SLOT ADVANCES NORTHWARD ACROSS THE REGION. BUFR PROFILES DO SUGGEST
AMPLE LOW LEVEL MOISTURE WHICH WILL BE CLOSE TO THE -10C ALOFT FOR
ENOUGH ICE NUCLEI TO WARRANT THE LOW CHANCE POPS FOR THE REGION
OVERNIGHT. MAIN DYNAMICS WITH OHIO VALLEY SYSTEM BEGINS TO ENCROACH
OUR WESTERN ZONES WELL AFTER MIDNIGHT WHERE WE WILL INCREASE POPS.
THERMAL PROFILES WILL REMAIN A CHALLENGE...ESPECIALLY FOR PORTIONS
OF THE MOHAWK VALLEY AND DACKS WHERE SURFACE TEMPERATURES ARE
EXPECTED TO DROP BACK INTO THE UPPER 20S AND LOWER 30S. THIS POSES
A PROBLEM WITH THE CHANCE FOR FREEZING RAIN/DRIZZLE DUE TO THE
AFOREMENTIONED POTENTIAL LACK OF ICE NUCLEI.
POTENT MID LEVEL JET COINCIDING WITH IMPRESSIVE FRONTOGENESIS WILL
MAKE FOR AN INTERESTING WEATHER ON FRIDAY MORNING. QG DIAGNOSTIC
FIELDS ARE IMPRESSIVE WITH RAPIDLY INCREASING VERTICAL VELOCITIES
OVER THE CWA AND STEEPENING MID LEVEL LAPSE RATES. WOULD NOT BE
SURPRISED TO FIND A FEW SQUALLS EMBEDDED ALONG THE ARCTIC COLD FRONT
THAT WILL MOVE EAST OF THE CWA BY LATE MORNING FRIDAY /AS SUGGESTED
IN THE EXPERIENTIAL HIRES WINDOWS OF MESOSCALE MODELS/. IN
FACT...TEMPERATURES IN THE WAKE OF THE FROPA SHOULD DROP BACK BELOW
FREEZING WHICH COULD RESULT IN BLACK ICE FORMATION WHERE SURFACES
ARE NOT TREATED. LINGERING SURFACE TROUGH AXIS AND DEFORMATION
DYNAMICS OVER WESTERN AND EASTERN NY COULD PROLONG THE SNOWFALL
WHICH WILL BE MONITORED CLOSELY. FURTHERMORE...LAKE ONTARIO
CONTRIBUTION IS EXPECTED TO INCREASE FRIDAY AFTERNOON INTO FRIDAY
NIGHT WITH A 270-280 WIND DIRECTION AND INCREASING LAKE DELTA T/S.
SEVERAL INCHES OF SNOW /AND BLOWING SNOW/ ARE POSSIBLE FOR PORTIONS
OF THE MOHAWK VALLEY...SOUTHERN DACKS. DUE TO FORECAST CHALLENGES
THAT REMAIN WITH RESPECT TO THE WIND TRAJECTORIES AND THE TIMING OF
THE INVERSION LEVELS DROPPING BELOW 5K FEET...WE WILL NOT HOIST ANY
HEADLINES AT THE PRESENT TIME. WE WILL HIGHLIGHT IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVER THE WEEKEND...THE NORTHEAST WILL BE DOMINATED BY A LARGE SCALE
TROUGH. THIS WILL KEEP TEMPS A LITTLE COOLER THAN THEY HAVE BEEN
RECENTLY AND SOMEWHAT BELOW NORMAL. HOWEVER...IT WON/T BE BRUTALLY
COLD BY ANY STRETCH. THE 12 UTC GEFS IS SHOWING 850 HPA TEMPS
GENERALLY NEAR NORMAL...WITH A BRIEF PERIOD OF ABOUT 1-2 STD BELOW
NORMAL. THE LATEST DETERMINISTIC 12 UTC GFS IS SHOWING 850 HPA
TEMPS OF AROUND -15 DEGREES C FOR SATURDAY...AND -16 TO -18 DEGREES
ON SUNDAY. THIS WILL TRANSLATE TO MAX TEMPS IN THE 20S TO LOW 30S ON
SATURDAY...AND MAX TEMPS IN THE TEENS TO LOW 20S FOR SUNDAY. MIN
TEMPS ON SAT AND SUN NIGHTS WILL GENERALLY BE IN THE SINGLE
DIGITS...WITH BELOW ZERO READINGS ACROSS THE HIGH TERRAIN. WHILE
THIS WILL PROBABLY WIND UP BEING SOME OF THE COLDER NIGHTS OF THE
SEASON SO FAR...IT/S STILL NOT FAR FROM WHAT IS CONSIDERED NORMAL OR
EXPECTED FOR THIS TIME OF THE YEAR.
IT WILL REMAIN FAIRLY DRY OVER THE WEEKEND. THE CYCLONIC FLOW MAY
ALLOW FOR SOME CLOUDS...ESP IN AREAS DOWNWIND OF LAKE ONTARIO.
HOWEVER...THE FLOW WON/T BE OVERLY CONDUCIVE FOR LAKE EFFECT...AND
INVERSION HEIGHTS OF ONLY AROUND 1 KM WILL KEEP ANY LAKE EFFECT SNOW
SHOWERS AS FAIRLY LIGHT AND CONFINED CLOSE TO THE LAKE SHORE. WILL
ONLY ALLOW A BRIEF PERIOD CHC POPS FOR PARTS OF THE MOHAWK
VALLEY/SCHOHARIE COUNTY FOR SAT MORNING...BEFORE LOWERING POPS TO
SLIGHT CHC FOR THE REMAINDER OF SATURDAY.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR MONDAY. THIS WILL
CONTINUE THE DRY WEATHER. TEMPS WILL CONTINUE TO BE A LITTLE ON THE
COOL SIDE...BUT NOTHING UNHEARD OF FOR MID JANUARY...WITH 20S FOR
MOST AREAS. SOME CLOUDS WILL BEGIN TO INCREASE FOR MONDAY NIGHT
AHEAD OF AN APPROACHING STORM SYSTEM. MIN TEMPS MAY ACTUALLY WIND
UP BEING EARLIER IN THE NIGHT...AS TEMPS MAY SLOWLY RISE OVERNIGHT
WITH AN INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW. FOR NOW...HAVE
GONE WITH MIN TEMPS IN THE TEENS IN MOST AREAS.
A STRENGTHENING LOW PRESSURE AREA WILL RACE FROM THE UPPER GREAT
LAKES TOWARDS NORTHERN QUEBEC ON TUESDAY. AN ARCTIC FRONT ASSOCIATED
WITH THIS STORM SYSTEM WILL SWING THROUGH OUR AREA ON TUESDAY. THIS
WILL ALLOW FOR SOME RAIN/SNOW SHOWERS...WITH P-TYPE DEPENDENT ON
ELEVATION/BOUNDARY LAYER TEMPS. MOST VALLEY AREAS WILL PROBABLY WARM
UP JUST ENOUGH TO KEEP MOST OF THE PRECIP AS RAIN...ESP CONSIDERING
THIS STORM IS COMING FROM THE WEST WITH A STORM SYSTEM TRACKING WELL
NORTH OF THE AREA. TEMPS LOOK TO REACH THE 30S IN VALLEY
AREAS...WITH MAX TEMPS IN THE UPPER 20S TO NEAR FREEZING IN THE HIGH
TERRAIN. PRECIP WILL BE SHOWERY IN NATURE AND QPF WILL BE RATHER
LIGHT...WITH LESS THAN A QUARTER OF AN INCH IN MOST AREAS.
IN THE WAKE OF THIS SYSTEM...COOLER AIR WILL AGAIN FILTER INTO THE
REGION FOR TUESDAY NIGHT INTO WEDNESDAY. SOME LAKE EFFECT COULD
AFFECT FAR WESTERN AREAS. TEMPS LOOK TO GO BACK BELOW NORMAL FOR
WEDNESDAY...WITH MAINLY TEENS AND 20S FOR MAX TEMPS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
AS OF 515 AM...SNOW HAS REACHED KGFL AND CONTINUED AT KALB. RAIN
FALLING AT KPOU.
WARMER AIR ALOFT....AND LIGHTER PCPN AMOUNTS WILL ALLOW THE PCPN TO
MIX WITH SLEET AND RAIN AND EVENTUALLY CHANGE TO ALL RAIN LATER THIS
MORNING. IFR CONDITIONS WILL LIKELY TRANSITION TO MVFR LATER THIS
MORNING SINCE THE PCPN GOES TO RAIN AND WE ARE LOOKING AT AN
EASTERLY DOWNSLOPE COMPONENT AT ALL TAF SITES.
DUE TO THE STRENGTH OF THIS SYSTEM...LLWS DOES SEEM TO BE INCREASING
AND EVIDENCE IS SHOWING UP IN THE VWP. SO WE WILL INCLUDE LLWS FOR
ALL TAF SITES OVERNIGHT AND TOWARD SUNRISE THURSDAY.
PRECIP WILL BEGIN TO TAPER OFF AS WE DRY SLOT THROUGH THE DAY
THURSDAY.
OUTLOOK...
THU NT-FRI NT...MVFR/IFR...RAIN OR MIXED PRECIPITATION ENDING AS
SNOW. BECMG WINDY FRI.
SAT-MON...VFR...NO SIG WX.
&&
.HYDROLOGY...
A COMPLEX STORM SYSTEM CURRENTLY IMPACTING THE FA WILL CONTINUE TO
BRING MIX PRECIPITATION TO THE HYDROLOGIC SERVICE AREA THIS MORNING
TRANSITIONING TO ALL RAIN...ESPECIALLY SOUTH AND EAST OF THE SOUTHERN
ADIRONDACKS BY THE AFTERNOON. THE PRECIPITATION WILL BE ASSOCIATED
WITH A COASTAL OR SECONDARY LOW THAT WILL MOVE NORTHEAST OF LONG
ISLAND BY THIS AFTERNOON. THE PRIMARY LOW WILL REMAIN TO THE WEST
OVER THE OHIO VALLEY AND THE GREAT LAKES REGION. TOTAL LIQUID
EQUIVALENT VALUES WILL RANGE FROM A HALF AN INCH TO AROUND AN INCH
BY THURSDAY EVENING. WE ARE EXPECTING SOME DOWNSLOPING TO REDUCE
TOTAL QPF AMOUNTS TO AROUND A HALF AN INCH TO TWO THIRDS OF AN INCH
IN THE UPPER HUDSON VALLEY...AND PORTIONS OF THE LAKE GEORGE REGION.
THE HEAVIEST QPF WILL TEND TO BE SOUTH AND WEST OF THE CAPITAL
REGION. WE ARE EXPECTING MINIMAL IMPACT ON THE MAIN STEM RIVERS WITH
SOME MINOR RISES AT BEST. MOST OF THE PRECIPITATION WILL FALL AS
SNOW...SLEET AND FREEZING RAIN OVER THE NORTHERN BASINS.
TONIGHT...A BRIEF LULL WILL OCCUR BETWEEN THE SYSTEMS...WITH A
DRY SLOT. THERE MIGHT BE SOME SPOTTY FREEZING RAIN OR DRIZZLE
NORTH AND WEST OF THE CAPITAL REGION WITH SPOTTY PLAIN RAIN SOUTH
AND EAST. THE NEXT STRONG UPPER LEVEL DISTURBANCE WILL BRING RAIN
AND SNOW SHOWERS ON FRIDAY....AS IT MOVES OVER UPSTATE NY. THERE
COULD EVEN BE A FEW INTENSE SNOW SQUALLS. TOTAL QPF FROM THIS
SYSTEM LOOKS LIKE TWO TENTHS OF AN INCH SOUTHEAST TO TWO THIRDS OF
AN INCH NORTHWEST. COLDER AIR AND LAKE EFFECT SNOW SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR CTZ001.
NY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ038>041-
043-047>054-058-061-063-082>084.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ032-
033-042.
MA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
WIND ADVISORY UNTIL NOON EST TODAY FOR MAZ001.
VT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
WIND ADVISORY UNTIL NOON EST TODAY FOR VTZ013-014.
&&
$$
SYNOPSIS...11/NAS
NEAR TERM...11
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...BGM
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
506 AM EST THU JAN 12 2012
.SYNOPSIS...
A COMPLEX STORM SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION
TO EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY. THE
PRECIPITATION WILL TRANSITION TO RAINFALL DURING THIS MORNING FROM
THE CAPITAL REGION AND THE MOHAWK VALLEY SOUTH AND EAST...AS A
COASTAL LOW QUICKLY MOVES NORTHEAST OF LONG ISLAND. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE OHIO VALLEY TONIGHT
INTO FRIDAY WITH MAINLY RAIN AND SNOW SHOWERS SOUTH AND MIXED
PRECIPITATION TRANSITIONING TO SNOW NORTH...AS WELL AS BLUSTERY
AND COLD CONDITIONS TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 4 AM EST...995 MB COASTAL LOW HAS MOVED OVER THE DELMARVA
PENINSULA AND IS TRACKING TOWARD LONG ISLAND AS THE PRIMARY LOW TO
THE WEST REMAINS OVER NORTH CENTRAL OHIO. TEMPERATURES HAVE COOLED
ACROSS MOST OF THE CENTRAL PORTION OF THE FA DURING THE LAST FEW
HOURS AS DEWPOINTS HAVE RISEN. FAR NORTHERN PORTIONS OF THE FA
HAVE SEEN TEMPS AND DEWPOINTS RISE WITH FAR SOUTHEAST PORTION OF
FA NOT ABLE TO TAP ENOUGH COLD AIR TO SUPPORT MUCH IN THE WAY OF
MIXED PCPN WITH MOSTLY RAIN OCCURRING. PARTIAL THICKNESS
VALUES...MODEL SOUNDINGS AND HRRR TEMPS ALL SUPPORT A GRADUAL
TRANSITION DURING THE MORNING TO ALL RAIN EXCEPT ACROSS THE
SOUTHERN ADIRONDACKS WHERE A WINTRY MIX WILL CONTINUE INTO THE
AFTERNOON. BEST FRONTOGENESIS IS NOW OCCURRING ACROSS THE
NORTHERN HALF OF FA AND THIS WILL SLIDE NORTH AND EAST OF THE FA
BY 12Z. ALREADY SEEING SOME BREAKS IN THE PCPN OCCURRING ACROSS
FAR SOUTHEAST PORTION OF FA AND EXPECT THAT THIS WILL CAUSE PCPN
TO DIMINISH IN INTENSITY FROM SOUTH TO NORTH OVER THE NEXT SEVERAL
HOURS...ALTHOUGH ONE MORE ROUND OF FAIRLY INTENSE PCPN IS
EXPECTED ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS LATER THIS
MORNING. HAVE ADJUSTED POPS TO REFLECT RADAR TRENDS...PTYPE
ADJUSTED BY PARTIAL THICKNESS VALUES GOING CLOSER TO MAV WITH
FORECAST ESSENTIALLY BACK TO THAT WHICH WAS ISSUED AT 4 AM
YESTERDAY. SNOW AMOUNTS WERE GENERALLY CREATED USING A SNOW TO
LIQUID RATIO OF 6:1. HIGHEST SNOWFALL ACCUMULATIONS WILL BE IN THE
MOUNTAINS WHERE 2 TO 6 INCHES OF SNOW IS EXPECTED...HIGHEST TOTALS
OVER SOUTHERN GREEN MOUNTAINS WITH GENERALLY AN INCH OR TWO IN THE
VALLEYS. ICE ACCRETION WILL GENERALLY BE AN INCH OR LESS EXCEPT UP
TO A QUARTER OF AN INCH IS POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS.
EXPECT TEMPS TO SLOWLY RISE FROM CURRENT VALUES IN THE MID TO
UPPER 20S NORTH AND LOW TO MID 30S SOUTH TO THE LOW TO MID 30S
NORTH AND UPPER 30S TO MID 40S SOUTH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
PSEUDO WARM FRONT LIFTS NORTHWARD THURSDAY EVENING AS MID LEVEL DRY
SLOT ADVANCES NORTHWARD ACROSS THE REGION. BUFR PROFILES DO SUGGEST
AMPLE LOW LEVEL MOISTURE WHICH WILL BE CLOSE TO THE -10C ALOFT FOR
ENOUGH ICE NUCLEI TO WARRANT THE LOW CHANCE POPS FOR THE REGION
OVERNIGHT. MAIN DYNAMICS WITH OHIO VALLEY SYSTEM BEGINS TO ENCROACH
OUR WESTERN ZONES WELL AFTER MIDNIGHT WHERE WE WILL INCREASE POPS.
THERMAL PROFILES WILL REMAIN A CHALLENGE...ESPECIALLY FOR PORTIONS
OF THE MOHAWK VALLEY AND DACKS WHERE SURFACE TEMPERATURES ARE
EXPECTED TO DROP BACK INTO THE UPPER 20S AND LOWER 30S. THIS POSES
A PROBLEM WITH THE CHANCE FOR FREEZING RAIN/DRIZZLE DUE TO THE
AFOREMENTIONED POTENTIAL LACK OF ICE NUCLEI.
POTENT MID LEVEL JET COINCIDING WITH IMPRESSIVE FRONTOGENESIS WILL
MAKE FOR AN INTERESTING WEATHER ON FRIDAY MORNING. QG DIAGNOSTIC
FIELDS ARE IMPRESSIVE WITH RAPIDLY INCREASING VERTICAL VELOCITIES
OVER THE CWA AND STEEPENING MID LEVEL LAPSE RATES. WOULD NOT BE
SURPRISED TO FIND A FEW SQUALLS EMBEDDED ALONG THE ARCTIC COLD FRONT
THAT WILL MOVE EAST OF THE CWA BY LATE MORNING FRIDAY /AS SUGGESTED
IN THE EXPERIENTIAL HIRES WINDOWS OF MESOSCALE MODELS/. IN
FACT...TEMPERATURES IN THE WAKE OF THE FROPA SHOULD DROP BACK BELOW
FREEZING WHICH COULD RESULT IN BLACK ICE FORMATION WHERE SURFACES
ARE NOT TREATED. LINGERING SURFACE TROUGH AXIS AND DEFORMATION
DYNAMICS OVER WESTERN AND EASTERN NY COULD PROLONG THE SNOWFALL
WHICH WILL BE MONITORED CLOSELY. FURTHERMORE...LAKE ONTARIO
CONTRIBUTION IS EXPECTED TO INCREASE FRIDAY AFTERNOON INTO FRIDAY
NIGHT WITH A 270-280 WIND DIRECTION AND INCREASING LAKE DELTA T/S.
SEVERAL INCHES OF SNOW /AND BLOWING SNOW/ ARE POSSIBLE FOR PORTIONS
OF THE MOHAWK VALLEY...SOUTHERN DACKS. DUE TO FORECAST CHALLENGES
THAT REMAIN WITH RESPECT TO THE WIND TRAJECTORIES AND THE TIMING OF
THE INVERSION LEVELS DROPPING BELOW 5K FEET...WE WILL NOT HOIST ANY
HEADLINES AT THE PRESENT TIME. WE WILL HIGHLIGHT IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVER THE WEEKEND...THE NORTHEAST WILL BE DOMINATED BY A LARGE SCALE
TROUGH. THIS WILL KEEP TEMPS A LITTLE COOLER THAN THEY HAVE BEEN
RECENTLY AND SOMEWHAT BELOW NORMAL. HOWEVER...IT WON/T BE BRUTALLY
COLD BY ANY STRETCH. THE 12 UTC GEFS IS SHOWING 850 HPA TEMPS
GENERALLY NEAR NORMAL...WITH A BRIEF PERIOD OF ABOUT 1-2 STD BELOW
NORMAL. THE LATEST DETERMINISTIC 12 UTC GFS IS SHOWING 850 HPA
TEMPS OF AROUND -15 DEGREES C FOR SATURDAY...AND -16 TO -18 DEGREES
ON SUNDAY. THIS WILL TRANSLATE TO MAX TEMPS IN THE 20S TO LOW 30S ON
SATURDAY...AND MAX TEMPS IN THE TEENS TO LOW 20S FOR SUNDAY. MIN
TEMPS ON SAT AND SUN NIGHTS WILL GENERALLY BE IN THE SINGLE
DIGITS...WITH BELOW ZERO READINGS ACROSS THE HIGH TERRAIN. WHILE
THIS WILL PROBABLY WIND UP BEING SOME OF THE COLDER NIGHTS OF THE
SEASON SO FAR...IT/S STILL NOT FAR FROM WHAT IS CONSIDERED NORMAL OR
EXPECTED FOR THIS TIME OF THE YEAR.
IT WILL REMAIN FAIRLY DRY OVER THE WEEKEND. THE CYCLONIC FLOW MAY
ALLOW FOR SOME CLOUDS...ESP IN AREAS DOWNWIND OF LAKE ONTARIO.
HOWEVER...THE FLOW WON/T BE OVERLY CONDUCIVE FOR LAKE EFFECT...AND
INVERSION HEIGHTS OF ONLY AROUND 1 KM WILL KEEP ANY LAKE EFFECT SNOW
SHOWERS AS FAIRLY LIGHT AND CONFINED CLOSE TO THE LAKE SHORE. WILL
ONLY ALLOW A BRIEF PERIOD CHC POPS FOR PARTS OF THE MOHAWK
VALLEY/SCHOHARIE COUNTY FOR SAT MORNING...BEFORE LOWERING POPS TO
SLIGHT CHC FOR THE REMAINDER OF SATURDAY.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR MONDAY. THIS WILL
CONTINUE THE DRY WEATHER. TEMPS WILL CONTINUE TO BE A LITTLE ON THE
COOL SIDE...BUT NOTHING UNHEARD OF FOR MID JANUARY...WITH 20S FOR
MOST AREAS. SOME CLOUDS WILL BEGIN TO INCREASE FOR MONDAY NIGHT
AHEAD OF AN APPROACHING STORM SYSTEM. MIN TEMPS MAY ACTUALLY WIND
UP BEING EARLIER IN THE NIGHT...AS TEMPS MAY SLOWLY RISE OVERNIGHT
WITH AN INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW. FOR NOW...HAVE
GONE WITH MIN TEMPS IN THE TEENS IN MOST AREAS.
A STRENGTHENING LOW PRESSURE AREA WILL RACE FROM THE UPPER GREAT
LAKES TOWARDS NORTHERN QUEBEC ON TUESDAY. AN ARCTIC FRONT ASSOCIATED
WITH THIS STORM SYSTEM WILL SWING THROUGH OUR AREA ON TUESDAY. THIS
WILL ALLOW FOR SOME RAIN/SNOW SHOWERS...WITH P-TYPE DEPENDENT ON
ELEVATION/BOUNDARY LAYER TEMPS. MOST VALLEY AREAS WILL PROBABLY WARM
UP JUST ENOUGH TO KEEP MOST OF THE PRECIP AS RAIN...ESP CONSIDERING
THIS STORM IS COMING FROM THE WEST WITH A STORM SYSTEM TRACKING WELL
NORTH OF THE AREA. TEMPS LOOK TO REACH THE 30S IN VALLEY
AREAS...WITH MAX TEMPS IN THE UPPER 20S TO NEAR FREEZING IN THE HIGH
TERRAIN. PRECIP WILL BE SHOWERY IN NATURE AND QPF WILL BE RATHER
LIGHT...WITH LESS THAN A QUARTER OF AN INCH IN MOST AREAS.
IN THE WAKE OF THIS SYSTEM...COOLER AIR WILL AGAIN FILTER INTO THE
REGION FOR TUESDAY NIGHT INTO WEDNESDAY. SOME LAKE EFFECT COULD
AFFECT FAR WESTERN AREAS. TEMPS LOOK TO GO BACK BELOW NORMAL FOR
WEDNESDAY...WITH MAINLY TEENS AND 20S FOR MAX TEMPS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
THE ONSET OF THE PRECIP WAS ADVANCING NORTHWARD COINCIDING WITH IFR
CONDITIONS AND INTERACTING WITH A VERY COMPLEX SURFACE
TEMPERATURES. FOR KPOU...A MAINLY RAIN EVENT EXPECTED. FURTHER
NORTH...A WINTRY MIXTURE FOR KALB THROUGH THIS EARLY THURSDAY
MORNING. KGFL...MAINLY SNOW THROUGH THIS EARLY THURSDAY MORNING
WITH A TRANSITION TOWARD SOME SLEET. AS WARMER AIR ADVANCES
NORTHWARD...A PERIOD OF SLEET AND FREEZING RAIN IS EXPECTED BEFORE
CHANGING OVER TO MAINLY RAIN TOWARD THE NOON HOUR. DUE TO THE
STRENGTH OF THIS SYSTEM...LLWS DOES SEEM TO BE INCREASING AND
EVIDENCE IS SHOWING UP IN THE VWP. SO WE WILL INCLUDE LLWS FOR ALL
TAF SITES OVERNIGHT AND TOWARD SUNRISE THURSDAY.
PRECIP WILL BEGIN TO TAPER OFF AS WE DRY SLOT THROUGH THE DAY
THURSDAY.
OUTLOOK...
THU NT-FRI NT...MVFR/IFR...RAIN OR MIXED PRECIPITATION ENDING AS
SNOW. BECMG WINDY FRI.
SAT-MON...VFR...NO SIG WX.
&&
.HYDROLOGY...
A COMPLEX STORM SYSTEM CURRENTLY IMPACTING THE FA WILL CONTINUE TO BRING
MIX PRECIPITATION TO THE HYDROLOGIC SERVICE AREA THIS MORNING TRANSITIONING
TO ALL RAIN...ESPECIALLY SOUTH AND EAST OF THE SOUTHERN
ADIRONDACKS BY THE AFTERNOON. THE PRECIPITATION WILL BE ASSOCIATED
WITH A COASTAL OR SECONDARY LOW THAT WILL MOVE NORTHEAST OF LONG
ISLAND BY THIS AFTERNOON. THE PRIMARY LOW WILL REMAIN TO THE WEST
OVER THE OHIO VALLEY AND THE GREAT LAKES REGION. TOTAL LIQUID
EQUIVALENT VALUES WILL RANGE FROM A HALF AN INCH TO AROUND AN
INCH BY THURSDAY EVENING. WE ARE EXPECTING SOME DOWNSLOPING TO
REDUCE TOTAL QPF AMOUNTS TO AROUND A HALF AN INCH TO TWO THIRDS OF
AN INCH IN THE UPPER HUDSON VALLEY...AND PORTIONS OF THE LAKE
GEORGE REGION. THE HEAVIEST QPF WILL TEND TO BE SOUTH AND WEST OF
THE CAPITAL REGION. WE ARE EXPECTING MINIMAL IMPACT ON THE MAIN
STEM RIVERS WITH SOME MINOR RISES AT BEST. MOST OF THE
PRECIPITATION WILL FALL AS SNOW...SLEET AND FREEZING RAIN OVER THE
NORTHERN BASINS.
TONIGHT...A BRIEF LULL WILL OCCUR BETWEEN THE SYSTEMS...WITH A
DRY SLOT. THERE MIGHT BE SOME SPOTTY FREEZING RAIN OR DRIZZLE
NORTH AND WEST OF THE CAPITAL REGION WITH SPOTTY PLAIN RAIN SOUTH
AND EAST. THE NEXT STRONG UPPER LEVEL DISTURBANCE WILL BRING RAIN
AND SNOW SHOWERS ON FRIDAY....AS IT MOVES OVER UPSTATE NY. THERE
COULD EVEN BE A FEW INTENSE SNOW SQUALLS. TOTAL QPF FROM THIS
SYSTEM LOOKS LIKE TWO TENTHS OF AN INCH SOUTHEAST TO TWO THIRDS OF
AN INCH NORTHWEST. COLDER AIR AND LAKE EFFECT SNOW SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR CTZ001.
NY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ038>041-
043-047>054-058-061-063-082>084.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ032-
033-042.
MA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
WIND ADVISORY UNTIL NOON EST TODAY FOR MAZ001.
VT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
WIND ADVISORY UNTIL NOON EST TODAY FOR VTZ013-014.
&&
$$
SYNOPSIS...11/NAS
NEAR TERM...11
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...BGM
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
938 AM EST THU JAN 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS INDIANA THIS MORNING. THEN A
STRONG UPPER LOW WILL MOVE ACROSS SOUTHERN INDIANA THIS EVENING AND
TO THE EASTERN GREAT LAKES FRIDAY. AN UPPER LEVEL DISTURBANCE WILL
TRACK ACROSS THE MID MISSISSIPPI AND OHIO VALLEYS LATE SATURDAY.
IN THE EXTENDED THE UPPER FLOW BECOMES MORE ZONAL EARLY NEXT WEEK
CAUSING TEMPERATURES TO MODERATE. AN UPPER DISTURBANCE WILL AFFECT
OUR WEATHER BY LATE MONDAY AND A COLD FRONT WILL MOVE ACROSS OUR
REGION TUESDAY. HIGH PRESSURE BEHIND THIS FRONT WILL BUILD ACROSS
OUR REGION BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
MAIN FOCUS WILL BE WORSENING WEATHER CONDITIONS LATER TODAY AND
WHETHER TO MAKE ANY CHANGES TO PREVIOUS PACKAGE. THE RAIN FROM
YESTERDAYS SYSTEM HAD MOVED OUT AND SNOW WAS BEGINNING TO SPREAD
INTO INTO WESTERN ILLINOIS. THE RAPID REFRESH BRINGS SNOW INTO
WESTERN INDIANA BY 15Z AND MOST OTHER AREAS MIDDAY OR LATER. MOST
OF THE SIGNIFICANT ACCUMULATIONS WILL BE THIS AFTERNOON AND WINDS
WILL BE INCREASING THEN TOO. WILL BEGIN WINTER WEATHER ADVISORY
ACROSS OUR FORECAST AREA AROUND NOON AND CONTINUE IT TO 1 PM
TOMORROW.
THE NAM AND CANADIAN MODELS INDICATE SLIGHTLY LOWER PRECIP AMOUNTS
ACROSS OUR SOUTHEAST. A LITTLE MORE THAN A HALF INCH. ON THE OTHER
HAND...THE EUROPEAN AND GFS MODELS ARE LITTLE CHANGED FROM PREVIOUS
RUNS. WILL SLOWER AMOUNTS SLIGHTLY ACROSS OUR SOUTHEAST HALF
TODAY...BUT STILL ENOUGH TO SUPPORT THE WINTER WEATHER ADVISORY AS
WINDS INCREASE CAUSING BLOWING AND DRIFTING SNOW BY TONIGHT.
AS FAR AS TEMPERATURES...WENT WITH A BLEND OF SREF 2 METER
TEMPERATURES AND MAV/MET HOURLY NUMBERS. TEMPERATURES WILL FALL
INTO THE MID 20S MOST AREAS BY THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MODELS ARE INDICATING THAT BEST TIME FRAME FOR SNOW ACCUMULATION
WILL BE FRI 00-06Z TONIGHT. BEST QVECTOR CONVERGENCE AND
FRONTOGENETIC BANDING WILL BE ACROSS THE NORTHERN COUNTIES OF
FORECAST AREA. TOTAL ACCUMULATIONS BY FRIDAY MORNING WILL RANGE FROM
1 TO 2 INCHES SOUTHERN SECTIONS...2 TO 3 INCHES ALONG THE INTERSTATE
70 CORRIDOR TO AROUND 3 TO 5 INCHES NEAR KOKOMO.
ISENTROPIC LIFT WILL ALSO BE BEST OVER THE NORTHERN COUNTIES...WITH
MOISTURE LACKING OVER THE SOUTHERN COUNTIES. SATURATION IN THE
DENDRITIC GROWTH ZONE WAS NOT OVERLY IMPRESSIVE EITHER...WHICH WILL
LIMIT SNOWFALL.
WRAPAROUND MOISTURE WILL RESULT IN SNOW SHOWERS ACROSS THE
NORTHEAST QUADRANT THROUGH FRIDAY MORNING. HOWEVER...THE MAIN
THREAT ON FRIDAY WILL BE THE STRONG WEST WINDS WITH SUSTAINED
SPEEDS OF 15 TO 25 MPH AND GUSTS TO 30 MPH. THIS WILL CREATE
BLOWING AND DRIFTING SNOW AND REDUCED VISIBILITIES. AS A
RESULT...CARRIED THE WINTER WEATHER ADVISORY TO FRI 18Z.
COLD ARCTIC AIR WILL SIT ACROSS CENTRAL INDIANA IN WAKE OF THIS
SYSTEM INTO THE WEEKEND. MODELS HAVE TRENDED A LITTLE COLDER FRIDAY
THROUGH SATURDAY AND WITH A COUPLE OF INCHES OF SNOW COVER...SEE NO
REASON NOT TO FOLLOW THIS TREND.
WEAK AREA OF HIGH PRESSURE WILL MOVE ACROSS OUR REGION LATE FRIDAY
NIGHT AND EARLY SATURDAY. THEN MODELS BRING A FAST MOVING CLIPPER
INTO THE OHIO VALLEY BY LATE SATURDAY. WESTERN AND SOUTH CENTRAL
SECTIONS COULD SEE UP TO AN INCH BY SATURDAY EVENING BEFORE THIS
SYSTEM MOVES OFF QUICKLY TO THE EAST SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
UPPER RIDGING BUILDS IN AND MOVES ACROSS THE AREA SUNDAY AND SUNDAY
NIGHT BRINGING IN SOME DRY AIR AND SCATTERING OUT SKY COVER. DURING
THE DAY MONDAY THE AREA WILL BE ON THE BACK SIDE OF THE RIDGE WITH
AN UPPER TROUGH TO THE EAST AND A COLD FRONT FIRMING UP OVER THE
PLAINS. THIS WILL ALLOW WARM ADVECTION TO RAMP UP AND ISENTROPIC
LIFT TO ENTER THE AREA BRINGING SMALL CHANCES FOR RAIN ON MONDAY. BY
MONDAY NIGHT THE LIFT REALLY INCREASES AHEAD OF THE COLD FRONT AND
MOISTURE SHOULD BE STREAMING UP FROM THE GULF ON A 50+ KT LOW LEVEL
JET. THOUGHT THE LIKELY POPS FROM THE ALLBLEND MATCHED UP WITH THIS
WELL. GFS AND ECMWF HAVE A BIT OF A DIFFERENCE IN THE TIMING OF THE
COLD FRONTAL PASSAGE TUESDAY WHICH COULD MAKE A DIFFERENCE IN HIGH
TEMPERATURES FOR THE DAY AS WELL AS HOW LONG PRECIPITATION CHANCES
WILL LAST AND WHETHER THEY WILL BE IN THE FORM OF RAIN OR SNOW. WITH
THE MORE ZONAL PATTERN FAVORING THE FASTER GFS BUT RECENT
VERIFICATION FAVORING THE ECMWF WILL USE THE ALLBLEND AVERAGE FOR
CHANCE POPS ACROSS THE AREA AND GO WITH RAIN AND SNOW UNTIL BETTER
AGREEMENT EMERGES. TUESDAY NIGHT LOOKS DRY. MODELS SHOW THE NEXT
SYSTEM ARRIVING IN THE WEDNESDAY NIGHT TO THURSDAY NIGHT TIME
SPAN BRINGING ANOTHER QUICK SHOT OF COLD AIR AND POSSIBLE PRECIP
CHANCES...BUT THOSE ARRIVE AFTER THE FORECAST PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 121500Z KIND TAF UPDATE/...
RADAR TRENDS SUGGEST THE ARRIVAL OF THE SNOW AT KIND MAY BE SOONER
THAN WHAT IS CURRENTLY IN THE FORECAST. WILL NUDGE UP THE ARRIVAL OF
THE SNOW AND ASSOCIATED IFR VISIBILITY RESTRICTIONS TO AROUND
121600Z. UPSTREAM OBSERVATIONS ACROSS ILLINOIS SUGGEST POTENTIAL FOR
A PERIOD OF LIFR VISIBILITY RESTRICTIONS LATER THIS AFTERNOON. MAY
NEED TO ADD THIS IN LATER UPDATES. PREVIOUS DISCUSSION FOLLOWS.
SITES WILL START OFF LOW MVFR OR IFR DUE TO CEILINGS WITH MAINLY
MVFR VISIBILITIES. THESE CONDITIONS SHOULD CONTINUE FOR THE NEXT FEW
HOURS UNTIL SNOW SHOWERS BEGIN TO ARRIVE IN THE WEST AROUND 15Z AND
SPREAD NORTH AND EAST IMPACTING ALL THE SITES BY 18Z. USED TIMING OF
ARRIVAL FROM RUC AND HRRR...WHICH WERE AN HOUR OR SO FASTER THAN THE
VSREFS. WITH SOME ECHOES LOOKING PRETTY STRONG IN THE HRRR FOR THE
INITIAL WAVE OF SNOW THAT MOVES THROUGH DID INCLUDE A TEMPO GROUP OF
LOWER VISIBILITIES. USED THE VSREFS TO COME UP WITH 1 1/2SM FOR ALL
THE SITES FOR A COUPLE OF HOURS AFTER SNOW BEGINS. AFTER THIS
INITIAL SHOT SNOW WILL BE MORE SHOWERY AND ON AND OFF IN NATURE AND
THINK IFR CEILINGS WITH MVFR VISIBILITIES SHOULD COVER THIS WELL.
LATER TONIGHT AROUND 0Z COULD SEE ANOTHER BOUT OF HEAVIER SNOW
SHOWERS AGAIN WITH WIDESPREAD VISIBILITIES AROUND A MILE AND A
HALF...BUT THESE CONDITIONS SHOULD IMPROVE SOMEWHAT AFTER 6Z TO MORE
WIDESPREAD LOW MVFR.
WINDS WILL BE AN ISSUE TODAY AND THEIR BLOWING OF THE SNOW COULD
SERVE TO DECREASE VISIBILITIES AS WELL. GUSTS IN THE TEENS COULD
START WITHIN THE NEXT COUPLE OF HOURS AND WILL ONLY SEE SUSTAINED
SPEEDS AND GUSTS INCREASE THROUGHOUT THE DAY WITH GUSTS AROUND 30
KTS BY 0Z AND LASTING THROUGHOUT THE OVERNIGHT. WINDS WILL MAINLY BE
WESTERLY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM NOON TODAY TO 1 PM EST FRIDAY FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...JH
LONG TERM....CP
AVIATION...CP/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
601 AM EST THU JAN 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS INDIANA THIS MORNING. THEN A
STRONG UPPER LOW WILL MOVE ACROSS SOUTHERN INDIANA THIS EVENING AND
TO THE EASTERN GREAT LAKES FRIDAY. AN UPPER LEVEL DISTURBANCE WILL
TRACK ACROSS THE MID MISSISSIPPI AND OHIO VALLEYS LATE SATURDAY.
IN THE EXTENDED THE UPPER FLOW BECOMES MORE ZONAL EARLY NEXT WEEK
CAUSING TEMPERATURES TO MODERATE. AN UPPER DISTURBANCE WILL AFFECT
OUR WEATHER BY LATE MONDAY AND A COLD FRONT WILL MOVE ACROSS OUR
REGION TUESDAY. HIGH PRESSURE BEHIND THIS FRONT WILL BUILD ACROSS
OUR REGION BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
MAIN FOCUS WILL BE WORSENING WEATHER CONDITIONS LATER TODAY AND
WHETHER TO MAKE ANY CHANGES TO PREVIOUS PACKAGE. THE RAIN FROM
YESTERDAYS SYSTEM HAD MOVED OUT AND SNOW WAS BEGINNING TO SPREAD
INTO INTO WESTERN ILLINOIS. THE RAPID REFRESH BRINGS SNOW INTO
WESTERN INDIANA BY 15Z AND MOST OTHER AREAS MIDDAY OR LATER. MOST
OF THE SIGNIFICANT ACCUMULATIONS WILL BE THIS AFTERNOON AND WINDS
WILL BE INCREASING THEN TOO. WILL BEGIN WINTER WEATHER ADVISORY
ACROSS OUR FORECAST AREA AROUND NOON AND CONTINUE IT TO 1 PM
TOMORROW.
THE NAM AND CANADIAN MODELS INDICATE SLIGHTLY LOWER PRECIP AMOUNTS
ACROSS OUR SOUTHEAST. A LITTLE MORE THAN A HALF INCH. ON THE OTHER
HAND...THE EUROPEAN AND GFS MODELS ARE LITTLE CHANGED FROM PREVIOUS
RUNS. WILL SLOWER AMOUNTS SLIGHTLY ACROSS OUR SOUTHEAST HALF
TODAY...BUT STILL ENOUGH TO SUPPORT THE WINTER WEATHER ADVISORY AS
WINDS INCREASE CAUSING BLOWING AND DRIFTING SNOW BY TONIGHT.
AS FAR AS TEMPERATURES...WENT WITH A BLEND OF SREF 2 METER
TEMPERATURES AND MAV/MET HOURLY NUMBERS. TEMPERATURES WILL FALL
INTO THE MID 20S MOST AREAS BY THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MODELS ARE INDICATING THAT BEST TIME FRAME FOR SNOW ACCUMULATION
WILL BE FRI 00-06Z TONIGHT. BEST QVECTOR CONVERGENCE AND
FRONTOGENETIC BANDING WILL BE ACROSS THE NORTHERN COUNTIES OF
FORECAST AREA. TOTAL ACCUMULATIONS BY FRIDAY MORNING WILL RANGE FROM
1 TO 2 INCHES SOUTHERN SECTIONS...2 TO 3 INCHES ALONG THE INTERSTATE
70 CORRIDOR TO AROUND 3 TO 5 INCHES NEAR KOKOMO.
ISENTROPIC LIFT WILL ALSO BE BEST OVER THE NORTHERN COUNTIES...WITH
MOISTURE LACKING OVER THE SOUTHERN COUNTIES. SATURATION IN THE
DENDRITIC GROWTH ZONE WAS NOT OVERLY IMPRESSIVE EITHER...WHICH WILL
LIMIT SNOWFALL.
WRAPAROUND MOISTURE WILL RESULT IN SNOW SHOWERS ACROSS THE
NORTHEAST QUADRANT THROUGH FRIDAY MORNING. HOWEVER...THE MAIN
THREAT ON FRIDAY WILL BE THE STRONG WEST WINDS WITH SUSTAINED
SPEEDS OF 15 TO 25 MPH AND GUSTS TO 30 MPH. THIS WILL CREATE
BLOWING AND DRIFTING SNOW AND REDUCED VISIBILITIES. AS A
RESULT...CARRIED THE WINTER WEATHER ADVISORY TO FRI 18Z.
COLD ARCTIC AIR WILL SIT ACROSS CENTRAL INDIANA IN WAKE OF THIS
SYSTEM INTO THE WEEKEND. MODELS HAVE TRENDED A LITTLE COLDER FRIDAY
THROUGH SATURDAY AND WITH A COUPLE OF INCHES OF SNOW COVER...SEE NO
REASON NOT TO FOLLOW THIS TREND.
WEAK AREA OF HIGH PRESSURE WILL MOVE ACROSS OUR REGION LATE FRIDAY
NIGHT AND EARLY SATURDAY. THEN MODELS BRING A FAST MOVING CLIPPER
INTO THE OHIO VALLEY BY LATE SATURDAY. WESTERN AND SOUTH CENTRAL
SECTIONS COULD SEE UP TO AN INCH BY SATURDAY EVENING BEFORE THIS
SYSTEM MOVES OFF QUICKLY TO THE EAST SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
UPPER RIDGING BUILDS IN AND MOVES ACROSS THE AREA SUNDAY AND SUNDAY
NIGHT BRINGING IN SOME DRY AIR AND SCATTERING OUT SKY COVER. DURING
THE DAY MONDAY THE AREA WILL BE ON THE BACK SIDE OF THE RIDGE WITH
AN UPPER TROUGH TO THE EAST AND A COLD FRONT FIRMING UP OVER THE
PLAINS. THIS WILL ALLOW WARM ADVECTION TO RAMP UP AND ISENTROPIC
LIFT TO ENTER THE AREA BRINGING SMALL CHANCES FOR RAIN ON MONDAY. BY
MONDAY NIGHT THE LIFT REALLY INCREASES AHEAD OF THE COLD FRONT AND
MOISTURE SHOULD BE STREAMING UP FROM THE GULF ON A 50+ KT LOW LEVEL
JET. THOUGHT THE LIKELY POPS FROM THE ALLBLEND MATCHED UP WITH THIS
WELL. GFS AND ECMWF HAVE A BIT OF A DIFFERENCE IN THE TIMING OF THE
COLD FRONTAL PASSAGE TUESDAY WHICH COULD MAKE A DIFFERENCE IN HIGH
TEMPERATURES FOR THE DAY AS WELL AS HOW LONG PRECIPITATION CHANCES
WILL LAST AND WHETHER THEY WILL BE IN THE FORM OF RAIN OR SNOW. WITH
THE MORE ZONAL PATTERN FAVORING THE FASTER GFS BUT RECENT
VERIFICATION FAVORING THE ECMWF WILL USE THE ALLBLEND AVERAGE FOR
CHANCE POPS ACROSS THE AREA AND GO WITH RAIN AND SNOW UNTIL BETTER
AGREEMENT EMERGES. TUESDAY NIGHT LOOKS DRY. MODELS SHOW THE NEXT
SYSTEM ARRIVING IN THE WEDNESDAY NIGHT TO THURSDAY NIGHT TIME
SPAN BRINGING ANOTHER QUICK SHOT OF COLD AIR AND POSSIBLE PRECIP
CHANCES...BUT THOSE ARRIVE AFTER THE FORECAST PERIOD.
&&
.AVIATION /DISCUSSION FOR 121200Z TAF ISSUANCE/...
SITES WILL START OFF LOW MVFR OR IFR DUE TO CEILINGS WITH MAINLY
MVFR VISIBILITIES. THESE CONDITIONS SHOULD CONTINUE FOR THE NEXT FEW
HOURS UNTIL SNOW SHOWERS BEGIN TO ARRIVE IN THE WEST AROUND 15Z AND
SPREAD NORTH AND EAST IMPACTING ALL THE SITES BY 18Z. USED TIMING OF
ARRIVAL FROM RUC AND HRRR...WHICH WERE AN HOUR OR SO FASTER THAN THE
VSREFS. WITH SOME ECHOES LOOKING PRETTY STRONG IN THE HRRR FOR THE
INITIAL WAVE OF SNOW THAT MOVES THROUGH DID INCLUDE A TEMPO GROUP OF
LOWER VISIBILITIES. USED THE VSREFS TO COME UP WITH 1 1/2SM FOR ALL
THE SITES FOR A COUPLE OF HOURS AFTER SNOW BEGINS. AFTER THIS
INITIAL SHOT SNOW WILL BE MORE SHOWERY AND ON AND OFF IN NATURE AND
THINK IFR CEILINGS WITH MVFR VISIBILITIES SHOULD COVER THIS WELL.
LATER TONIGHT AROUND 0Z COULD SEE ANOTHER BOUT OF HEAVIER SNOW
SHOWERS AGAIN WITH WIDESPREAD VISIBILITIES AROUND A MILE AND A
HALF...BUT THESE CONDITIONS SHOULD IMPROVE SOMEWHAT AFTER 6Z TO MORE
WIDESPREAD LOW MVFR.
WINDS WILL BE AN ISSUE TODAY AND THEIR BLOWING OF THE SNOW COULD
SERVE TO DECREASE VISIBILITIES AS WELL. GUSTS IN THE TEENS COULD
START WITHIN THE NEXT COUPLE OF HOURS AND WILL ONLY SEE SUSTAINED
SPEEDS AND GUSTS INCREASE THROUGHOUT THE DAY WITH GUSTS AROUND 30
KTS BY 0Z AND LASTING THROUGHOUT THE OVERNIGHT. WINDS WILL MAINLY BE
WESTERLY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM NOON TODAY TO 1 PM EST FRIDAY FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...JH
LONG TERM....CP
AVIATION...CP
AREA FORECAST DISCUSSION
NWS GRAY ME
900 AM EST THU JAN 12 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE SOUTH TODAY AND WILL MOVE INTO
THE GULF OF MAINE BY THIS EVENING. LOW PRESSURE WILL WEAKEN AS IT
MOVES INTO THE MARITIMES TONIGHT. AT THE SAME TIME...ANOTHER AREA
OF LOW PRESSURE WILL APPROACH NEW ENGLAND FROM THE WEST. LOW
PRESSURE WILL MOVE NORTHEAST THROUGH NORTHERN NEW ENGLAND ON
FRIDAY SWINGING A TRAILING COLD FRONT THROUGH THE AREA AND SETTING
UP A STRONG SOUTHWEST FLOW IN IT`S WAKE. A TROUGH OF LOW PRESSURE
WILL LINGER OF THE AREA FRIDAY NIGHT AND WILL MOVE OFFSHORE ON
SATURDAY. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST
SATURDAY NIGHT THROUGH SUNDAY. HIGH PRESSURE WILL CREST OVER THE
REGION ON MONDAY AND SHIFT OFFSHORE IN THE AFTERNOON. A COLD FRONT
WILL APPROACH FROM THE NORTHWEST MONDAY NIGHT THROUGH TUESDAY. LOW
PRESSURE WILL DEVELOP ALONG THE FRONT AND WILL MOVE INTO NORTHERN
NEW ENGLAND BY WEDNESDAY MORNING SWINGING THE FRONT THROUGH THE
REGION. LOW PRESSURE WILL RACE OFF TO THE NORTHEAST ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
...BANDS OF HEAVY SNOW ABOUT TO ENTER MAINE AND NEW HAMPSHIRE
QUICKLY FROM THE SOUTH...
COASTAL FRONT IN FULL SWING ALONG THE COAST WITH TEMPERATURES
FALLING QUICKLY ALONG THE SHORELINE. PORTLAND NOW DOWN TO 25
DEGREES...JUST WEST OF THE COASTAL FRONT (HAVE LOWERED MAX TEMP
FCST AND DEW POINT VALUES FOR TODAY). THIS COLD/DRY AIR WILL
CONTINUE TO FUNNEL DOWN THE COAST...AND WE HAVE ALREADY BEGUN TO
ADJUST SNOWFALL TOTALS UPWARDS ALONG PORTIONS OF THE COAST.
BEST PRESSURE FALLS WITH THE SURFACE LOW NOW SOUTH OF LONG ISLAND.
BELIEVE MODELS ARE OVERDOING THE WARM AIR...BOTH AT THE SURFACE
AND ALOFT. COASTAL ROCKINGHAM COUNTY AND SOUTHERNMOST PORTIONS OF
YORK COUNTY HOWEVER STILL REMAIN RELATIVELY VULVERNABLE TO THE MIX
OR CHANGEOVER TO RAIN. HOWEVER...WE ARE DELAYING THIS ONSET OF
MIXED PCPN BY A COUPLE HOURS THIS MORNING.
TIDES ARE STARTING TO RUN PRETTY HIGH ALONG THE COAST...WITH
BUILDING WAVES ALONG WITH DEVELOPING GALE FORCE WINDS. EXPECT
SPLASH-OVER NEAR THE TIME OF HIGH TIDE AND WILL ADD THIS TO
STATEMENTS AND/OR THE HWO SHORTLY.
WARNINGS/ADVISORIES...ALL LOOKS GOOD AT THE MOMENT. AM MONITORING
PORTIONS OF SOUTH-CENTRAL HAMPSHIRE AND THE MAINE COASTLINE FOR
POSSIBLE UPGRADES TO ADDITIONAL WARNINGS. WILL TAKE A QUICK LOOK
AT THE NEW NAM - WITH ONLY MODEST INTEREST AS IT HAS BEEN WAY TOO
WARM...BUT STRONG ON THE QPF FOR SW ME AND SE NH PROVIDING 1+" QPF
AS OF THE 06Z RUN. THIS AFTER RUNNING RELATIVELY DRY AT 00Z. MORE
IMPORTANTLY...WE`RE TAKING A GOOD LOOK AT THE LATEST HRRR MODEL
RUN. THIS MODEL BRINGS THE LOW OFF THE COAST OF MAINE LATER THIS
AFTERNOON AND BACKS WINDS WITH TIME...KEEPING WARM SURFACE AIR
OFFSHORE. HAVING MENTIONED SHORT RANGE GUIDANCE...WEIGHTING OF
THIS FORECAST IS HIGHLY DEPENDENT ON THE POSITIONING AND
ENHANCEMENT OF OUR FULLY DEVELOPED COASTAL FRONT.
PREV DISC...
LOW PRESSURE MOVING UP FROM THE SOUTH WILL BRING A VARIETY OF
PRECIPITATION TO THE REGION TODAY. EXPECT SNOW TO MOVE INTO
SOUTHERN NEW HAMPSHIRE AND SOUTHWEST MAINE THROUGH DAYBREAK. TEMPS
ALREADY IN THE MID 30S IN COASTAL AREAS SO EXPECT PRECIPITATION TO
GO OVER TO RAIN FAIRLY QUICKLY THIS MORNING IN SOUTHEAST NEW
HAMPSHIRE AND ADJACENT SOUTHWEST COASTAL MAINE. EVAPORATIONAL
COOLING AT THE ONSET MAY LAST LONG ENOUGH TO PRODUCE AN INCH OR
TWO OF SNOW IN THESE AREAS BEFORE CHANGEOVER.
FARTHER TO THE NORTH IN SOUTH CENTRAL NEW HAMPSHIRE EXPECT MORE IN
THE WAY OF SNOW BEFORE MIXING TAKES PLACE WITH 3 TO 6 INCHES
LIKELY THROUGH EARLY AFTERNOON. LOOKING FOR PRECIPITATION TO
REMAIN IN THE FORM OF SNOW FOR MUCH OF THE DAY IN NORTHERN NEW
HAMPSHIRE AND INTERIOR SECTIONS OF MAINE WHICH COULD SEE AS MUCH
AS 6 TO 10 INCHES BEFORE PRECIPITATION WINDS DOWN AS A PERIOD OF
SLEET OR LIGHT FREEZING RAIN LATE THIS AFTERNOON AND THIS EVENING.
WILL BE STICKING WITH CURRENT ADVISORIES AND WARNINGS WITH NO
CHANGES PLANNED. EXPECT HIGHS IN THE MID 30S TO NEAR 40 IN COASTAL
AREAS BUT COLD AIR WILL HANG TOUGH IN INTERIOR SECTIONS WHERE
HIGHS WILL ONLY REACH THE MID 20S TO LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
A LULL IN THE ACTION DURING THE FIRST HALF OF TONIGHT AS LOW
PRESSURE WEAKENS AND LIFTS NORTHEAST INTO THE MARITIMES. MAY SEE
SOME LIGHT PATCHY FREEZING DRIZZLE OR MIXED PRECIPITATION DURING
THE FIRST HALF OF THE NIGHT BUT ANY ACCUMULATIONS WILL BE MINOR.
LOW PRESSURE APPROACHING FROM THE GREAT LAKES WILL SWING AN
OCCLUSION NORTHEAST TOWARD NEW ENGLAND AFTER MIDNIGHT WHICH WILL
BRING ANOTHER ROUND OF MIXED PRECIPITATION INTO SOUTHWEST ZONES BY
DAYBREAK SO SOME FORM OF ADVISORIES MAY BE NEEDED FOR LATE TONIGHT
INTO FRIDAY.
EXPECT ACTIVITY ALONG THE BOUNDARY TO QUICKLY LIFT NORTHEAST
THROUGH THE REMAINDER OF THE FORECAST AREA DURING THE MORNING
HOURS...PERSISTING IN THE MOUNTAINS WELL INTO THE AFTERNOON WITH
MIXED PRECIPITATION CHANGING BACK TO SNOW AS COLDER AIR SHIFTS
BACK INTO THE REGION. COULD SEE SEVERAL INCHES OF ACCUMULATION
LATE IN THE DAY AS UPSLOPE FLOW KICKS IN BEHIND DEPARTING LOW.
ELSEWHERE RAIN AND MIXED PRECIPITATION WILL TAPPER TO SNOW SHOWERS
IN THE AFTERNOON.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A STRONG ARCTIC CD FNT MOVES THRU FRIDAY NGT BRINGING IN CD
CANADIAN AIR ON GUSTY W THEN NW WINDS. SHSN PSBL...THOUGH MOSTLY
CONFINED TO THE N/MT ZONES WHERE SOME ACCUMULATION PSBL. ELSEWHERE
DOWNSLOPE WINDS HELP TO MINIMIZE THE CHC OF ANY SHSN AND ALSO
DECREASES AMOUNT OF SKY COVER VERSUS THE N/MT ZONES. CD WX
DOMINATES THRU THE WEEKEND AS THE NW WIND FIELD SLOWLY EASES UP
WITH HIGH PRES APPROACHING FROM THE W. THE HIGH SETTLES OVER THE E
COAST MONDAY WITH FAIR BUT CONTINUED CD WX. THE HIGH MOVES OFF
SHORE TUESDAY ALLOWING SW FLOW TO BRING IN WARMER AIR. AN
APPROACHING CD FNT BRINGS A CHC OF -SHSN OR -SHRA TUESDAY AND
TUESDAY NGT. THE STRONG ARCTIC FNT MOVES BY FOR WEDNESDAY BRINGING
IN MORE VERY CD AND BLUSTERY WX.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR FRIDAY
NGT AND SATURDAY. USED GMOS FOR REST OF THE LONG TERM FCST... EXCEPT
USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND MIN TEMPS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHORT TERM...IFR/LIFR CEILINGS/VSBY DEVELOPING TODAY AND
PERSISTING THROUGH FRIDAY MORNING...IMPROVING IN THE AFTERNOON.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...STRONG ARCTIC CD FNT
MOVES THRU FRIDAY NGT WITH SHSN PSBL ALONG WITH MVFR TO IFR
CIG/VSBY...THOUGH MOST ACTIVITY CONFINED TO THE N/MT AREAS.
STRONG GUSTY W THEN NW WINDS FRIDAY NGT.
&&
.MARINE...
SHORT TERM...GALE WARNING EXTENDED THROUGH FRIDAY NIGHT.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...WILL EXTEND THE GLW
THRU FRIDAY NGT WITH EVEN A FEW PEAK GUSTS OF STORM FORCE PSBL AS
STRONG W FLOW SETS UP BEHIND DEPARTING STRONG CD FNT AND TIGHT
PRES GRADIENT SETS UP AND IS ENHANCED BY STRONG CD AIR ADVECTION
OVER THE WARMER WATERS. WINDS SLOWLY LET UP AND SEAS SLOWLY
SUBSIDE AS HIGH PRES BUILDS IN FROM THE W OVER THE WEEKEND AND
SETTLES OVER THE E COAST ON MONDAY.
&&
.TIDES/COASTAL FLOODING...
THE ASTRONOMICAL HIGH TIDE IN PORTLAND IS 10.3 FT ANEAR 1 PM THIS
AFTERNOON. A STORM SURGE OF 1 TO 1.5 FT IS EXPECTED TDA. THIS
WOULD PUSH THE TIDE TO AROUND 11.5 FT AND POSSIBLY CLOSE TO THE 12
FOOT TIDAL FLOOD STAGE. AT THIS TIME THE TIDE IS EXPECTED TO STAY
BELOW 12 FT. HOWEVER, BUILDING SEAS FROM ONSHORE WINDS WILL LIKELY
CREATE UP TO MODERATE SPLASHOVER AND BEACH EROSION AROUND THE TIME OF HIGH
TIDE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR
MEZ007>009-012>014-018>022.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MEZ023>028.
NH...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR
NHZ001>004-006.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NHZ005-007>010-013-014.
MARINE...GALE WARNING UNTIL 7 AM EST SATURDAY FOR ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
717 AM CST THU JAN 12 2012
.UPDATE...
/717 AM CST THU JAN 12 2012/
MAIN BAND OF SNOW CONTINUES TO MOVE/PIVOT EAST INTO
ILLINOIS...WITH SNOW SHOWERS AND FLURRIES LEFT IN ITS WAKE. MOST
REPORTS HAVE ACCUMULATION ANYWHERE BETWEEN 0.5 AND 1.5 INCHES.
THIS WAS ENOUGH SNOW TO CAUSE MAJOR TRAFFIC ISSUES ACROSS THE
AREA...WITH NUMEROUS ACCIDENTS REPORTED.
500MB LOW HAS CLOSED OFF ACCORDING TO THE RUC AND IS ABOUT TO
ROUND THE BASE OF THE TROF ACROSS SOUTHWEST MISSOURI. SHOULD SEE
SNOW BECOME BETTER ORGANIZED AGAIN LATER THIS MORNING AND INTO THE
AFTERNOON ACROSS NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS AS
DEEP CYCLONIC FLOW DEVELOPS AS 500MB LOW MOVES ACROSS SOUTHERN
ILLINOIS. THIS AREA OF SNOW MAY REACH AS FAR SOUTH AS ST. LOUIS
METRO. OTHERWISE...SNOW SHOWERS AND FLURRIES WILL CONTINUE FOR
MUCH OF THE DAY. WILL HAVE UPDATED FORECAST OUT IN A FEW MINUTES.
CVKING
&&
.DISCUSSION...
/338 AM CST THU JAN 12 2012/
N-S BAND OF POST FRONTAL LIGHT SNOW WAS MOVING FAIRLY RAPIDLY EWD
THROUGH OUR AREA EARLY THIS MRNG...CURRENTLY MOVING INTO THE ST
LOUIS METRO AREA. THIS WAS ASSOCIATED WITH LOW-MID LEVEL
FRONTOGENESIS BEHIND THE STRONG COLD FRONT WHICH MOVED THROUGH
WED EVNG. THIS BAND OF SNOW SHOULD MOVE E OF OUR FORECAST AREA BY
LATE MRNG. ADDITIONAL SNOW...MAINLY IN THE FORM OF LIGHT SNOW
SHOWERS CAN BE EXPECTED LATE THIS MRNG AND AFTN AS AN UPPER LEVEL
LOW CUTS OFF OVER NERN KS IN THE BASE OF THE UPPER LEVEL TROUGH
EXTENDING FROM WRN MN S THROUGH ERN KS. THIS UPPER LEVEL LOW WILL
DROP E-SEWD THROUGH SRN PORTIONS OF MO AND IL TODAY. THE BEST SNOW
AMOUNTS WILL FALL LEFT OF THE TRACK OF THE UPPER LEVEL LOW. LIGHT
SNOW SHOWERS OR FLURRIES WILL LINGER OVER MAINLY IL TGT WITH
LITTLE ADDITIONAL ACCUMULATION EXPECTED TGT. TOTAL SNOW
ACCUMULATION FROM WED NIGHT AND THU SHOULD RANGE FROM ONE INCH
ACROSS PORTIONS OF SERN MO TO AROUND 2 INCHES IN THE ST LOUIS METRO
AREA TO 3 INCHES OVER PARTS OF WEST CENTRAL IL. A WINTER WEATHER
ADVISORY WILL CONTINUE TODAY OVER THE ENTIRE FORECAST AREA. STRONG
AND GUSTY NWLY SFC WINDS CAN BE EXPECTED TODAY INTO THIS EVNG DUE
TO A TIGHT SFC PRESSURE GRADIENT OVER OUR AREA BETWEEN A SFC LOW
OVER THE GREAT LAKES REGION AND THE LARGE AND STRONG SFC RIDGE
OVER THE PLAINS AND ROCKIES. BELOW NORMAL TEMPERATURES CAN BE
EXPECTED TODAY WITH THE MODELS DROPPING THE -16 DEGREE C 850 MB
ISOTHERM SEWD THROUGH MUCH OF OUR AREA TODAY BEHIND THE UPPER/SFC
LOW. PLUS LOW LEVEL CLOUD COVER AND LIGHT SNOW WILL LEAD TO LITTLE
DIURNAL RISE IN TEMPERATURES TODAY WITH HIGHS ONLY IN THE 20S.
WILL GO BELOW MOS GUIDANCE FOR THE TEMPERATURE FORECAST DUE TO
THE SNOW COVER EXPECTED. LOWS TGT AND FRI NGT SHOULD BE IN THE
TEENS...POSSIBLY IN THE SINGLE DIGITS WHERE THERE IS BETTER SNOW
COVER. THE SKY SHOULD SLOWLY CLEAR OUT LATE TGT AND FRI FROM THE
SW TO NE. TEMPERATURES WILL BE WARMER ON SAT AS THE SFC WIND BACKS
AROUND TO A SWLY DIRECTION AHEAD OF AN APPROACHING SFC TROUGH...AND
AS LOW LEVEL WAA INCREASES AHEAD OF THIS TROUGH. THE MODELS ARE
FORECASTING A NW FLOW SHORTWAVE TO DROP SEWD THROUGH ERN MO AND IL
ON SAT WITH A BAND OF LIGHT PRECIPITATION LEFT OF THE TRACK OF THE
VORT MAX ACROSS IL. IT SHOULD BE COLD ENOUGH FOR THIS PRECIPITATION
TO FALL AS SNOW. THE NAM MODEL APPEARS OVERDONE WITH THE QPF BUT
MAY BE ABLE TO PICK UP A DUSTING OF SNOW OVER THE NRN AND ERN
PORTIONS OF THE FORECAST AREA FROM THIS FAST MOVING SYSTEM.
TEMPERATURES SHOULD BE EVEN WARMER ON SUN AS THE UPPER LEVEL
HEIGHTS RISE AND THE SFC WIND BECOMES SLY. THE NEXT CHANCE OF
PRECIPITATION SHOULD BEGIN ON MON WITH TEMPERATURES WARM ENOUGH
THAT IT SHOULD FALL AS LIQUID RAIN. THE PRECIPITATION MAY CHANGE
TO SNOW BEFORE ENDING ON TUE AS COLDER AIR FILTERS SEWD INTO THE
REGION BEHIND A COLD FRONT.
GKS
&&
.AVIATION...
/507 AM CST THU JAN 12 2012/
BAND OF LIGHT TO MODERATE SNOW WILL CONTINUE TO PUSH EAST THIS
MORNING...WITH REDEVELOPMENT OF SNOW SHOWERS EXPECTED IN ITS WAKE
AS THE UPPER LOW CONTINUES TO DIG ACROSS MISSOURI AND ILLINOIS.
NORTHWEST WINDS TO REMAIN STRONG AND GUSTY...WITH BLOWING SNOW AND
REDUCED VISIBILITY. SNOW SHOWERS WILL TAPER TO FLURRIES THIS
EVENING AND SKIES WILL SCT OVERNIGHT. TOTAL ACCUMULATION OF 1 TO 3
INCHES IS EXPECTED.
SPECIFICS FOR KSTL...
BAND OF MODERATE SNOW WILL BE PULLING EAST OF THE TERMINAL AROUND
12Z...WITH LIGHT SNOW CONTINUING THIS MORNING...AND SNOW SHOWERS
INTO THE AFTERNOON. VISIBILITY WILL VARY...AND BE TIED TO BLOWING
SNOW DUE TO STRONG AND GUSTY NORTHWEST WINDS. EXPECT A TOTAL SNOW
ACCUMULATION OF 1 TO 2 INCHES. CONDITIONS TO IMPROVE THIS EVENING
WITH VFR CONDITIONS RETURNING.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR AUDRAIN
MO-BOONE MO-CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-
GASCONADE MO-IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN
MO-MADISON MO-MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-
OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES
MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE.
GENEVIEVE MO-WARREN MO-WASHINGTON MO.
IL...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR ADAMS IL-
BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-
MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON
IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1020 AM EST THU JAN 12 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL CAUSE BREEZY
WESTERLY WINDS ACROSS THE CAROLINAS AND SOUTHERN VIRGINIA TODAY. A
POLAR COLD FRONT WILL CROSS THE REGION TONIGHT. MUCH COOLER AIR WILL
SETTLE OVER THE AREA FRIDAY AND LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM THURSDAY...
DEEP BUT TEMPORARY WEST-SOUTHWESTERLY FLOW OBSERVED OVER CENTRAL NC
THIS MORNING AS ONE LOW PRESSURE SYSTEM IS LIFTING TOWARD NEW
ENGLAND AND A SECOND CLIPPER LOW IS DIVING THROUGH THE MIDWEST
STATES. THE AIRMASS AROUND THE SOUTHEAST IS FAIRLY UNIFORM...SO
HIGHS TODAY WILL MOSTLY BE DEPENDING ON MIXING AS GRADIENT WINDS
INCREASE AHEAD OF THE APPROACHING DEEP CLIPPER SYSTEM. FORECAST
SOUNDINGS SHOW MIXING TO AROUND 900MB...WHICH MAY BE SLIGHTLY
UNDERDONE GIVEN THAT WINDS ARE ALREADY INCREASING TO 12-15KT AND
WILL EVENTUALLY GUST TO NEAR 25KT THIS AFTERNOON. A RIBBON OF
STRATUS TRAPPED BELOW THE SUBSIDENCE INVERSION OVER THE FOOTHILLS
AND WESTERN PIEDMONT HAS RESISTED MIXING SO FAR...AND ALSO A LARGE
AREA IF STRATUS IS ADVANCING THROUGH UPSTATE SC AND MAY BLEED INTO
AREAS NEAR THE YADKIN RIVER. CLOUD COVER WILL BE ADJUSTED OVER THE
WESTERN COUNTIES BASED ON SOME OF THE HRRR AVIATION GUIDANCE AND
TEMPS MAY ULTIMATELY BE HELD DOWN A COUPLE OF DEGREES IN THE WEST.
EXPECT HIGHS OF 58-65 NORTHWEST TO SOUTHEAST. -SMITH
AS THE UPPER TROUGH AND SFC COLD FRONT CROSSES THE MTNS THIS
EVENING...STRONG FRONTOGENETIC FORCING WITHIN UPPER JET EXIT REGION
WILL SUPPORT A BAND OF SHALLOW CONVECTION THAT WILL QUICKLY MOVE
EAST ACROSS CENTRAL NC BETWEEN 00 TO 06Z. MOISTURE WILL BE LIMITED
WITH EXPECTED SCATTERED SHOWERS TENDING TO DRY UP/DISSIPATE AS THEY
ADVANCE EAST OFF THE HIGHER TERRAIN AS FLOW QUICKLY BECOMES WESTERLY
WITH STRONG DRY COLD AIR ADVECTION ENSUING. ANY PRECIP WILL BE ALL
LIQUID WITH COLD AIR TRAILING THE EXITING SHALLOW MOIST LAYER. SKIES
SHOULD CLEAR OFF MIDNIGHT WITH CAA PLUNGING TEMPERATURES DOWN INTO
THE LOWER 30S NORTHWEST TO MID/UPPER 30S SOUTHEAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 315 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
A TIGHT PRESSURE GRADIENT WILL CONTINUE ON FRIDAY BETWEEN THE
DEEPENING LOW PRESSURE OVER NEW ENGLAND AND SURFACE HIGH PRESSURE
OVER THE GULF COAST STATES. INVERSELY TO TODAY...THESE WINDS WILL
EXACERBATE THE BUILDING ARCTIC AIRMASS AS LOW-LEVEL THICKNESSES 12Z
FRIDAY MORNING ARE FORECAST TO START OUT 30 METERS BELOW
NORMAL...SUPPORTING HIGHS IN THE LOWER 40S NW TO UPPER 40S
SOUTHEAST...WITH BLUSTERY WESTERLY WINDS PRODUCING WIND CHILLS
OF 35 TO 40. PRESSURE GRADIENT RELAXES FRIDAY EVENING/NIGHT AS LOW
OVER NEW ENGLAND CONTINUES TO MOVE AWAY. COLD OVERNIGHT LOWS IN THE
IN THE LOWER TO MID 20S.
SATURDAY...L/W TROUGH OVER THE EASTERN HALF OF THE U.S WILL MAINTAIN
COOLER THAN NORMAL CONDITIONS ACROSS OUR REGION. 850MB THERMAL
TROUGH LIES ACROSS THE REGION SATURDAY WITH 850MB TEMPS MINUS
6-MINUS 8 DEGREES C. THICKNESSES 30-35M BELOW NORMAL WHICH WOULD
YIELD MAX TEMPS NO HIGHER THAN THE UPPER 30S TO NEAR 40 IN THE
PIEDMONT. ADJUSTING FOR POTENTIAL AIR MASS MODIFICATION...EXPECT MAX
TEMPS IN THE LOW-MID 40S OVER THE PIEDMONT AND NORTHERN COASTAL
PLAIN..AND UPPER 40S ACROSS THE FAR SOUTH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 315 AM THURSDAY...
SATURDAY NIGHT...MODEL GUIDANCE HAS TRENDED FARTHER SOUTH WITH A
VORT MAX IN THE NW FLOW TRAVERSING SEWD ON THE BACK SIDE OF THE
TROUGH. DUE TO THE MORE SOUTHWARD PATH OF THE VORT MAX INTO THE BASE
OF THE UPPER TROUGH OVER OUR REGION...WE HAVE A BETTER CHANCE OF
SEEING MORE CLOUDS AND POSSIBLY SOME LIGHT PRECIP. 00Z GFS
RH/TEMP/LIFT CROSS SECTION FOR 06Z SUNDAY DOES DEPICT ADEQUATE
MOISTURE AND LIFT IN THE FAVORED ICE NUCLEATION REGION TO GENERATE
SNOWFLAKES ALOFT. HOWEVER THE LIFT DOES NOT EXTEND DOWN INTO THE
LOWEST 8K FT OF THE ATMOSPHERE PLUS THE SUBCLOUD LAYER IS QUITE DRY
SUGGESTING A HIGH PROBABILITY OF EVAPORATION. PARTIAL THICKNESSES
SUGGEST THAT ANY PRECIP THAT DOES REACH THE SURFACE WOULD BE LIGHT
SNOW. SINCE THIS IS THE FIRST ITERATION OF THIS POSSIBLE SCENARIO BY
THE MODELS...AND THE NEAR SURFACE CONDITIONS NOT IDEAL FOR
PRECIP...WILL REFRAIN FROM MENTIONING PRECIP IN THE FORECAST AT THIS
TIME. IF PRECIP WERE TO OCCUR...WOULD EXPECT NOTHING MORE THAN A FEW
SNOW FLURRIES...MAINLY LATE SATURDAY EVENING INTO THE OVERNIGHT
HOURS. DUE TO THE INCREASE IN CLOUD COVERAGE...EXPECT MIN
TEMPS TO BE A COUPLE OF DEGREES WARMER THAN FRIDAY NIGHT. MOST
PLACES SHOULD BE IN THE UPPER 20S.
SUNDAY INTO MONDAY...STRONG SUBSIDENCE IN THE WAKE OF THE EXITING
VORT MAX SUNDAY MORNING WILL LEAD TO CLEARING SKIES WITH SUNNY SKIES
EXPECTED AREAWIDE BY EARLY AFTERNOON. NW FLOW AT 850MB IN THE WAKE
OF THE SYSTEM SUNDAY DEPICT NEUTRAL ADVECTION AT THIS TIME.
LINGERING EFFECTS OF 850MB THERMAL TROUGH OVER THE REGION SHOULD
YIELD MAX TEMPS SLIGHTLY BELOW NORMAL. AFTERNOON TEMPS IN THE
MID-UPPERS 40S PROJECTED.
SURFACE RIDGE OVER THE REGION SUNDAY NIGHT SHOULD CREATE IDEAL
CONDITIONS FOR RADIATIONAL COOLING. MIN TEMPS MID 20S WITH LOWER
20S POSSIBLE IN THE NORMALLY COLDER LOCALES.
MODEST RECOVERY BEGINS MONDAY AS SURFACE RIDGE SHIFTS EAST AND
RETURN FLOW COMMENCES LATE IN THE DAY. AIR MASS MODIFICATION SHOULD
RESULT IN MAX TEMPS CLOSE TO NORMAL FOR MID JANUARY...UPPER 40S TO
THE LOWER 50S.
MONDAY NIGHT INTO TUESDAY...MODELS HAVE TRENDED WETTER WITH THIS
PARTICULAR MODEL RUN. BOTH THE 00Z GFS AND 00Z ECMWF PAINT LIGHT
PRECIP OVER CENTRAL NC MONDAY NIGHT IN THE LOW LEVEL WAA REGIME.
ISENTROPIC UPGLIDE APPEARS TO BE BEST IN THE 285-290K LAYER. WHILE
CANNOT RULE SPOTTY PRECIP...LOW LEVEL AIR MASS WILL BE QUITE DRY
MONDAY WITH DEWPOINTS IN THE TEENS. THUS THE PRECIP GENERATED BY THE
MODELS MAY ACTUALLY GO INTO MOISTENING THE SUB CLOUD LAYER TO
SATURATION. WILL KEEP POPS BELOW 20 PERCENT BUT DID RAISE MIN TEMPS
A COUPLE OF DEGREES DUE TO THICKENING CLOUDS.
NEXT MID-UPPER LEVEL S/W IN THE BROAD TROUGH OVER THE EASTERN U.S.
PROJECTED TO ADVANCE EAST FROM THE MID MS VALLEY INTO THE OH VALLEY
TUESDAY. THIS FEATURE WILL INDUCE WSW FLOW ALOFT. MEANWHILE N-S
ORIENTATION OF THE SURFACE RIDGE OFF THE EASTERN SEABOARD YIELDS A
LOW LEVEL S-SW FLOW OVER THE CAROLINAS ORIGINATING FROM THE CENTRAL
GULF. THIS SUGGEST A SHOT OF LOW LEVEL MOISTURE TRANSPORT INTO OUR
REGION AHEAD OF THE S/W AND ATTENDANT SURFACE FRONT. SINCE WE ARE
TALKING ABOUT DAY6/7...WILL ADJUST POP ONLY A TAD TO ABOUT 30
PERCENT IN THE WEST AND MAINTAIN A SLIGHT CHANCE IN THE EAST. MODEL
TIMING SUGGEST HIGHEST THREAT FOR PRECIP TUESDAY AFTERNOON-EARLY
TUESDAY NIGHT. SYSTEM EXITS REGION WEDNESDAY LEADING TO CLEARING
SKIES. TEMPS BEHIND FRONT WILL BE SLIGHTLY COOLER BUT NOT
OUTRAGEOUSLY COLD SINCE HIGH APPEARS TO BE OF PACIFIC ORIGIN WITH
SOME MODIFIED CP INFLUENCE.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 630 AM THURSDAY...
24-HR TAF PERIOD:
LOW-LEVEL MOISTURE HAS SCATTERED OUT ACROSS CENTRAL NC AS VIGOROUS
LOW PRESSURE SYSTEM ACCELERATES NORTHEASTWARD AWAY FROM THE AREA.
DEEP CYCLONIC FLOW AHEAD OF A DEEPENING LOW PRESSURE SYSTEM MOVING
THROUGH THE OHIO AND TN VALLEYS WILL RESULT IN BREEZY SWLY WINDS
TODAY WITH SCATTERED STRATOCU CLOUD BASES BETWEEN 3 TO 4KFT.
AN ARCTIC COLD FRONT WILL MOVE ACROSS THE AREA BETWEEN 00 TO 06
FRIDAY...PRODUCING A SMALL 3-5 HOUR WINDOW OF MVFR CEILINGS WITH
WIDELY SCATTERED TO ISOLATED RAIN SHOWERS. SKIES WILL QUICKLY CLEAR
OUT BEHIND THE FRONTAL PASSAGE TONIGHT.
LOOKING AHEAD:
VFR CONDITIONS WILL PREVAIL THROUGH THE WEEKEND IN ASSOC/W A
COLD/DRY AIRMASS IN PLACE. BREEZY CONDITIONS CAN BE EXPECTED AGAIN
ON FRIDAY WITH WEST-SOUTHWESTERLY WIND GUSTS OF 25 TO 30 MPH
EXPECTED. THE ONLY POTENTIAL FOR SUB-VFR CONDITIONS WOULD BE A
SHORT PERIOD SATURDAY NIGHT/SUNDAY MORNING IN ASSOC/W A CLIPPER
SYSTEM PROGRESSING ACROSS THE AREA IN NW FLOW ALOFT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...CBL/SMITH
SHORT TERM...CBL/WSS
LONG TERM...WSS
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
839 AM CST THU JAN 12 2012
.DISCUSSION...FORECAST IN GENERALLY GOOD SHAPE THIS MORNING AND
HAVE MADE LITTLE OVERALL CHANGE. LATEST OBS AND PROFILER DATA
COUPLED WITH 12Z RAOB APPEAR TO SHOW A RELATIVE MAXIMUM IN THE LOW
LEVEL PRESSURE GRADIENT FROM AROUND PORT ISABEL NORTHWARD TO NEAR
VICTORIA TEXAS. LATEST RUC SEEMS TO HANDLE THIS VERY WELL SHOWING
A PERIOD OVER THE NEXT COUPLE OF HOURS WHERE OCCASIONAL GUSTS TO
AROUND 40 MPH WILL BE POSSIBLE OVER LAND...WITH FREQUENT GALES
OVER THE COASTAL WATERS. NAM/RUC CROSS SECTIONS SHOW THE VERTICAL
PRESSURE GRADIENT AND RESULTANT DOWNWARD FORCING RELAXING AS THE
BOUNDARY LAYER EXPANDS DUE TO SURFACE HEATING THIS MORNING AND
AS A RESULT PROGS EASING WINDS AFTER ABOUT 18Z WHICH APPEARS VERY
REASONABLE. HAVE ISSUED A SHORT TERM FORECAST TO MENTION THE INCREASED
WIND POTENTIAL FOR THE NEXT COUPLE OF HOURS...BUT FALLING BELOW
ADVISORY CRITERIA FOR NOW. SEE FIRE WEATHER DISCUSSION BELOW FOR
CHANGES TO THE FIRE WEATHER FORECAST PACKAGE. /68-JGG/
&&
.FIRE WEATHER...SEEING MORE FREQUENT SUSTAINED WINDS OVER 25 MPH
BEGINNING TO COME IN THIS MORNING SLIGHTLY FURTHER WEST THAN
ORIGINALLY ANTICIPATED. WITH RH EXPECTED TO WELL EXCEED CRITICAL
THRESHOLDS...AND WINDS SHOWING SIGNS OF ALSO DOING SO HAVE
EXPANDED THE RED FLAG WARNING TO INCLUDE ALL BUT ZAPATA COUNTY IN
OUR CWA UNTIL 4PM THIS AFTERNOON. /68/
&&
.PREV DISCUSSION... /ISSUED 545 AM CST THU JAN 12 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...MVFR CONDITIONS WITH BKN020 LOW CLOUDS NEAR THE COAST
WITH THE RECENT PASSAGE OF A COLD FRONT. SKC UPSTREAM AND EXPECT
SOME CLEARING THIS MORNING BEFORE THICKER LOW CLOUDS DEVELOP
TONIGHT. OTHERWISE...BREEZY AND GUSTY NORTH WINDS TODAY...
DECREASING TONIGHT.
PREV DISCUSSION... /ISSUED 306 AM CST THU JAN 12 2012/
SHORT TERM /TODAY THROUGH FRIDAY/...
A COLD FRONT WILL PRETTY MUCH HAVE ARRIVED THROUGH THE CWA AS WE
OPEN THE FORECAST TODAY. BEHIND THE FRONT...AN AIR MASS WITH
MARITIME POLAR CHARACTERISTICS WILL BE ARRIVING ALONG A LINE THAT
STRETCHED NORTHWEST INTO THE PACIFIC NORTHWEST. WE ARE LOOKING FOR
BREEZY AND GUSTY NORTH WINDS EARLY ON TODAY...ESPECIALLY IN COASTAL
AREAS...WITH BKN LOW CLOUDS ALONG THE COLD FRONT THIS MORNING GIVING
WAY TO A TEMPORARY BREAK UP OF CLOUDS THIS AFTERNOON. THEN COLDER
AIR WILL EVENTUALLY RESULT IN BKN TO OVC SKIES DEVELOPING BY FRIDAY.
NO PRECIP IS FORECAST FOR TODAY...WITH HIGH TEMPERATURES REMAINING
LIMITED TO THE 50S. HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT WITH
LIGHT WINDS...AND LOW TEMPERATURES WILL DIP WELL BELOW NORMAL FRIDAY
MORNING. MAV GUIDANCE NUMBERS ACROSS THE NORTHERN TIER ARE JUST
ABOVE FREEZING...AND WE MAY SEE A FEW SPOTS HIT THE FREEZING MARK OR
BELOW FRIDAY MORNING...BUT WITH A RECOGNIZED COLD BIAS...WILL STOP
SHORT OF A FREEZE WATCH RIGHT NOW AND JUST GO WITH AN SPS FOR THE
NORTHERN COUNTIES TONIGHT. TEMPS FRIDAY WILL RECOVER INTO THE 60S
WITH LIGHT NORTHEAST TO EAST WINDS. /54/
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE WILL FLATTEN AND BEGIN TO SHIFT EAST FRIDAY
NIGHT/SATURDAY...AS A SHORTWAVE TROUGH HEADS TOWARD THE TENNESSEE
AND OHIO RIVER VALLEYS. WINDS SHOULD BECOME INCREASINGLY EASTERLY
AS THIS OCCURS...AND COULD RESULT IN A GRADUAL INCREASE IN GULF
MOISTURE OVER THE AREA HEADING INTO THE WEEKEND.
WEATHER CONDITIONS HEADING INTO THE WEEKEND SHOULD BE RATHER QUIET
/FOR THE MOST PART/. BOUNDARY LAYER MOISTURE /ALTHOUGH INCREASING/
SHOULD REMAIN RATHER LIMITED FOR THE FIRST HALF OF THE WEEKEND...AS
A BIT OF SHORTWAVE RIDGING MOVES ACROSS THE REGION. A FEW
PERTURBATIONS ARE SHOWN BY THE MODELS IN THE UPPER ATMOSPHERE JUST
TO OUR NORTH...BUT THESE ARE LIKELY REFLECTIONS OF THE SUBTROPICAL
JET. SO DESPITE AN EXPECTED INCREASE IN CLOUD COVER FOR THE
WEEKEND...LITTLE /IF ANY/ RAINFALL IS ANTICIPATED AT LEAST THROUGH
SATURDAY.
A FLY IN THE OINTMENT REMAINS THE DEVELOPMENT OF A COASTAL
TROUGH...WHICH CONTINUES TO BE SHOWN TO VARYING DEGREES BY MOST OF
THE MEDIUM-RANGE MODELS EARLY THIS MORNING. AS WINDS BECOME
SOUTHEASTERLY ACROSS THE REGION SUNDAY MORNING...LOOK FOR LOW-LEVEL
MOISTURE TO DEEPEN AT A RATHER QUICK PACE. IN FACT...PRECIPITABLE
WATER VALUES SHOULD RISE ABOVE 1.4 TO 1.5 INCHES FOR MUCH OF
SUNDAY. AND WITH THE DEPARTURE OF THE SHORTWAVE RIDGE...SOME OF THE
PERTURBED UPPER-LEVEL ENERGY TO OUR NORTH COULD WORK ITS WAY
SOUTHWARD. PLENTY OF ISENTROPIC UPGLIDE AND LOW CONDENSATION
PRESSURE DEFICITS ON THE 305K THETA SURFACE SHOULD ALSO BE AVAILABLE.
DISPENSING WITH THE WEATHER SPEAK...ALL OF THIS WILL LIKELY LEAD TO
THE POSSIBILITY OF SOME LIGHT RAIN FOR SUNDAY. RIGHT NOW...I THINK
THE GREATEST ODDS OF SEEING RAIN WILL LIKELY OCCUR EASTWARD OF THE
MIDDLE VALLEY. AS SUCH...I WILL LIKELY INCREASE THE ODDS OF SEEING
RAIN IN THESE REGIONS FOR SUNDAY. JUST A SIDE NOTE -- PROBABILITIES
IN THE NUMERICAL GUIDANCE PROBABILITIES HAVE REMAINED IN A NEARLY
STEADY-STATE MODE OVER THE PAST 4 OR 5 MODEL CYCLES. WHILE NOT THE
ONLY JUSTIFICATION FOR INCREASING RAIN PROBABILITIES...THIS DOES
INCREASE MY CONFIDENCE THAT SOMEONE WILL SEE MEASURABLE RAINFALL
ACROSS THIS REGION.
WHAT APPEARS TO BE OUR BEST OPPORTUNITY TO SEE SOME RAIN THIS
WEEKEND WILL BE RATHER SHORT-LIVED...AS MOST OF THE SYNOPTIC SCALE
FORCING SHOULD EXIT THE AREA BY MONDAY. WE WILL THEN START WATCHING
THE PROGRESSION OF AN UPPER LOW...WHICH SHOULD MOVE ONSHORE THE
SOCAL/BAJA CALIFORNIA COAST SUNDAY NIGHT. IT NOW LOOKS LIKE THIS
FEATURE SHOULD WEAKEN TO AN OPEN WAVE AS IT HEADS ACROSS THE DESERT
SOUTHWEST...AND WILL PROBABLY DO A BIT OF PHASING WITH ANOTHER
UPPER-LEVEL SYSTEM MOVING THROUGH THE NORTHERN ROCKIES.
THE EASTWARD MOVEMENT OF THIS SYSTEM SHOULD ALLOW A COLD FRONT TO
MOVE SOUTHWARD ACROSS MID-AMERICA EARLY IN THE WEEK. IT LOOKS LIKE
THE FRONT SHOULD MOVE INTO NORTH TEXAS LATE MONDAY NIGHT/TUESDAY
MORNING...THEN ACROSS OUR CORNER OF THE WORLD SOMETIME TUESDAY
NIGHT. TIMING OF THIS SYSTEM PRESENTED BY AVAILABLE MEDIUM-RANGE
GUIDANCE IS DEBATABLE. MOST MODELS PUSH THE FRONT SOUTH OF THE RIO
GRANDE BY WEDNESDAY MORNING. MEANWHILE...GUIDANCE FROM THE
HYDROMETEOROLOGICAL PREDICTION CENTER LAGS BEHIND THE OPERATIONAL
MODELS SOME 6 TO 12 HOURS. STAY TUNED.
FOR NOW...IT DOES NOT LOOK LIKE WE WILL SEE MUCH IN THE WAY OF
PRECIPITATION WITH THIS SYSTEM. WITH LOW-LEVEL MOISTURE SOMEWHAT
LIMITED...I WILL KEEP RAIN PROBABILITIES AT OR BELOW 14 PERCENT WITH
THIS FORECAST PACKAGE.
HIGHS WILL LIKELY WARM INTO THE 70S BY THIS WEEKEND...BUT MAY FALL
INTO THE 60S BY WEDNESDAY DEPENDING ON THE TIMING OF THE FRONT.
LOWS WILL LIKELY GO ABOVE NORMAL IN MOST PLACES GIVEN THE EXPECTED
CLOUD COVER DURING MOST PERIODS THROUGH NEXT WEDNESDAY. /53/
MARINE...
TODAY THROUGH FRIDAY...A COLD FRONT AND STRONG MARITIME POLAR HIGH
PRESSURE WILL SET UP GALE FORCE GUSTS THIS MORNING THROUGH LATE THIS
AFTERNOON ON THE GULF...WHILE SMALL CRAFT ADVISORY CONDITIONS WILL
EXIST ON THE LAGUNA MADRE. WAVE HEIGHTS WILL LIKELY BUILD TO 12 FEET
OFFSHORE. SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY CONTINUE ON
THE GULF TONIGHT BUT CONDITIONS WILL IMPROVE FRIDAY AS HIGH PRESSURE
SPREADS OUT AND SETTLES OVER THE AREA. /54/
FRIDAY NIGHT THROUGH MONDAY...NORTHEAST TO EAST WINDS SHOULD BECOME
SOUTHEAST ACROSS THE MARINE AREA BY SUNDAY AS SURFACE HIGH PRESSURE
SHIFTS EAST. WINDS AND SEAS SHOULD REMAIN BELOW EXERCISE CAUTION OR
ADVISORY CRITERIA THROUGH MOST OF THE WEEKEND. WIND SPEEDS IN WAKE
OF A COASTAL TROUGH MAY INCREASE A BIT FOR SUNDAY NIGHT AND
MONDAY...AND COULD RESULT IN THE POSTING OF SMALL CRAFT EXERCISE
CAUTIONS OR SMALL CRAFT ADVISORIES BY THIS TIME. /53/
FIRE WEATHER...
NORTH WINDS AT 20 FEET WILL PEAK AT AROUND NOON TODAY BETWEEN 15 AND
20 MPH WITH GUSTS TO 25 MPH FOR THE INLAND AREAS...BUT THE DRIEST
AIR WILL NOT BECOME ESTABLISHED UNTIL MID AFTERNOON...JUST WHEN 20
FOOT WINDS BEGIN DECREASING. THE RELEVANT WEATHER ELEMENTS WILL THUS
BE SLIGHTLY OUT OF PHASE. MEETING THE CRITERIA FOR A RED FLAG
WARNING WILL BE MARGINAL INLAND...BUT WILL BE JUSTIFIABLE NEAR THE
COAST WHERE STRONGER WINDS OF NEAR 25 MPH AT 20 FEET WILL PREVAIL.
AS MENTIONED EARLIER...FIRE DANGER CRITERIA WILL BE MET FOR THE REST
OF THE CWA INLAND FOR SEVERAL HOURS FROM ABOUT 9 AM TO 3 PM CST
TODAY. ZAPATA COUNTY WILL BE MOST MARGINAL FOR THE FIRE DANGER
STATEMENT...WITH FORECAST RELATIVE HUMIDITY VALUES BARELY DECREASING
TO 25 PERCENT...BUT FELT IT WAS CLOSE ENOUGH TO INCLUDE. /54/
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...RED FLAG WARNING UNTIL 4 PM CST THIS AFTERNOON FOR TXZ249>257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CST THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST FRIDAY
FOR GMZ150-155-170-175.
GALE WARNING UNTIL 3 PM CST THIS AFTERNOON FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/59/58
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1100 AM MST THU JAN 12 2012
.UPDATE...FEW CHANGES NEEDED FOR THE SHORT TERM. ANY BLOWING SNOW
THAT OCCURS SHOULD BE VERY LOCALIZED AND CAN BE HANDLED BY
NOWCASTS. SO WILL NOT EXTEND THE PATCHY BLOWING SNOW GRID INTO
THIS AFTERNOON. MODELS CONTINUE TO SHOW A WEAKENING GRADIENT
ACROSS THE PLAINS THIS EVENING...WOULD EXPECT A DECREASE IN WINDS
AS A RESULT. WATER VAPOR LOOPS SHOW SOME SORT OF A WEAK WAVE
MOVING INTO WESTERN WYOMING...WITH MAINLY HIGH LEVEL MOISTURE.
MODELS DON`T SEEM TO PICK UP THIS FEATURE...WILL NEED TO MONITOR
FOR ANY TYPE OF WIND INCREASE AS THIS FEATURE MOVES AWAY FROM THE
AREA.
&&
.AVIATION...DELAYED THE SHIFT TO NORTHWEST AT AREA AIRPORTS TIL
20Z...AS SHOWN BY RUC. NAM AND HRRR KEEP THE SOUTHWEST WINDS
PREVAILING. NOT SURE ABOUT THE GFS AND THE WEAK EASTERLIES.
WILL MONITOR FOR ANY DEVELOPMENT OF A DENVER CYCLONE.
OTHERWISE...TAF TRENDS SEEM REASONABLE.
&&
.PREV DISCUSSION... /ISSUED 251 AM MST THU JAN 12 2012/
SHORT TERM...NW FLOW ALOFT WILL BE OVER THE AREA TODAY. GUSTY
WINDS WILL BE POSSIBLE IN THE MTNS AND ALONG THE FOOTHILLS THRU THE
MORNING HOURS WITH A FEW AREAS OF BLOWING SNOW. OVER NERN CO GUSTY
NWLY WINDS WILL ALSO OCCUR WHICH WILL LINGER THROUGH THE AFTN HOURS
BUT SPEEDS SHOULD STAY BLO HIGHLIGHT CRITERIA. AS FOR HIGHS WILL
KEEP READINGS MAINLY IN THE 35 TO 40 DEGREE RANGE OVER NERN CO.
FOR TONIGHT A WEAK UPPER LEVEL TROUGH IN NW FLOW WILL MOVE ACROSS
THE AREA HOWEVER CROSS-SECTIONS SHOW MOISTURE CONFINED TO THE MID
AND UPPER LEVELS. THUS WILL SEE AN INCREASE IN CLOUDS WITH ONLY A
FEW FLURRIES OVER THE HIGHER MTN PEAKS. LATE TONIGHT AS SUBSIDENCE
DEVELOPS BEHIND PASSAGE OF WEAK UPPER LEVEL TROUGH WINDS MAY
INCREASE IN AND NR THE FOOTHILLS HOWEVER SPEEDS SHOULD REMAIN BLO
WARNING CRITERIA.
LONG TERM...MODELS HAVE STRONG NORTHERLY FLOW ALOFT FOR THE
FORECAST AREA ON FRIDAY...WITH AN UPPER RIDGE TO OUR WEST.
DECREASING NORTHWESTERLY FLOW ALOFT IS PROGGED FOR FRIDAY NIGHT
THROUGH SATURDAY. BY SATURDAY NIGHT...WEAK ZONAL FLOW ALOFT IS
PROGGED. THE QG VERTICAL VELOCITY FIELDS HAVE WEAK DOWNWARD MOTION
PROGGED FOR THE CWA THROUGH SATURDAY NIGHT. THE BOUNDARY LAYER FLOW
LOOKS TO BE A MIX OF THE NORMAL DIURNAL PATTERN COUPLED WITH
DOWNSLOPING WITH TROUGHING EAST OF THE MOUNTAINS THROUGH THE
PERIOD. FOR MOISTURE...THERE IS A BIT IN THE MID AND UPPER LEVELS
THROUGH THE PERIOD. THE IS NO MEASURABLE PRECIPITATION ON THE QPF
FIELDS THROUGH THE PERIOD. NO POPS. CROSS SECTIONS SHOW A BIT OF
MOUNTAINS WAVE SET UP FRIDAY AFTERNOON AND NIGHT. HOWEVER...IT IS
NOT SIGNIFICANT. FOR TEMPERATURES...FRIDAY`S HIGHS ARE 2-5 C WARMER
THAN TODAY`S. SATURDAY`S WARM-UP ANOTHER 2-4 C. WILL UNDERCUT MOS
GUIDANCE NUMBERS...ESPECIALLY IN THE AREAS WHERE THERE IS SNOW ON
THE GROUND. FOR THE LATER DAYS...SUNDAY THROUGH WEDNESDAY...ZONAL
FLOW GIVES WAY TO SOUTHWESTERLY FLOW ALOFT ON SUNDAY AND SUNDAY
NIGHT. THE ECMWF AND GFS BOTH SHOW A BROAD UPPER TROUGH TO MOVE
INTO COLORADO LATER MONDAY AND MONDAY NIGHT. BOTH HAVE A COLD FRONT
AND UPSLOPE FOR THE PLAINS AND FOOTHILLS MONDAY AFTERNOON AND
EVENING. IT IS A QUICK SHOT. FOR TUESDAY AND WEDNESDAY...
NORTHWESTERLY FLOW ALOFT IS PROGGED...AND THERE IS MOISTURE WITH
IT. PERHAPS OUR MOUNTAINS WILL SEE SOME SNOW. WILL LEAVE THE
EXTENDED GFE GRIDS PRETTY MUCH ALONE.
AVIATION...VFR THRU TONIGHT. WILL KEEP WINDS SSW THRU THE MORNING
HOURS AROUND 10 KTS. BY AFTN HRRR KEEPS WINDS MAINLY WSW WHILE THE
RUC HAS THEM SHIFTING TO MORE OF A WNW DIRECTION WITH SPEEDS AROUND
10 KTS. FOR NOW WILL TREND TOWARDS A WNW DIRECTON. BY EARLY
EVENING WINDS WILL GRADUALLY BECOME MORE WSW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS NEW YORK NY
105 PM EST THU JAN 12 2012
.SYNOPSIS...
A STORM SYSTEM FROM THE OHIO VALLEY TO THE SOUTHERN NEW ENGLAND
COAST WILL MOVE SLOWLY TO THE NORTH AND EAST THROUGH FRIDAY. A
STRONG COLD FRONT WILL MOVE ACROSS THE REGION EARLY FRIDAY
MORNING. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING LOW THROUGH
THE WEEKEND. HIGH PRESSURE REMAINS INTO THE BEGINNING OF THE WEEK.
ANOTHER COLD FRONT MOVES THROUGH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GREATEST PRESSURE FALLS WERE JUST OFF THE SE NEW ENGLAND COAST
LATE THIS MORNING. THIS WOULD SUPPORT THE COASTAL LOW TO THE
SOUTH OF LI TAKING A TRACK TO THE E/SE OF THE TRI-STATE AREA.
12Z NAM AND RUC SUPPORT SUCH A TRACK. THIS WILL IN PART PRODUCE
SOMEWHAT COOLER HIGHS TODAY...ESPECIALLY ACROSS THE INTERIOR...BUT
ALSO KEEP THE WINDS IN A MORE NORTHERLY DIRECTION. IN ADDITION...A
STRONG NE FLOW CONTINUES ACROSS COASTAL LOCATIONS THIS MORNING WITH
GUSTS UP TO 30 MPH. THE GRADIENT WILL SLACKEN BY THIS AFTERNOON AS
THE LOW TRACKS TO THE NE OF THE AREA. MORE IMPORTANTLY...THIS MAY
EXACERBATE COASTAL FLOODING ACROSS LI SOUND THIS AFTERNOON. REFER
TO THE COASTAL FLOOD SECTION BELOW.
AS FOR THE RAIN AND EMBEDDED THUNDERSTORMS...THE MAIN AREA ACROSS
EASTERN CT AND EASTERN LI WILL LIFT TO THE NE AND CLEAR THE AREA
BY NOONTIME. THERE MAY BE PATCHES OF LIGHT RAIN THROUGH THE
AFTERNOON WITH WEAK LIFT AND MOISTURE IN PLACE.
DUE TO THE LOW TRACK...HIGHS WERE ADJUSTED DOWNWARD SEVERAL
DEGREES...MAINLY ACROSS THE INTERIOR. HIGHS MAY NOT GET OUT OF
THE UPPER 30S WELL INLAND. ELSEWHERE...TEMPS SHOULD HOLD STEADY
OR SLIGHTLY FALL FROM THEIR CURRENT READINGS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
NEXT UPPER TROUGH AND VORT SWINGS THROUGH THE AREA IN ASSOCIATION
WITH THE SURFACE LOW OVER THE OHIO VALLEY. PRECIPITATION WILL MOVE
BACK IN QUICKLY THIS EVENING IN THE WARM AIR AHEAD OF A STRONG
COLD FRONT. PRECIPITATION WILL BE MORE SHOWERY...AND ALL RAIN AS
COLD AIR LAGS UNTIL AFTER THE PRECIPITATION ENDS.
STRONG FRONT SWEEPS THROUGH LATE TONIGHT INTO EARLY FRIDAY
MORNING. WITH STRONG COLD ADVECTION AND MIXING OF 40 TO 50 KT LOW
LEVEL WINDS ADVISORY LEVEL GUSTS WILL BE LIKELY DURING FRIDAY.
WITH A STRONG PRESSURE GRADIENT EVEN SOME OF THE SUSTAINED WINDS
WILL BE NEAR ADVISORY LEVELS. COLD ADVECTION SUBSIDES IN THE
AFTERNOON WITH SUBSIDING WINDS. HIGHS WILL LIKELY OCCUR EARLY IN
THE MORNING WITH TEMPERATURES FALLING THROUGH THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WINDS WILL SLOWLY DIMINISH LATE FRI NIGHT...BUT SHOULD PICK UP
AGAIN SAT MORNING THOUGH NOT REACHING SPEEDS QUITE AS HIGH AS
THOSE OF FRI. SLOW MOVING SFC COLD FRONT DROPPING DOWN FROM THE N
WILL MAINTAIN CLOUDS ESPECIALLY ACROSS INTERIOR SECTIONS. THIS
FRONT SHOULD MOVE THROUGH SAT NIGHT...FINALLY USHERING IN SOME
VERY COLD AIR FOR SAT NIGHT THROUGH MON AS STRONG CANADIAN HIGH
PRES BUILDS ACROSS.
AS THE HIGH MOVES TO THE EAST MON NIGHT INTO TUE...RETURN FLOW
BETWEEN THE HIGH AND AN APPROACHING COLD FRONT WILL BRING QUICK
MODERATION TO SEVERAL DEG ABOVE NORMAL TUE INTO TUE EVENING.
DEEP LAYER WAA AHEAD OF THE FRONT WILL SUPPORT A LARGE SWATH OF
PRE-FRONTAL CLOUDS TUE INTO TUE NIGHT...ALSO A FEW RAIN/SNOW SHOWERS
MAINLY TUE NIGHT. FAIR WX WITH NEAR AVG TEMPERATURES WILL RETURN FOR
WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
LOW PRESSURE PASSES JUST SOUTH OF LONG ISLAND THIS AFTERNOON. A
POWERFUL COLD FRONT PASSES FRI MRNG.
SCATTERED AREAS OF LIGHT RAIN IN THE AREA THIS AFTERNOON. TEMPO
MVFR VSBYS PSBL WITH -RA AND BR. MODERATE CONFIDENCE REGARDING
CEILING FORECAST. CIGS MAY DROP TO IFR AT SOME TERMINALS. WIND
FORECAST ALSO MODERATE CONFIDENCE. TREND WILL BE WINDS SHIFTING TO
THE N-NW THEN EVENTUALLY W-SW...BUT TIMING MAY NEED TO BE AMENDED.
SUSTAINED WIND SPEEDS AND GUSTS DIMINISH...BUT AMENDMENTS ALSO
POSSIBLE FOR TIMING.
LOW CIGS EXPECTED TO CONTINUE TONIGHT...WITH A SMALL CHANCE THAT
SOME TERMINALS MAY LIFT TO VFR THIS EVENING.
COLD FRONT APPROACHES TOWARDS MORNING. MODERATE CONFIDENCE OF
RAINFALL...WITH POSSIBILITY THAT SOME TERMINALS SEE EITHER BRIEF
OR NO RAIN. CIGS COULD ALTERNATE BETWEEN MVFR AND IFR. ALSO CHANCE
OF SNOW MIXED WITH RAIN AT KSWF.
HIGH CONFIDENCE OF GUSTY WINDS FRIDAY...BEGINNING IN THE MORNING.
COULD SEE GUSTS AS HIGH AS 40KT AT TIMES. HIGH CONFIDENCE OF WIND
DIRECTION LEFT OF 310 AT NYC TERMINALS. VFR BY LATE MORNING.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE TO REFINE TIMING OF WIND SHIFTS
THIS AFTERNOON...BUT SHOULD TREND TO NW AND THEN WSW. GUSTS MAY
DIMINISH EARLIER THAN FORECAST. PERIODIC MVFR VSBYS PSBL.
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE TO REFINE TIMING OF WIND SHIFTS
THIS AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN WSW. SW FLOW
MAY DEVELOP HERE EARLIER THAN AT KLGA/KEWR. GUSTS MAY DIMINISH
EARLIER THAN FORECAST. IFR CIGS AND MVFR VSBYS PSBL AT TIMES.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE TO REFINE TIMING OF WIND SHIFTS
THIS AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN WSW. SW FLOW
MAY DEVELOP HERE EARLIER THAN AT KLGA/KEWR. GUSTS MAY DIMINISH
EARLIER THAN FORECAST. OCCASIONAL IFR CIGS/VSBYS POSSIBLE.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE TO REFINE TIMING OF WIND SHIFTS
THIS AFTERNOON...BUT SHOULD TREND TO NW AND THEN WSW. SW FLOW MAY
DEVELOP HERE EARLIER THAN AT KLGA/KEWR. CIGS/VSBYS MAY FLUCTUATE
BETWEEN MVFR AND IFR AT TIMES.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE TO REFINE TIMING OF WIND SHIFTS
THIS AFTERNOON...BUT SHOULD TREND TO NW AND THEN WSW. CIGS MAY
FLUCTUATE BETWEEN MVFR AND IFR AT TIMES. CHANCE OF MVFR VSBYS.
KISP FCSTER COMMENTS: CIGS MAY VARY BETWEEN IFR AND MVFR. MVFR
VSBYS MAY LINGER LONGER THAN FORECAST. AMENDMENTS POSSIBLE TO REFINE
TIMING WIND SHIFTS THIS AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN
WSW. GUSTS MAY DIMINISH EARLIER THAN FORECAST.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
FRI AFTERNOON...VFR. WIND GUSTS AROUND 35KT...POSSIBLY EXCEEDING
40 KT AT TIMES.
SAT...VFR. FLURRIES POSSIBLE. GUSTY NW-W WINDS.
SUN-MON...VFR.
TUE...SUB-VFR PSBL.
&&
.MARINE...
GALES REMAIN UP ON ALL THE WATERS THIS MORNING. A STRONG LOW
LEVEL JET ASSOCIATED WITH AN AREA OF LOW PRESSURE PASSING OVER THE
AREA WATERS WILL MIX DOWN TO THE SURFACE BRINGING A PERIOD OF
STRONG GUSTY WINDS THIS MORNING. THE STRONGEST WINDS ARE EXPECTED
BETWEEN 5 AM AND 10 AM...WITH SOME LINGERING STRONGER GUSTS ACROSS
THE EASTERN WATERS. WINDS THEN RAPIDLY DIMINISH TO SMALL CRAFT
LEVELS THIS AFTERNOON. THERE MAY EVEN BE A PERIOD WHERE WINDS FALL
BELOW SMALL CRAFT LEVELS OVERNIGHT OUT AHEAD OF THE NEXT COLD
FRONT. SEAS HOWEVER WILL REMAIN AT SCA LEVELS.
SOUTHERLY WINDS RAPIDLY INCREASE ONCE AGAIN...THIS TIME OUT AHEAD
OF A COLD FRONT FRIDAY MORNING. HIGH CONFIDENCE EXISTS FOR STRONG
WESTERLY GALES DEVELOPING FRIDAY AND FRIDAY NIGHT BEHIND THE COLD
FRONT...WITH GUSTS UP TO 45 KT AND OCEAN SEAS BUILDING AS HIGH AS 16
FT OUT EAST FRI EVENING...AND UP TO 9 FT ON ERN LONG ISLAND SOUND.
THERE MAY EVEN BE A FEW GUSTS TO STORM FORCE. HAVE DECIDED NOT TO
ISSUE A NEW GALE WATCH OR WARNING FOR THIS EVENT TO AVOID CONFUSION
BETWEEN IT AND THE NEAR TERM FORECAST GALES...AS THERE SHOULD BE
ABOUT A 12-HR LULL BETWEEN THE TWO.
GALES SHOULD STILL BE ONGOING OVER THE OCEAN WATERS AND POSSIBLY THE
ERN SOUND/BAYS INTO SAT. GRADUAL IMPROVEMENT TO SUB-SCA EXPECTED SAT
NIGHT...WITH POSSIBLE OCEAN SCA CONDS RETURNING ON SUNDAY AS COLDER
AIR MOVES IN FROM THE NORTH.
&&
.HYDROLOGY...
RAINFALL AMOUNTS RANGED FROM 1 TO 1.5 INCHES FROM THIS EVENT. NO
FLOODING PROBLEMS ARE ANTICIPATED. AN ADDITIONAL TENTH TO TWO
TENTHS OF RAINFALL IS POSSIBLE LATE TONIGHT INTO FRIDAY MORNING.
DRY WEATHER RETURNS LATE FRIDAY THROUGH THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
THE COASTAL FLOOD ADVISORY HAS BEEN EXPANDED TO INCLUDE ALL ZONES
ADJACENT TO LI SOUND...AS WELL AS THE PECONIC AND GARDINERS BAYS.
THIS IS DUE TO A CHANGE IN LOW TRACK THAT HAS KEPT A STRONG...
PERSISTENT E/NE FLOW ACROSS LI SOUND. THIS HAS RESULTED IN
SIGNIFICANT TIDAL PILING WITH TIDAL DEPARTURES RUNNING AROUND 3
FT ABOVE NORMAL. THESE WATER LEVELS WILL BE SLOW TO RECEDE. IN FACT...
A COASTAL FLOOD WARNING MAY BE REQUIRED ACROSS WESTERN LI SOUND
SHOULD THESE LEVELS SHOW NO SIGH OF COMING DOWN IN THE NEXT HOUR.
THE COASTAL FLOOD ADVISORY ACROSS NY HARBOR AND THE SOUTH SHORE OF
WESTERN LI SOUND WILL EXPIRE AT NOON. THERE WAS WIDESPREAD MINOR
FLOODING ACROSS THESE AREAS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...COASTAL FLOOD ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
CTZ009>012.
NY...COASTAL FLOOD ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ078-079-081.
COASTAL FLOOD WARNING UNTIL 3 PM EST THIS AFTERNOON FOR NYZ071-
073-176-177.
NJ...NONE.
MARINE...GALE WARNING FROM 6 AM FRIDAY TO MIDNIGHT EST FRIDAY NIGHT FOR
ANZ330-335-338-340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-
335-340.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...KCS
MARINE...
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1241 PM EST THU JAN 12 2012
.SYNOPSIS...
LOW PRESSURE SOUTH OF LONG ISLAND WILL DRIFT TO OUR EAST THIS
AFTERNOON. ANOTHER LOW PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE
OHIO VALLEY TONIGHT INTO FRIDAY WITH MAINLY RAIN AND SNOW SHOWERS
SOUTH AND MIXED PRECIPITATION TRANSITIONING TO SNOW NORTH...AS WELL
AS BLUSTERY AND COLD CONDITIONS TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1100 AM...DROPPED WEATHER ADVISORIES FOR OUR HUDSON VALLEY
FROM THE CAPITAL DISTRICT SOUTHWARD....AS WELL AS WESTERN ULSTER
COUNTY AND NORTHERN LITCHFIELD COUNTY. SOME OF THESE AREAS HAVE BEEN
REPORTING A MIX...BUT WITH TEMPERATURES ABOVE FREEZING...NO MORE
ACCUMULATIONS ARE EXPECTED.
WE KEPT THE WINTER WEATHER ADVISORY UP FOR MOST OF THE THE HIGHER
TERRAIN SURROUNDING THE CAPITAL DISTRICT AS TEMPERATURES WERE STILL
IN SOME CASES...BELOW FREEZING. THE ADVISORY IS MAINLY FOR POCKETS
OF FREEZING. WITH THE EXCEPTION OF THE ADIRONDACKS...ANY ADDITIONAL
ACCUMULATIONS IN THESE AREA OF SNOW WOULD ONLY 1-2 INCHES. THE
ADIRONDACKS COULD SEE UP TO 3 INCHES ADDITIONAL SNOWFALL...BUT MOST
AREAS EVEN THERE WILL CLOSE TO AN INCH.
TEMPERATURES WILL SLOWLY RISE TO AT OR ABOVE FREEZING HIGHER TERRAIN
AND AREA NORTH OF ALBANY...WITH VALLEY AREAS 35 TO 40. SOME AREAS
PRIMED TO DOWNSLOPING WINDS OFF THE HIGHER TERRAIN COULD REACH INTO
THE LOWER 40S.
**********PREVIOUS NEAR TERM DISCUSSION****************
AS OF 830 AM...THE FIRST BIG BATCH OF PRECIPITATION...MAINLY AS SNOW
FROM ALBANY NORTH...MIX FURTHER SOUTH...HAS LIFTED NORTHWARD. THIS
WAS ASSOCIATED WITH THE FRONTOGENETIC FORCING.
ANOTHER BATCH OF PRECIPITATION WAS WORKING UP THE HUDSON
VALLEY...ASSOCIATED WITH THE ACTUAL UPPER LEVEL LOW. WE HONESTLY ARE
NOT SURE WHAT EXACT FORM THIS PRECIPITATION WAS FALLING. SUSPECT
MAINLY RAIN...MIXED WITH POCKETS OF FREEZING RAIN AND SLEET. HOWEVER
IT MOVES NORTHWARD...IT COULD TRANSLATE BACK TO SNOW FROM ALBANY
NORTH BASED ON OUR SOUNDING. WHILE TEMPERATURES AT ALBANY HAVE
SLIPPED ABOVE FREEZING...THE FREEZING LEVEL IS QUITE...ONLY A 1000
FEET OR SO OFF THE GROUND...SO IT WOULDN`T TAKE MUCH MELTING
SNOWFLAKES TO COOL THE COLUMN.
UPDATED FORECAST TO REFLECT CURRENT TRENDS BUT DECIDED TO LEAVE ALL
FLAGS UP FOR NOW. THUS FAR...FREEZING RAIN HAS NOT BE
PREVALENT...BUT MORE OF RAIN/SNOW SITUATION (WITH A LITTLE SLEET AS
WELL).
********PREVIOUS NEAR TERM FORECAST********
AS OF 7 AM EST...995 MB COASTAL LOW WAS LOCATED NEAR CAPE MAY WITH
THE PRIMARY LOW BACK ACROSS NORTHERN OHIO. BULK OF PCPN WITH THE
MAIN SURGE OF PCPN HAS TAPERED OFF FROM THE CAPITAL DISTRICT SOUTH
TEMPORARILY ALTHOUGH NEXT SURGE OF PCPN MAINLY IN THE FORM OF RAIN
ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS MOVING ACROSS
NORTHERN NEW JERSEY AND NORTHEAST PA. WILL LEAVE REMAINING
ADVISORIES IN PLACE FOR NOW AS STILL SOME MIXED PRECIPITATION
FALLING. AREAS TO THE NORTHWEST WHICH ARE STILL BELOW FREEZING
HAVE REPORTED A PROLONGED PERIOD OF SLEET AND FREEZING RAIN
ESPECIALLY ACROSS THE WESTERN MOHAWK VALLEY AND PORTIONS OF THE
WESTERN ADIRONDACKS. HAVE ADJUSTED HOURLY GRIDS TO BETTER FIT
CURRENT OBS AND RADAR TRENDS. ALSO HAVE ADJUSTED QPF...SNOW AND
ICE AMOUNTS SLIGHTLY TO REFLECT LATEST REPORTS AS WELL AS EXPECTED
ADDITIONAL AMOUNTS. BULK OF THE MIXED PCPN IS EXPECTED TO BE OVER
BY THE END OF THE MORNING COMMUTE EXCEPT ACROSS FAR NORTHERN AREAS
AND WILL KEEP ADVISORY UP THROUGH THE AFTERNOON AT THIS TIME FOR
THE SOUTHERN ADIRONDACKS.
AS OF 4 AM EST...995 MB COASTAL LOW HAS MOVED OVER THE DELMARVA
PENINSULA AND IS TRACKING TOWARD LONG ISLAND AS THE PRIMARY LOW TO
THE WEST REMAINS OVER NORTH CENTRAL OHIO. TEMPERATURES HAVE COOLED
ACROSS MOST OF THE CENTRAL PORTION OF THE FA DURING THE LAST FEW
HOURS AS DEWPOINTS HAVE RISEN. FAR NORTHERN PORTIONS OF THE FA
HAVE SEEN TEMPS AND DEWPOINTS RISE WITH FAR SOUTHEAST PORTION OF
FA NOT ABLE TO TAP ENOUGH COLD AIR TO SUPPORT MUCH IN THE WAY OF
MIXED PCPN WITH MOSTLY RAIN OCCURRING. PARTIAL THICKNESS
VALUES...MODEL SOUNDINGS AND HRRR TEMPS ALL SUPPORT A GRADUAL
TRANSITION DURING THE MORNING TO ALL RAIN EXCEPT ACROSS THE
SOUTHERN ADIRONDACKS WHERE A WINTRY MIX WILL CONTINUE INTO THE
AFTERNOON. BEST FRONTOGENESIS IS NOW OCCURRING ACROSS THE
NORTHERN HALF OF FA AND THIS WILL SLIDE NORTH AND EAST OF THE FA
BY 12Z. ALREADY SEEING SOME BREAKS IN THE PCPN OCCURRING ACROSS
FAR SOUTHEAST PORTION OF FA AND EXPECT THAT THIS WILL CAUSE PCPN
TO DIMINISH IN INTENSITY FROM SOUTH TO NORTH OVER THE NEXT SEVERAL
HOURS...ALTHOUGH ONE MORE ROUND OF FAIRLY INTENSE PCPN IS
EXPECTED ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS LATER THIS
MORNING. HAVE ADJUSTED POPS TO REFLECT RADAR TRENDS...PTYPE
ADJUSTED BY PARTIAL THICKNESS VALUES GOING CLOSER TO MAV WITH
FORECAST ESSENTIALLY BACK TO THAT WHICH WAS ISSUED AT 4 AM
YESTERDAY. SNOW AMOUNTS WERE GENERALLY CREATED USING A SNOW TO
LIQUID RATIO OF 6:1. HIGHEST SNOWFALL ACCUMULATIONS WILL BE IN THE
MOUNTAINS WHERE 2 TO 6 INCHES OF SNOW IS EXPECTED...HIGHEST TOTALS
OVER SOUTHERN GREEN MOUNTAINS WITH GENERALLY AN INCH OR TWO IN THE
VALLEYS. ICE ACCRETION WILL GENERALLY BE AN INCH OR LESS EXCEPT UP
TO A QUARTER OF AN INCH IS POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS.
EXPECT TEMPS TO SLOWLY RISE FROM CURRENT VALUES IN THE MID TO
UPPER 20S NORTH AND LOW TO MID 30S SOUTH TO THE LOW TO MID 30S
NORTH AND UPPER 30S TO MID 40S SOUTH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
PSEUDO WARM FRONT LIFTS NORTHWARD THURSDAY EVENING AS MID LEVEL DRY
SLOT ADVANCES NORTHWARD ACROSS THE REGION. BUFR PROFILES DO SUGGEST
AMPLE LOW LEVEL MOISTURE WHICH WILL BE CLOSE TO THE -10C ALOFT FOR
ENOUGH ICE NUCLEI TO WARRANT THE LOW CHANCE POPS FOR THE REGION
OVERNIGHT. MAIN DYNAMICS WITH OHIO VALLEY SYSTEM BEGINS TO ENCROACH
OUR WESTERN ZONES WELL AFTER MIDNIGHT WHERE WE WILL INCREASE POPS.
THERMAL PROFILES WILL REMAIN A CHALLENGE...ESPECIALLY FOR PORTIONS
OF THE MOHAWK VALLEY AND DACKS WHERE SURFACE TEMPERATURES ARE
EXPECTED TO DROP BACK INTO THE UPPER 20S AND LOWER 30S. THIS POSES
A PROBLEM WITH THE CHANCE FOR FREEZING RAIN/DRIZZLE DUE TO THE
AFOREMENTIONED POTENTIAL LACK OF ICE NUCLEI.
POTENT MID LEVEL JET COINCIDING WITH IMPRESSIVE FRONTOGENESIS WILL
MAKE FOR AN INTERESTING WEATHER ON FRIDAY MORNING. QG DIAGNOSTIC
FIELDS ARE IMPRESSIVE WITH RAPIDLY INCREASING VERTICAL VELOCITIES
OVER THE CWA AND STEEPENING MID LEVEL LAPSE RATES. WOULD NOT BE
SURPRISED TO FIND A FEW SQUALLS EMBEDDED ALONG THE ARCTIC COLD FRONT
THAT WILL MOVE EAST OF THE CWA BY LATE MORNING FRIDAY /AS SUGGESTED
IN THE EXPERIENTIAL HIRES WINDOWS OF MESOSCALE MODELS/. IN
FACT...TEMPERATURES IN THE WAKE OF THE FROPA SHOULD DROP BACK BELOW
FREEZING WHICH COULD RESULT IN BLACK ICE FORMATION WHERE SURFACES
ARE NOT TREATED. LINGERING SURFACE TROUGH AXIS AND DEFORMATION
DYNAMICS OVER WESTERN AND EASTERN NY COULD PROLONG THE SNOWFALL
WHICH WILL BE MONITORED CLOSELY. FURTHERMORE...LAKE ONTARIO
CONTRIBUTION IS EXPECTED TO INCREASE FRIDAY AFTERNOON INTO FRIDAY
NIGHT WITH A 270-280 WIND DIRECTION AND INCREASING LAKE DELTA T/S.
SEVERAL INCHES OF SNOW /AND BLOWING SNOW/ ARE POSSIBLE FOR PORTIONS
OF THE MOHAWK VALLEY...SOUTHERN DACKS. DUE TO FORECAST CHALLENGES
THAT REMAIN WITH RESPECT TO THE WIND TRAJECTORIES AND THE TIMING OF
THE INVERSION LEVELS DROPPING BELOW 5K FEET...WE WILL NOT HOIST ANY
HEADLINES AT THE PRESENT TIME. WE WILL HIGHLIGHT IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVER THE WEEKEND...THE NORTHEAST WILL BE DOMINATED BY A LARGE SCALE
TROUGH. THIS WILL KEEP TEMPS A LITTLE COOLER THAN THEY HAVE BEEN
RECENTLY AND SOMEWHAT BELOW NORMAL. HOWEVER...IT WON/T BE BRUTALLY
COLD BY ANY STRETCH. THE 12 UTC GEFS IS SHOWING 850 HPA TEMPS
GENERALLY NEAR NORMAL...WITH A BRIEF PERIOD OF ABOUT 1-2 STD BELOW
NORMAL. THE LATEST DETERMINISTIC 12 UTC GFS IS SHOWING 850 HPA
TEMPS OF AROUND -15 DEGREES C FOR SATURDAY...AND -16 TO -18 DEGREES
ON SUNDAY. THIS WILL TRANSLATE TO MAX TEMPS IN THE 20S TO LOW 30S ON
SATURDAY...AND MAX TEMPS IN THE TEENS TO LOW 20S FOR SUNDAY. MIN
TEMPS ON SAT AND SUN NIGHTS WILL GENERALLY BE IN THE SINGLE
DIGITS...WITH BELOW ZERO READINGS ACROSS THE HIGH TERRAIN. WHILE
THIS WILL PROBABLY WIND UP BEING SOME OF THE COLDER NIGHTS OF THE
SEASON SO FAR...IT/S STILL NOT FAR FROM WHAT IS CONSIDERED NORMAL OR
EXPECTED FOR THIS TIME OF THE YEAR.
IT WILL REMAIN FAIRLY DRY OVER THE WEEKEND. THE CYCLONIC FLOW MAY
ALLOW FOR SOME CLOUDS...ESP IN AREAS DOWNWIND OF LAKE ONTARIO.
HOWEVER...THE FLOW WON/T BE OVERLY CONDUCIVE FOR LAKE EFFECT...AND
INVERSION HEIGHTS OF ONLY AROUND 1 KM WILL KEEP ANY LAKE EFFECT SNOW
SHOWERS AS FAIRLY LIGHT AND CONFINED CLOSE TO THE LAKE SHORE. WILL
ONLY ALLOW A BRIEF PERIOD CHC POPS FOR PARTS OF THE MOHAWK
VALLEY/SCHOHARIE COUNTY FOR SAT MORNING...BEFORE LOWERING POPS TO
SLIGHT CHC FOR THE REMAINDER OF SATURDAY.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR MONDAY. THIS WILL
CONTINUE THE DRY WEATHER. TEMPS WILL CONTINUE TO BE A LITTLE ON THE
COOL SIDE...BUT NOTHING UNHEARD OF FOR MID JANUARY...WITH 20S FOR
MOST AREAS. SOME CLOUDS WILL BEGIN TO INCREASE FOR MONDAY NIGHT
AHEAD OF AN APPROACHING STORM SYSTEM. MIN TEMPS MAY ACTUALLY WIND
UP BEING EARLIER IN THE NIGHT...AS TEMPS MAY SLOWLY RISE OVERNIGHT
WITH AN INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW. FOR NOW...HAVE
GONE WITH MIN TEMPS IN THE TEENS IN MOST AREAS.
A STRENGTHENING LOW PRESSURE AREA WILL RACE FROM THE UPPER GREAT
LAKES TOWARDS NORTHERN QUEBEC ON TUESDAY. AN ARCTIC FRONT ASSOCIATED
WITH THIS STORM SYSTEM WILL SWING THROUGH OUR AREA ON TUESDAY. THIS
WILL ALLOW FOR SOME RAIN/SNOW SHOWERS...WITH P-TYPE DEPENDENT ON
ELEVATION/BOUNDARY LAYER TEMPS. MOST VALLEY AREAS WILL PROBABLY WARM
UP JUST ENOUGH TO KEEP MOST OF THE PRECIP AS RAIN...ESP CONSIDERING
THIS STORM IS COMING FROM THE WEST WITH A STORM SYSTEM TRACKING WELL
NORTH OF THE AREA. TEMPS LOOK TO REACH THE 30S IN VALLEY
AREAS...WITH MAX TEMPS IN THE UPPER 20S TO NEAR FREEZING IN THE HIGH
TERRAIN. PRECIP WILL BE SHOWERY IN NATURE AND QPF WILL BE RATHER
LIGHT...WITH LESS THAN A QUARTER OF AN INCH IN MOST AREAS.
IN THE WAKE OF THIS SYSTEM...COOLER AIR WILL AGAIN FILTER INTO THE
REGION FOR TUESDAY NIGHT INTO WEDNESDAY. SOME LAKE EFFECT COULD
AFFECT FAR WESTERN AREAS. TEMPS LOOK TO GO BACK BELOW NORMAL FOR
WEDNESDAY...WITH MAINLY TEENS AND 20S FOR MAX TEMPS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
LOW CONFIDENCE FORECAST FOR MAINLY THE TONIGHT PERIOD.
THE STORM THAT IMPACTED THE TAFS EARLIER...WAS PULLING AWAY TO THE
EAST OF LONG ISLAND. IN ITS WAKE...LOTS OF MVFR CLOUDS WILL PERSIST.
THEN...ANOTHER DISTURBANCE AND COLD FRONT WILL APPROACH THE TAF
SITES ON FRIDAY...BRINGING MUCH COLDER AIR BEHIND IT.
THE BULK OF THE PRECIPITATION ASSOCIATED WITH THE STORM...IS
FINISHED. THERE MIGHT BE SOME OCCASIONAL DRIZZLE BUT THAT SHOULD BE
MAINLY IT THROUGH THIS EVENING. WILL CONTINUE WITH THE VCSH TO
REFLECT THE POSSIBILITY OF SHOWERS THROUGH THE EVENING.
SHOWERS WILL BREAK OUT LATER OVERNIGHT INTO FRIDAY...MIXING WITH
SNOW BY MIDDAY AT ALL TAF SITES.
THE PROBLEM TONIGHT IS RIGHT NOW WE ARE ASSUMING THE CLOUDS WILL
HOLD. IF THEY DO...ALL THE TAFS WILL LIKELY HAVE MVFR CONDITIONS
(MAINLY CIG...AOB 2000 FEET). HOWEVER...IF THE CLOUDS WERE TO THIN
OR EVEN CLEAR OUT (WHICH WE LEAN AGAINST BUT CERTAINLY
POSSIBLE)...SOME IFR FOG IS POSSIBLE...ESPECIALLY AT KGFL. THE WIND
ALOFT LOOKS REMAIN 30KTS OR HIGHER (WELL OFF THE DECK) WHICH SHOULD
HELP MITIGATE THE FORMATION OF IFR FOG. FOR NOW...NO MENTION OF IFR
UNTIL THE SHOWERS BEGIN TURNING TO SNOW...WHICH LOOKS TO BE AROUND
15Z FRIDAY. HOWEVER...IF THE FRONT MOVES IN FASTER...THE CHANGEOVER
COULD EVEN BE A LITTLE QUICKER.
THE NORTHERLY WIND 5-10 KTS WILL TURN SOUTHERLY LATER TOWARD
EVENING. THEY WILL TEND TO INCREASE A LITTLE OVERNIGHT...ESPECIALLY
AT KALB. THEN...THEY WILL SHIFT INTO THE WEST OR SOUTHWEST...AND
BECOME GUSTY AT KALB.
NOT SHOWN IN THE TAFS IS THAT THE WIND LOOKS TO BECOME STRONG AT ALL
THE TAF SITES BY LATER FRIDAY AFTERNOON...POSSIBLY GUSTING TO OVER
30KTS...ESPECIALLY AT KALB. THERE MIGHT ALSO BE INTENSE SNOW SQUALLS
BRIEFLY REDUCING VISIBILITY TO WELL UNDER A MILE.
BEST TO CHECK IN WITH THE FORECAST/DISCUSSION FOR LATER UPDATES.
OUTLOOK...
FRI NT...MAINLY VFR...WINDY. CHC MVFR -SHSN.
SUN-MON...VFR...NO SIG WX.
TUE...VFR...CHC MVFR -RASN.
&&
.HYDROLOGY...
A COMPLEX STORM SYSTEM CURRENTLY IMPACTING THE FA WILL CONTINUE TO
BRING MIX PRECIPITATION TO THE HYDROLOGIC SERVICE AREA THIS MORNING
TRANSITIONING TO ALL RAIN...ESPECIALLY SOUTH AND EAST OF THE SOUTHERN
ADIRONDACKS BY THE AFTERNOON. THE PRECIPITATION WILL BE ASSOCIATED
WITH A COASTAL OR SECONDARY LOW THAT WILL MOVE NORTHEAST OF LONG
ISLAND BY THIS AFTERNOON. THE PRIMARY LOW WILL REMAIN TO THE WEST
OVER THE OHIO VALLEY AND THE GREAT LAKES REGION. TOTAL LIQUID
EQUIVALENT VALUES WILL RANGE FROM A HALF AN INCH TO AROUND AN INCH
BY THURSDAY EVENING. WE ARE EXPECTING SOME DOWNSLOPING TO REDUCE
TOTAL QPF AMOUNTS TO AROUND A HALF AN INCH TO TWO THIRDS OF AN INCH
IN THE UPPER HUDSON VALLEY...AND PORTIONS OF THE LAKE GEORGE REGION.
THE HEAVIEST QPF WILL TEND TO BE SOUTH AND WEST OF THE CAPITAL
REGION. WE ARE EXPECTING MINIMAL IMPACT ON THE MAIN STEM RIVERS WITH
SOME MINOR RISES AT BEST. MOST OF THE PRECIPITATION WILL FALL AS
SNOW...SLEET AND FREEZING RAIN OVER THE NORTHERN BASINS.
TONIGHT...A BRIEF LULL WILL OCCUR BETWEEN THE SYSTEMS...WITH A
DRY SLOT. THERE MIGHT BE SOME SPOTTY FREEZING RAIN OR DRIZZLE
NORTH AND WEST OF THE CAPITAL REGION WITH SPOTTY PLAIN RAIN SOUTH
AND EAST. THE NEXT STRONG UPPER LEVEL DISTURBANCE WILL BRING RAIN
AND SNOW SHOWERS ON FRIDAY....AS IT MOVES OVER UPSTATE NY. THERE
COULD EVEN BE A FEW INTENSE SNOW SQUALLS. TOTAL QPF FROM THIS
SYSTEM LOOKS LIKE TWO TENTHS OF AN INCH SOUTHEAST TO TWO THIRDS OF
AN INCH NORTHWEST. COLDER AIR AND LAKE EFFECT SNOW SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO THE WEEKEND.
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 6 PM EST THIS EVENING FOR NYZ032-
033-042-043-082.
MA...NONE.
VT...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR
VTZ013>015.
&&
$$
SYNOPSIS...HWJIV/11/NAS
NEAR TERM...HWJIV/11
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
1105 AM EST THU JAN 12 2012
.SYNOPSIS...
LOW PRESSURE SOUTH OF LONG ISLAND WILL DRIFT TO OUR EAST THIS
AFTERNOON. ANOTHER LOW PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE
OHIO VALLEY TONIGHT INTO FRIDAY WITH MAINLY RAIN AND SNOW SHOWERS
SOUTH AND MIXED PRECIPITATION TRANSITIONING TO SNOW NORTH...AS WELL
AS BLUSTERY AND COLD CONDITIONS TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1100 AM...DROPPED WEATHER ADVISORIES FOR OUR HUDSON VALLEY
FROM THE CAPITAL DISTRICT SOUTHWARD....AS WELL AS WESTERN ULSTER
COUNTY AND NORTHERN LITCHFIELD COUNTY. SOME OF THESE AREAS HAVE BEEN
REPORTING A MIX...BUT WITH TEMPERATURES ABOVE FREEZING...NO MORE
ACCUMULATIONS ARE EXPECTED.
WE KEPT THE WINTER WEATHER ADVISORY UP FOR MOST OF THE THE HIGHER
TERRAIN SURROUNDING THE CAPITAL DISTRICT AS TEMPERATURES WERE STILL
IN SOME CASES...BELOW FREEZING. THE ADVISORY IS MAINLY FOR POCKETS
OF FREEZING. WITH THE EXCEPTION OF THE ADIRONDACKS...ANY ADDITIONAL
ACCUMULATIONS IN THESE AREA OF SNOW WOULD ONLY 1-2 INCHES. THE
ADIRONDACKS COULD SEE UP TO 3 INCHES ADDITIONAL SNOWFALL...BUT MOST
AREAS EVEN THERE WILL CLOSE TO AN INCH.
TEMPERATURES WILL SLOWLY RISE TO AT OR ABOVE FREEZING HIGHER TERRAIN
AND AREA NORTH OF ALBANY...WITH VALLEY AREAS 35 TO 40. SOME AREAS
PRIMED TO DOWNSLOPING WINDS OFF THE HIGHER TERRAIN COULD REACH INTO
THE LOWER 40S.
**********PREVIOUS NEAR TERM DISCUSSION****************
AS OF 830 AM...THE FIRST BIG BATCH OF PRECIPITATION...MAINLY AS SNOW
FROM ALBANY NORTH...MIX FURTHER SOUTH...HAS LIFTED NORTHWARD. THIS
WAS ASSOCIATED WITH THE FRONTOGENETIC FORCING.
ANOTHER BATCH OF PRECIPITATION WAS WORKING UP THE HUDSON
VALLEY...ASSOCIATED WITH THE ACTUAL UPPER LEVEL LOW. WE HONESTLY ARE
NOT SURE WHAT EXACT FORM THIS PRECIPITATION WAS FALLING. SUSPECT
MAINLY RAIN...MIXED WITH POCKETS OF FREEZING RAIN AND SLEET. HOWEVER
IT MOVES NORTHWARD...IT COULD TRANSLATE BACK TO SNOW FROM ALBANY
NORTH BASED ON OUR SOUNDING. WHILE TEMPERATURES AT ALBANY HAVE
SLIPPED ABOVE FREEZING...THE FREEZING LEVEL IS QUITE...ONLY A 1000
FEET OR SO OFF THE GROUND...SO IT WOULDN`T TAKE MUCH MELTING
SNOWFLAKES TO COOL THE COLUMN.
UPDATED FORECAST TO REFLECT CURRENT TRENDS BUT DECIDED TO LEAVE ALL
FLAGS UP FOR NOW. THUS FAR...FREEZING RAIN HAS NOT BE
PREVALENT...BUT MORE OF RAIN/SNOW SITUATION (WITH A LITTLE SLEET AS
WELL).
********PREVIOUS NEAR TERM FORECAST********
AS OF 7 AM EST...995 MB COASTAL LOW WAS LOCATED NEAR CAPE MAY WITH
THE PRIMARY LOW BACK ACROSS NORTHERN OHIO. BULK OF PCPN WITH THE
MAIN SURGE OF PCPN HAS TAPERED OFF FROM THE CAPITAL DISTRICT SOUTH
TEMPORARILY ALTHOUGH NEXT SURGE OF PCPN MAINLY IN THE FORM OF RAIN
ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS MOVING ACROSS
NORTHERN NEW JERSEY AND NORTHEAST PA. WILL LEAVE REMAINING
ADVISORIES IN PLACE FOR NOW AS STILL SOME MIXED PRECIPITATION
FALLING. AREAS TO THE NORTHWEST WHICH ARE STILL BELOW FREEZING
HAVE REPORTED A PROLONGED PERIOD OF SLEET AND FREEZING RAIN
ESPECIALLY ACROSS THE WESTERN MOHAWK VALLEY AND PORTIONS OF THE
WESTERN ADIRONDACKS. HAVE ADJUSTED HOURLY GRIDS TO BETTER FIT
CURRENT OBS AND RADAR TRENDS. ALSO HAVE ADJUSTED QPF...SNOW AND
ICE AMOUNTS SLIGHTLY TO REFLECT LATEST REPORTS AS WELL AS EXPECTED
ADDITIONAL AMOUNTS. BULK OF THE MIXED PCPN IS EXPECTED TO BE OVER
BY THE END OF THE MORNING COMMUTE EXCEPT ACROSS FAR NORTHERN AREAS
AND WILL KEEP ADVISORY UP THROUGH THE AFTERNOON AT THIS TIME FOR
THE SOUTHERN ADIRONDACKS.
AS OF 4 AM EST...995 MB COASTAL LOW HAS MOVED OVER THE DELMARVA
PENINSULA AND IS TRACKING TOWARD LONG ISLAND AS THE PRIMARY LOW TO
THE WEST REMAINS OVER NORTH CENTRAL OHIO. TEMPERATURES HAVE COOLED
ACROSS MOST OF THE CENTRAL PORTION OF THE FA DURING THE LAST FEW
HOURS AS DEWPOINTS HAVE RISEN. FAR NORTHERN PORTIONS OF THE FA
HAVE SEEN TEMPS AND DEWPOINTS RISE WITH FAR SOUTHEAST PORTION OF
FA NOT ABLE TO TAP ENOUGH COLD AIR TO SUPPORT MUCH IN THE WAY OF
MIXED PCPN WITH MOSTLY RAIN OCCURRING. PARTIAL THICKNESS
VALUES...MODEL SOUNDINGS AND HRRR TEMPS ALL SUPPORT A GRADUAL
TRANSITION DURING THE MORNING TO ALL RAIN EXCEPT ACROSS THE
SOUTHERN ADIRONDACKS WHERE A WINTRY MIX WILL CONTINUE INTO THE
AFTERNOON. BEST FRONTOGENESIS IS NOW OCCURRING ACROSS THE
NORTHERN HALF OF FA AND THIS WILL SLIDE NORTH AND EAST OF THE FA
BY 12Z. ALREADY SEEING SOME BREAKS IN THE PCPN OCCURRING ACROSS
FAR SOUTHEAST PORTION OF FA AND EXPECT THAT THIS WILL CAUSE PCPN
TO DIMINISH IN INTENSITY FROM SOUTH TO NORTH OVER THE NEXT SEVERAL
HOURS...ALTHOUGH ONE MORE ROUND OF FAIRLY INTENSE PCPN IS
EXPECTED ASSOCIATED WITH THE UPPER TROUGH AND VORT AXIS LATER THIS
MORNING. HAVE ADJUSTED POPS TO REFLECT RADAR TRENDS...PTYPE
ADJUSTED BY PARTIAL THICKNESS VALUES GOING CLOSER TO MAV WITH
FORECAST ESSENTIALLY BACK TO THAT WHICH WAS ISSUED AT 4 AM
YESTERDAY. SNOW AMOUNTS WERE GENERALLY CREATED USING A SNOW TO
LIQUID RATIO OF 6:1. HIGHEST SNOWFALL ACCUMULATIONS WILL BE IN THE
MOUNTAINS WHERE 2 TO 6 INCHES OF SNOW IS EXPECTED...HIGHEST TOTALS
OVER SOUTHERN GREEN MOUNTAINS WITH GENERALLY AN INCH OR TWO IN THE
VALLEYS. ICE ACCRETION WILL GENERALLY BE AN INCH OR LESS EXCEPT UP
TO A QUARTER OF AN INCH IS POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS.
EXPECT TEMPS TO SLOWLY RISE FROM CURRENT VALUES IN THE MID TO
UPPER 20S NORTH AND LOW TO MID 30S SOUTH TO THE LOW TO MID 30S
NORTH AND UPPER 30S TO MID 40S SOUTH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
PSEUDO WARM FRONT LIFTS NORTHWARD THURSDAY EVENING AS MID LEVEL DRY
SLOT ADVANCES NORTHWARD ACROSS THE REGION. BUFR PROFILES DO SUGGEST
AMPLE LOW LEVEL MOISTURE WHICH WILL BE CLOSE TO THE -10C ALOFT FOR
ENOUGH ICE NUCLEI TO WARRANT THE LOW CHANCE POPS FOR THE REGION
OVERNIGHT. MAIN DYNAMICS WITH OHIO VALLEY SYSTEM BEGINS TO ENCROACH
OUR WESTERN ZONES WELL AFTER MIDNIGHT WHERE WE WILL INCREASE POPS.
THERMAL PROFILES WILL REMAIN A CHALLENGE...ESPECIALLY FOR PORTIONS
OF THE MOHAWK VALLEY AND DACKS WHERE SURFACE TEMPERATURES ARE
EXPECTED TO DROP BACK INTO THE UPPER 20S AND LOWER 30S. THIS POSES
A PROBLEM WITH THE CHANCE FOR FREEZING RAIN/DRIZZLE DUE TO THE
AFOREMENTIONED POTENTIAL LACK OF ICE NUCLEI.
POTENT MID LEVEL JET COINCIDING WITH IMPRESSIVE FRONTOGENESIS WILL
MAKE FOR AN INTERESTING WEATHER ON FRIDAY MORNING. QG DIAGNOSTIC
FIELDS ARE IMPRESSIVE WITH RAPIDLY INCREASING VERTICAL VELOCITIES
OVER THE CWA AND STEEPENING MID LEVEL LAPSE RATES. WOULD NOT BE
SURPRISED TO FIND A FEW SQUALLS EMBEDDED ALONG THE ARCTIC COLD FRONT
THAT WILL MOVE EAST OF THE CWA BY LATE MORNING FRIDAY /AS SUGGESTED
IN THE EXPERIENTIAL HIRES WINDOWS OF MESOSCALE MODELS/. IN
FACT...TEMPERATURES IN THE WAKE OF THE FROPA SHOULD DROP BACK BELOW
FREEZING WHICH COULD RESULT IN BLACK ICE FORMATION WHERE SURFACES
ARE NOT TREATED. LINGERING SURFACE TROUGH AXIS AND DEFORMATION
DYNAMICS OVER WESTERN AND EASTERN NY COULD PROLONG THE SNOWFALL
WHICH WILL BE MONITORED CLOSELY. FURTHERMORE...LAKE ONTARIO
CONTRIBUTION IS EXPECTED TO INCREASE FRIDAY AFTERNOON INTO FRIDAY
NIGHT WITH A 270-280 WIND DIRECTION AND INCREASING LAKE DELTA T/S.
SEVERAL INCHES OF SNOW /AND BLOWING SNOW/ ARE POSSIBLE FOR PORTIONS
OF THE MOHAWK VALLEY...SOUTHERN DACKS. DUE TO FORECAST CHALLENGES
THAT REMAIN WITH RESPECT TO THE WIND TRAJECTORIES AND THE TIMING OF
THE INVERSION LEVELS DROPPING BELOW 5K FEET...WE WILL NOT HOIST ANY
HEADLINES AT THE PRESENT TIME. WE WILL HIGHLIGHT IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVER THE WEEKEND...THE NORTHEAST WILL BE DOMINATED BY A LARGE SCALE
TROUGH. THIS WILL KEEP TEMPS A LITTLE COOLER THAN THEY HAVE BEEN
RECENTLY AND SOMEWHAT BELOW NORMAL. HOWEVER...IT WON/T BE BRUTALLY
COLD BY ANY STRETCH. THE 12 UTC GEFS IS SHOWING 850 HPA TEMPS
GENERALLY NEAR NORMAL...WITH A BRIEF PERIOD OF ABOUT 1-2 STD BELOW
NORMAL. THE LATEST DETERMINISTIC 12 UTC GFS IS SHOWING 850 HPA
TEMPS OF AROUND -15 DEGREES C FOR SATURDAY...AND -16 TO -18 DEGREES
ON SUNDAY. THIS WILL TRANSLATE TO MAX TEMPS IN THE 20S TO LOW 30S ON
SATURDAY...AND MAX TEMPS IN THE TEENS TO LOW 20S FOR SUNDAY. MIN
TEMPS ON SAT AND SUN NIGHTS WILL GENERALLY BE IN THE SINGLE
DIGITS...WITH BELOW ZERO READINGS ACROSS THE HIGH TERRAIN. WHILE
THIS WILL PROBABLY WIND UP BEING SOME OF THE COLDER NIGHTS OF THE
SEASON SO FAR...IT/S STILL NOT FAR FROM WHAT IS CONSIDERED NORMAL OR
EXPECTED FOR THIS TIME OF THE YEAR.
IT WILL REMAIN FAIRLY DRY OVER THE WEEKEND. THE CYCLONIC FLOW MAY
ALLOW FOR SOME CLOUDS...ESP IN AREAS DOWNWIND OF LAKE ONTARIO.
HOWEVER...THE FLOW WON/T BE OVERLY CONDUCIVE FOR LAKE EFFECT...AND
INVERSION HEIGHTS OF ONLY AROUND 1 KM WILL KEEP ANY LAKE EFFECT SNOW
SHOWERS AS FAIRLY LIGHT AND CONFINED CLOSE TO THE LAKE SHORE. WILL
ONLY ALLOW A BRIEF PERIOD CHC POPS FOR PARTS OF THE MOHAWK
VALLEY/SCHOHARIE COUNTY FOR SAT MORNING...BEFORE LOWERING POPS TO
SLIGHT CHC FOR THE REMAINDER OF SATURDAY.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR MONDAY. THIS WILL
CONTINUE THE DRY WEATHER. TEMPS WILL CONTINUE TO BE A LITTLE ON THE
COOL SIDE...BUT NOTHING UNHEARD OF FOR MID JANUARY...WITH 20S FOR
MOST AREAS. SOME CLOUDS WILL BEGIN TO INCREASE FOR MONDAY NIGHT
AHEAD OF AN APPROACHING STORM SYSTEM. MIN TEMPS MAY ACTUALLY WIND
UP BEING EARLIER IN THE NIGHT...AS TEMPS MAY SLOWLY RISE OVERNIGHT
WITH AN INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW. FOR NOW...HAVE
GONE WITH MIN TEMPS IN THE TEENS IN MOST AREAS.
A STRENGTHENING LOW PRESSURE AREA WILL RACE FROM THE UPPER GREAT
LAKES TOWARDS NORTHERN QUEBEC ON TUESDAY. AN ARCTIC FRONT ASSOCIATED
WITH THIS STORM SYSTEM WILL SWING THROUGH OUR AREA ON TUESDAY. THIS
WILL ALLOW FOR SOME RAIN/SNOW SHOWERS...WITH P-TYPE DEPENDENT ON
ELEVATION/BOUNDARY LAYER TEMPS. MOST VALLEY AREAS WILL PROBABLY WARM
UP JUST ENOUGH TO KEEP MOST OF THE PRECIP AS RAIN...ESP CONSIDERING
THIS STORM IS COMING FROM THE WEST WITH A STORM SYSTEM TRACKING WELL
NORTH OF THE AREA. TEMPS LOOK TO REACH THE 30S IN VALLEY
AREAS...WITH MAX TEMPS IN THE UPPER 20S TO NEAR FREEZING IN THE HIGH
TERRAIN. PRECIP WILL BE SHOWERY IN NATURE AND QPF WILL BE RATHER
LIGHT...WITH LESS THAN A QUARTER OF AN INCH IN MOST AREAS.
IN THE WAKE OF THIS SYSTEM...COOLER AIR WILL AGAIN FILTER INTO THE
REGION FOR TUESDAY NIGHT INTO WEDNESDAY. SOME LAKE EFFECT COULD
AFFECT FAR WESTERN AREAS. TEMPS LOOK TO GO BACK BELOW NORMAL FOR
WEDNESDAY...WITH MAINLY TEENS AND 20S FOR MAX TEMPS.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
AS OF 800 AM...THE HEAVIEST PRECIPITATION HAS MOVED NORTH OF THE
TERMINALS. HOWEVER...THERE ARE MORE SHOWERS OF MAINLY RAIN WORKING
TOWARD KPOU.
REMOVED LLWS FROM KPOU SINCE THEY ARE REPORTING WIND GUSTS TO NEAR
20KTS AND THE ALY RAOB INDICATED THE WIND AT 2000 FEET AROUND 35KT
(NOT 45KTS). NARROWED THE TIME OF LLWS FROM MID TO LATER MORNING AT
KALB AND KGFL AS THAT IS WHEN THE STRONGEST WIND ALOFT MOVE THROUGH.
ALSO REMOVED ANY MENTION OF FREEZING RAIN FROM KGFL.
IFR/MVFR STRADDLE AT BOTH KALB AND KGFL BUT AS PCPN CHANGES TO RAIN
MVFR CONDITIONS WILL PREVAIL. WILL KEEP CIGS PREVAILING AT 2000 FEET
OR LESS ALTHOUGH WITH A DOWNSLOPING WIND...EVEN THESE MIGHT
OCCASIONALLY RISE UP TO VFR AS THEY DID AT KALB JUST BEFORE 800 AM.
OUR INCOMING 12Z RAOB STILL INDICATED A PRETTY STRONG ESE WIND OFF
THE DECK AT AROUND 1500 FEET. HOWEVER...IT MIGHT BE QUITE A STRONG
AS FORECASTED BY THE MODELS. WE WILL REVIEW THE LOW LEVEL WIND SHEAR
ASPECT WHEN THE ENTIRE RAOB COMES THROUGH. FOR NOW...CONTINUE WITH
LOW LEVEL WIND SHEAR UP TO 2000 FEET WITH AN E OR ESE WIND AROUND
40/45KTS THROUGH MUCH OF THE MORNING.
EVEN AFTER THE SYSTEM PASSED BY LATER TODAY...WE SHOULD HOLD ONTO
MVFR CLOUDS THROUGH MUCH OF THE NIGHT. AS LONG THAT HAPPENS...ANY
IFR FOG SHOULD BE LIMITED. HOWEVER...CONFIDENCE IN THIS THINKING IS
ONLY MODERATE...SO THIS PORTION OF THE TAF COULD CHANGE WITH
TIME.
ANOTHER UPPER LEVEL DISTURBANCE AND COLD FRONT WILL LIKELY BRING
ANOTHER ROUND OF RAIN SHOWERS ON FRIDAY...SWITCHING TO SNOW SHOWERS
AS THE DAY WEARS ON. THE WIND WILL PICK UP FROM THE WEST AND THERE
COULD EVEN BE SOME MORE INTENSE SNOW SQUALLS.
OUTLOOK...
FRI-FRI NT...MVFR/IFR...RAIN OR MIXED PRECIPITATION ENDING AS
SNOW. BECOMING WINDY.
SAT-MON...VFR...NO SIG WX.
&&
.HYDROLOGY...
A COMPLEX STORM SYSTEM CURRENTLY IMPACTING THE FA WILL CONTINUE TO
BRING MIX PRECIPITATION TO THE HYDROLOGIC SERVICE AREA THIS MORNING
TRANSITIONING TO ALL RAIN...ESPECIALLY SOUTH AND EAST OF THE SOUTHERN
ADIRONDACKS BY THE AFTERNOON. THE PRECIPITATION WILL BE ASSOCIATED
WITH A COASTAL OR SECONDARY LOW THAT WILL MOVE NORTHEAST OF LONG
ISLAND BY THIS AFTERNOON. THE PRIMARY LOW WILL REMAIN TO THE WEST
OVER THE OHIO VALLEY AND THE GREAT LAKES REGION. TOTAL LIQUID
EQUIVALENT VALUES WILL RANGE FROM A HALF AN INCH TO AROUND AN INCH
BY THURSDAY EVENING. WE ARE EXPECTING SOME DOWNSLOPING TO REDUCE
TOTAL QPF AMOUNTS TO AROUND A HALF AN INCH TO TWO THIRDS OF AN INCH
IN THE UPPER HUDSON VALLEY...AND PORTIONS OF THE LAKE GEORGE REGION.
THE HEAVIEST QPF WILL TEND TO BE SOUTH AND WEST OF THE CAPITAL
REGION. WE ARE EXPECTING MINIMAL IMPACT ON THE MAIN STEM RIVERS WITH
SOME MINOR RISES AT BEST. MOST OF THE PRECIPITATION WILL FALL AS
SNOW...SLEET AND FREEZING RAIN OVER THE NORTHERN BASINS.
TONIGHT...A BRIEF LULL WILL OCCUR BETWEEN THE SYSTEMS...WITH A
DRY SLOT. THERE MIGHT BE SOME SPOTTY FREEZING RAIN OR DRIZZLE
NORTH AND WEST OF THE CAPITAL REGION WITH SPOTTY PLAIN RAIN SOUTH
AND EAST. THE NEXT STRONG UPPER LEVEL DISTURBANCE WILL BRING RAIN
AND SNOW SHOWERS ON FRIDAY....AS IT MOVES OVER UPSTATE NY. THERE
COULD EVEN BE A FEW INTENSE SNOW SQUALLS. TOTAL QPF FROM THIS
SYSTEM LOOKS LIKE TWO TENTHS OF AN INCH SOUTHEAST TO TWO THIRDS OF
AN INCH NORTHWEST. COLDER AIR AND LAKE EFFECT SNOW SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO THE WEEKEND.
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 NOON EST TODAY FOR NYZ038>041-
043-047-048-051-082>084.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ032-
033-042.
MA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
WIND ADVISORY UNTIL NOON EST TODAY FOR MAZ001.
VT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
WIND ADVISORY UNTIL NOON EST TODAY FOR VTZ013-014.
&&
$$
SYNOPSIS...HWJIV/11/NAS
NEAR TERM...HWJIV/11
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1107 AM EST THU JAN 12 2012
.SYNOPSIS...
A STORM SYSTEM FROM THE OHIO VALLEY TO THE SOUTHERN NEW ENGLAND
COAST WILL MOVE SLOWLY TO THE NORTH AND EAST THROUGH FRIDAY. A
STRONG COLD FRONT WILL MOVE ACROSS THE REGION EARLY FRIDAY
MORNING. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING LOW THROUGH
THE WEEKEND. HIGH PRESSURE REMAINS INTO THE BEGINNING OF THE WEEK.
ANOTHER COLD FRONT MOVES THROUGH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GREATEST PRESSURE FALLS WERE JUST OFF THE SE NEW ENGLAND COAST
LATE THIS MORNING. THIS WOULD SUPPORT THE COASTAL LOW TO THE
SOUTH OF LI TAKING A TRACK TO THE E/SE OF THE TRI-STATE AREA.
12Z NAM AND RUC SUPPORT SUCH A TRACK. THIS WILL IN PART PRODUCE
SOMEWHAT COOLER HIGHS TODAY...ESPECIALLY ACROSS THE INTERIOR...BUT
ALSO KEEP THE WINDS IN A MORE NORTHERLY DIRECTION. IN ADDITION...A
STRONG NE FLOW CONTINUES ACROSS COASTAL LOCATIONS THIS MORNING WITH
GUSTS UP TO 30 MPH. THE GRADIENT WILL SLACKEN BY THIS AFTERNOON AS
THE LOW TRACKS TO THE NE OF THE AREA. MORE IMPORTANTLY...THIS MAY
EXACERBATE COASTAL FLOODING ACROSS LI SOUND THIS AFTERNOON. REFER
TO THE COASTAL FLOOD SECTION BELOW.
AS FOR THE RAIN AND EMBEDDED THUNDERSTORMS...THE MAIN AREA ACROSS
EASTERN CT AND EASTERN LI WILL LIFT TO THE NE AND CLEAR THE AREA
BY NOONTIME. THERE MAY BE PATCHES OF LIGHT RAIN THROUGH THE
AFTERNOON WITH WEAK LIFT AND MOISTURE IN PLACE.
DUE TO THE LOW TRACK...HIGHS WERE ADJUSTED DOWNWARD SEVERAL
DEGREES...MAINLY ACROSS THE INTERIOR. HIGHS MAY NOT GET OUT OF
THE UPPER 30S WELL INLAND. ELSEWHERE...TEMPS SHOULD HOLD STEADY
OR SLIGHTLY FALL FROM THEIR CURRENT READINGS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
NEXT UPPER TROUGH AND VORT SWINGS THROUGH THE AREA IN ASSOCIATION
WITH THE SURFACE LOW OVER THE OHIO VALLEY. PRECIPITATION WILL MOVE
BACK IN QUICKLY THIS EVENING IN THE WARM AIR AHEAD OF A STRONG
COLD FRONT. PRECIPITATION WILL BE MORE SHOWERY...AND ALL RAIN AS
COLD AIR LAGS UNTIL AFTER THE PRECIPITATION ENDS.
STRONG FRONT SWEEPS THROUGH LATE TONIGHT INTO EARLY FRIDAY
MORNING. WITH STRONG COLD ADVECTION AND MIXING OF 40 TO 50 KT LOW
LEVEL WINDS ADVISORY LEVEL GUSTS WILL BE LIKELY DURING FRIDAY.
WITH A STRONG PRESSURE GRADIENT EVEN SOME OF THE SUSTAINED WINDS
WILL BE NEAR ADVISORY LEVELS. COLD ADVECTION SUBSIDES IN THE
AFTERNOON WITH SUBSIDING WINDS. HIGHS WILL LIKELY OCCUR EARLY IN
THE MORNING WITH TEMPERATURES FALLING THROUGH THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WINDS WILL SLOWLY DIMINISH LATE FRI NIGHT...BUT SHOULD PICK UP
AGAIN SAT MORNING THOUGH NOT REACHING SPEEDS QUITE AS HIGH AS
THOSE OF FRI. SLOW MOVING SFC COLD FRONT DROPPING DOWN FROM THE N
WILL MAINTAIN CLOUDS ESPECIALLY ACROSS INTERIOR SECTIONS. THIS
FRONT SHOULD MOVE THROUGH SAT NIGHT...FINALLY USHERING IN SOME
VERY COLD AIR FOR SAT NIGHT THROUGH MON AS STRONG CANADIAN HIGH
PRES BUILDS ACROSS.
AS THE HIGH MOVES TO THE EAST MON NIGHT INTO TUE...RETURN FLOW
BETWEEN THE HIGH AND AN APPROACHING COLD FRONT WILL BRING QUICK
MODERATION TO SEVERAL DEG ABOVE NORMAL TUE INTO TUE EVENING.
DEEP LAYER WAA AHEAD OF THE FRONT WILL SUPPORT A LARGE SWATH OF
PRE-FRONTAL CLOUDS TUE INTO TUE NIGHT...ALSO A FEW RAIN/SNOW SHOWERS
MAINLY TUE NIGHT. FAIR WX WITH NEAR AVG TEMPERATURES WILL RETURN FOR
WED.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE PASSES OVER THE METRO LATE THIS MORNING AND EARLY
AFTERNOON...THEN NE OF THE REGION THIS AFTERNOON. A POWERFUL COLD
FRONT PASSES FRI MRNG.
AS OF 1450Z...RAIN HAS MOVED NORTH AND EAST OF THE NYC TERMINALS
AND WILL CONTINUE MOVING TO THE NORTHEAST. MODERATE CONFIDENCE ON
CIGS/VSBYS WITH LOW STRATUS AND FOG CONTINUING OVER THE REGION.
MOST SIGNIFICANT CHANGE TO 15Z TAF UPDATE RELATES TO NYC TERMINAL
WINDS. LOOKS LIKE LOW PRESSURE WILL TRACK JUST EAST OF
NYC...CAUSING WINDS TO SHIFT N-NW LATE MORNING THROUGH EARLY
AFTERNOON BEFORE SETTLING TO THE SW. MODERATE CONFIDENCE REGARDING
GUSTS. GUSTS MAY DIMINISH EARLIER THAN FORECAST OVER THE NYC METROS.
LATEST DATA SUGGESTS MVFR CIGS LAST THRU THE DAY AND OVERNIGHT. BAND
OF RAIN LATE TONIGHT AHEAD OF THE COLD FRONT. THIS COULD MIX WITH
AND CHANGE TO SNOW...ESPECIALLY KSWF.
STRONG WINDS DEVELOP BEHIND THE COLD FRONT FRI MRNG.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE
MORNING INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN
W. GUSTS MAY DIMINISH EARLIER THAN FORECAST. PERIODIC MVFR VSBYS
PSBL.
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE
MORNING INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN
W. GUSTS MAY DIMINISH EARLIER THAN FORECAST. IFR CIGS PSBL AT TIMES.
KLGA FCSTER COMMENTS: CIGS/VSBYS MAY IMPROVE TO MVFR EARLIER THAN
FORECAST. AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE MORNING
INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN W. GUSTS
MAY DIMINISH EARLIER THAN FORECAST.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE
MORNING INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN
W. GUSTS MAY DIMINISH EARLIER THAN FORECAST. OCCASIONAL IFR CIGS PSBL.
KHPN FCSTER COMMENTS: CIGS/VSBYS MAY VARY BETWEEN IFR AND MVFR.
AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE MORNING INTO EARLY
AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN W. GUSTS MAY
DIMINISH EARLIER THAN FORECAST.
KISP FCSTER COMMENTS: CIGS/VSBYS MAY VARY BETWEEN IFR AND MVFR.
AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE MORNING INTO EARLY
AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN W. GUSTS MAY
DIMINISH EARLIER THAN FORECAST.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
FRI...CHANCE FOR IFR OR MVFR IN SNOW/RAIN SHOWERS. W-NW WINDS WITH
GUSTS ABOVE 40 KT.
SAT...VFR. FLURRIES POSSIBLE. GUSTY NW-W WINDS.
SUN...VFR. GUSTY N WINDS LATE.
MON...VFR.
&&
.MARINE...
GALES REMAIN UP ON ALL THE WATERS THIS MORNING. A STRONG LOW
LEVEL JET ASSOCIATED WITH AN AREA OF LOW PRESSURE PASSING OVER THE
AREA WATERS WILL MIX DOWN TO THE SURFACE BRINGING A PERIOD OF
STRONG GUSTY WINDS THIS MORNING. THE STRONGEST WINDS ARE EXPECTED
BETWEEN 5 AM AND 10 AM...WITH SOME LINGERING STRONGER GUSTS ACROSS
THE EASTERN WATERS. WINDS THEN RAPIDLY DIMINISH TO SMALL CRAFT
LEVELS THIS AFTERNOON. THERE MAY EVEN BE A PERIOD WHERE WINDS FALL
BELOW SMALL CRAFT LEVELS OVERNIGHT OUT AHEAD OF THE NEXT COLD
FRONT. SEAS HOWEVER WILL REMAIN AT SCA LEVELS.
SOUTHERLY WINDS RAPIDLY INCREASE ONCE AGAIN...THIS TIME OUT AHEAD
OF A COLD FRONT FRIDAY MORNING. HIGH CONFIDENCE EXISTS FOR STRONG
WESTERLY GALES DEVELOPING FRIDAY AND FRIDAY NIGHT BEHIND THE COLD
FRONT...WITH GUSTS UP TO 45 KT AND OCEAN SEAS BUILDING AS HIGH AS 16
FT OUT EAST FRI EVENING...AND UP TO 9 FT ON ERN LONG ISLAND SOUND.
THERE MAY EVEN BE A FEW GUSTS TO STORM FORCE. HAVE DECIDED NOT TO
ISSUE A NEW GALE WATCH OR WARNING FOR THIS EVENT TO AVOID CONFUSION
BETWEEN IT AND THE NEAR TERM FORECAST GALES...AS THERE SHOULD BE
ABOUT A 12-HR LULL BETWEEN THE TWO.
GALES SHOULD STILL BE ONGOING OVER THE OCEAN WATERS AND POSSIBLY THE
ERN SOUND/BAYS INTO SAT. GRADUAL IMPROVEMENT TO SUB-SCA EXPECTED SAT
NIGHT...WITH POSSIBLE OCEAN SCA CONDS RETURNING ON SUNDAY AS COLDER
AIR MOVES IN FROM THE NORTH.
&&
.HYDROLOGY...
RAINFALL AMOUNTS RANGED FROM 1 TO 1.5 INCHES FROM THIS EVENT. NO
FLOODING PROBLEMS ARE ANTICIPATED. AN ADDITIONAL TENTH TO TWO
TENTHS OF RAINFALL IS POSSIBLE LATE TONIGHT INTO FRIDAY MORNING.
DRY WEATHER RETURNS LATE FRIDAY THROUGH THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
THE COASTAL FLOOD ADVISORY HAS BEEN EXPANDED TO INCLUDE ALL ZONES
ADJACENT TO LI SOUND...AS WELL AS THE PECONIC AND GARDINERS BAYS.
THIS IS DUE TO A CHANGE IN LOW TRACK THAT HAS KEPT A STRONG...
PERSISTENT E/NE FLOW ACROSS LI SOUND. THIS HAS RESULTED IN
SIGNIFICANT TIDAL PILING WITH TIDAL DEPARTURES RUNNING AROUND 3
FT ABOVE NORMAL. THESE WATER LEVELS WILL BE SLOW TO RECEDE. IN FACT...
A COASTAL FLOOD WARNING MAY BE REQUIRED ACROSS WESTERN LI SOUND
SHOULD THESE LEVELS SHOW NO SIGH OF COMING DOWN IN THE NEXT HOUR.
THE COASTAL FLOOD ADVISORY ACROSS NY HARBOR AND THE SOUTH SHORE OF
WESTERN LI SOUND WILL EXPIRE AT NOON. THERE WAS WIDESPREAD MINOR
FLOODING ACROSS THESE AREAS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...COASTAL FLOOD ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
CTZ009>012.
NY...COASTAL FLOOD ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ071-073-078-079-081-176-177.
COASTAL FLOOD ADVISORY UNTIL NOON EST TODAY FOR NYZ072-074-075-
178-179.
NJ...COASTAL FLOOD ADVISORY UNTIL NOON EST TODAY FOR NJZ006-106-108.
MARINE...GALE WARNING UNTIL NOON EST TODAY FOR ANZ330-335-338-340-345-
350-353-355.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...KCS
MARINE...
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1104 AM EST THU JAN 12 2012
.SYNOPSIS...
A STORM SYSTEM FROM THE OHIO VALLEY TO THE SOUTHERN NEW ENGLAND
COAST WILL MOVE SLOWLY TO THE NORTH AND EAST THROUGH FRIDAY. A
STRONG COLD FRONT WILL MOVE ACROSS THE REGION EARLY FRIDAY
MORNING. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING LOW THROUGH
THE WEEKEND. HIGH PRESSURE REMAINS INTO THE BEGINNING OF THE WEEK.
ANOTHER COLD FRONT MOVES THROUGH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GREATEST PRESSURE FALLS WERE JUST OFF THE SE NEW ENGLAND COAST
LATE THIS MORNING. THIS WOULD SUPPORT THE COASTAL LOW TO THE
SOUTH OF LI TAKING A TRACK TO THE E/SE OF THE TRI-STATE AREA.
12Z NAM AND RUC SUPPORT SUCH A TRACK. THIS WILL IN PART PRODUCE
SOMEWHAT COOLER HIGHS TODAY...ESPECIALLY ACROSS THE INTERIOR...BUT
ALSO KEEP THE WINDS IN A MORE NORTHERLY DIRECTION. IN ADDITION...A
STRONG NE FLOW CONTINUES ACROSS COASTAL LOCATIONS THIS MORNING WITH
GUSTS UP TO 30 MPH. THE GRADIENT WILL SLACKEN BY THIS AFTERNOON AS
THE LOW TRACKS TO THE NE OF THE AREA. MORE IMPORTANTLY...THIS MAY
EXACERBATE COASTAL FLOODING ACROSS LI SOUND THIS AFTERNOON. REFER
TO COASTAL FLOOD SECTION BELOW.
AS FOR THE RAIN AND EMBEDDED THUNDERSTORMS...THE MAIN AREA ACROSS
EASTERN CT AND EASTERN LI WILL LIFT TO THE NE AND CLEAR THE AREA
BY NOONTIME. THERE MAY BE PATCHES OF LIGHT RAIN THROUGH THE
AFTERNOON WITH WEAK LIFT AND MOISTURE IN PLACE.
DUE TO THE LOW TRACK...HIGHS WERE ADJUSTED DOWNWARD SEVERAL
DEGREES...MAINLY ACROSS THE INTERIOR. HIGHS MAY NOT GET OUT OF
THE UPPER 30S WELL INLAND. ELSEWHERE...TEMPS SHOULD HOLD STEADY
OR SLIGHTLY FALL FROM THEIR CURRENT READINGS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
NEXT UPPER TROUGH AND VORT SWINGS THROUGH THE AREA IN ASSOCIATION
WITH THE SURFACE LOW OVER THE OHIO VALLEY. PRECIPITATION WILL MOVE
BACK IN QUICKLY THIS EVENING IN THE WARM AIR AHEAD OF A STRONG
COLD FRONT. PRECIPITATION WILL BE MORE SHOWERY...AND ALL RAIN AS
COLD AIR LAGS UNTIL AFTER THE PRECIPITATION ENDS.
STRONG FRONT SWEEPS THROUGH LATE TONIGHT INTO EARLY FRIDAY
MORNING. WITH STRONG COLD ADVECTION AND MIXING OF 40 TO 50 KT LOW
LEVEL WINDS ADVISORY LEVEL GUSTS WILL BE LIKELY DURING FRIDAY.
WITH A STRONG PRESSURE GRADIENT EVEN SOME OF THE SUSTAINED WINDS
WILL BE NEAR ADVISORY LEVELS. COLD ADVECTION SUBSIDES IN THE
AFTERNOON WITH SUBSIDING WINDS. HIGHS WILL LIKELY OCCUR EARLY IN
THE MORNING WITH TEMPERATURES FALLING THROUGH THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WINDS WILL SLOWLY DIMINISH LATE FRI NIGHT...BUT SHOULD PICK UP
AGAIN SAT MORNING THOUGH NOT REACHING SPEEDS QUITE AS HIGH AS
THOSE OF FRI. SLOW MOVING SFC COLD FRONT DROPPING DOWN FROM THE N
WILL MAINTAIN CLOUDS ESPECIALLY ACROSS INTERIOR SECTIONS. THIS
FRONT SHOULD MOVE THROUGH SAT NIGHT...FINALLY USHERING IN SOME
VERY COLD AIR FOR SAT NIGHT THROUGH MON AS STRONG CANADIAN HIGH
PRES BUILDS ACROSS.
AS THE HIGH MOVES TO THE EAST MON NIGHT INTO TUE...RETURN FLOW
BETWEEN THE HIGH AND AN APPROACHING COLD FRONT WILL BRING QUICK
MODERATION TO SEVERAL DEG ABOVE NORMAL TUE INTO TUE EVENING.
DEEP LAYER WAA AHEAD OF THE FRONT WILL SUPPORT A LARGE SWATH OF
PRE-FRONTAL CLOUDS TUE INTO TUE NIGHT...ALSO A FEW RAIN/SNOW SHOWERS
MAINLY TUE NIGHT. FAIR WX WITH NEAR AVG TEMPERATURES WILL RETURN FOR
WED.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE PASSES OVER THE METRO LATE THIS MORNING AND EARLY
AFTERNOON...THEN NE OF THE REGION THIS AFTERNOON. A POWERFUL COLD
FRONT PASSES FRI MRNG.
AS OF 1450Z...RAIN HAS MOVED NORTH AND EAST OF THE NYC TERMINALS
AND WILL CONTINUE MOVING TO THE NORTHEAST. MODERATE CONFIDENCE ON
CIGS/VSBYS WITH LOW STRATUS AND FOG CONTINUING OVER THE REGION.
MOST SIGNIFICANT CHANGE TO 15Z TAF UPDATE RELATES TO NYC TERMINAL
WINDS. LOOKS LIKE LOW PRESSURE WILL TRACK JUST EAST OF
NYC...CAUSING WINDS TO SHIFT N-NW LATE MORNING THROUGH EARLY
AFTERNOON BEFORE SETTLING TO THE SW. MODERATE CONFIDENCE REGARDING
GUSTS. GUSTS MAY DIMINISH EARLIER THAN FORECAST OVER THE NYC METROS.
LATEST DATA SUGGESTS MVFR CIGS LAST THRU THE DAY AND OVERNIGHT. BAND
OF RAIN LATE TONIGHT AHEAD OF THE COLD FRONT. THIS COULD MIX WITH
AND CHANGE TO SNOW...ESPECIALLY KSWF.
STRONG WINDS DEVELOP BEHIND THE COLD FRONT FRI MRNG.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE
MORNING INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN
W. GUSTS MAY DIMINISH EARLIER THAN FORECAST. PERIODIC MVFR VSBYS
PSBL.
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE
MORNING INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN
W. GUSTS MAY DIMINISH EARLIER THAN FORECAST. IFR CIGS PSBL AT TIMES.
KLGA FCSTER COMMENTS: CIGS/VSBYS MAY IMPROVE TO MVFR EARLIER THAN
FORECAST. AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE MORNING
INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN W. GUSTS
MAY DIMINISH EARLIER THAN FORECAST.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE
MORNING INTO EARLY AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN
W. GUSTS MAY DIMINISH EARLIER THAN FORECAST. OCCASIONAL IFR CIGS PSBL.
KHPN FCSTER COMMENTS: CIGS/VSBYS MAY VARY BETWEEN IFR AND MVFR.
AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE MORNING INTO EARLY
AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN W. GUSTS MAY
DIMINISH EARLIER THAN FORECAST.
KISP FCSTER COMMENTS: CIGS/VSBYS MAY VARY BETWEEN IFR AND MVFR.
AMENDMENTS LIKELY TO REFINE WIND SHIFTS LATE MORNING INTO EARLY
AFTERNOON...BUT SHOULD TREND TO N-NW AND THEN W. GUSTS MAY
DIMINISH EARLIER THAN FORECAST.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
FRI...CHANCE FOR IFR OR MVFR IN SNOW/RAIN SHOWERS. W-NW WINDS WITH
GUSTS ABOVE 40 KT.
SAT...VFR. FLURRIES POSSIBLE. GUSTY NW-W WINDS.
SUN...VFR. GUSTY N WINDS LATE.
MON...VFR.
&&
.MARINE...
GUSTS UP TO 45 KT POSSIBLE ACROSS EASTERN LI SOUND THROUGH MID
MORNING AS THE LOW-LEVEL JET PIVOTS ACROSS THE WATERS.
GALES REMAIN UP ON ALL THE WATERS THIS MORNING. A STRONG LOW LEVEL
JET ASSOCIATED WITH AN AREA OF LOW PRESSURE PASSING OVER THE AREA
WATERS WILL MIX DOWN TO THE SURFACE BRINGING A PERIOD OF STRONG
GUSTY WINDS THIS MORNING. THE STRONGEST WINDS ARE EXPECTED BETWEEN 5
AM AND 10 AM...WITH SOME LINGERING STRONGER GUSTS ACROSS THE EASTERN
WATERS. WINDS THEN RAPIDLY DIMINISH TO SMALL CRAFT LEVELS THIS
AFTERNOON. THERE MAY EVEN BE A PERIOD WHERE WINDS FALL BELOW SMALL
CRAFT LEVELS OVERNIGHT OUT AHEAD OF THE NEXT COLD FRONT. SEAS
HOWEVER WILL REMAIN AT SCA LEVELS.
SOUTHERLY WINDS RAPIDLY INCREASE ONCE AGAIN...THIS TIME OUT AHEAD
OF A COLD FRONT FRIDAY MORNING. HIGH CONFIDENCE EXISTS FOR STRONG
WESTERLY GALES DEVELOPING FRIDAY AND FRIDAY NIGHT BEHIND THE COLD
FRONT...WITH GUSTS UP TO 45 KT AND OCEAN SEAS BUILDING AS HIGH AS 16
FT OUT EAST FRI EVENING...AND UP TO 9 FT ON ERN LONG ISLAND SOUND.
THERE MAY EVEN BE A FEW GUSTS TO STORM FORCE. HAVE DECIDED NOT TO
ISSUE A NEW GALE WATCH OR WARNING FOR THIS EVENT TO AVOID CONFUSION
BETWEEN IT AND THE NEAR TERM FORECAST GALES...AS THERE SHOULD BE
ABOUT A 12-HR LULL BETWEEN THE TWO.
GALES SHOULD STILL BE ONGOING OVER THE OCEAN WATERS AND POSSIBLY THE
ERN SOUND/BAYS INTO SAT. GRADUAL IMPROVEMENT TO SUB-SCA EXPECTED SAT
NIGHT...WITH POSSIBLE OCEAN SCA CONDS RETURNING ON SUNDAY AS COLDER
AIR MOVES IN FROM THE NORTH.
&&
.HYDROLOGY...
THREE QUARTERS TO AROUND 1 INCH OF RAINFALL IS EXPECTED THROUGH
MIDDAY TODAY. MINOR URBAN AND POOR DRAINAGE FLOODING IS POSSIBLE
THIS MORNING.
AN ADDITIONAL TENTH TO TWO TENTHS OF RAINFALL IS POSSIBLE LATE
TONIGHT INTO FRIDAY MORNING. DRY WEATHER RETURNS LATE FRIDAY
THROUGH THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
THE COASTAL FLOOD ADVISORY HAS BEEN EXPANDED TO INCLUDE ALL ZONES
ADJACENT TO LI SOUND...AS WELL AS THE PECONIC AND GARDINERS BAYS.
THIS IS DUE TO A CHANGE IN LOW TRACK THAT HAS KEPT A STRONG...
PERSISTENT E/NE FLOW ACROSS LI SOUND. THIS HAS RESULTED IN
SIGNIFICANT TIDAL PILING WITH TIDAL DEPARTURES RUNNING AROUND 3
FT ABOVE NORMAL. THESE WATER LEVELS WILL BE SLOW TO RECEDE. IN FACT...
A COASTAL FLOOD WARNING MAY BE REQUIRED ACROSS WESTERN LI SOUND
SHOULD THESE LEVELS SHOW NO SIGH OF COMING DOWN IN THE NEXT HOUR.
THE COASTAL FLOOD ADVISORY ACROSS NY HARBOR AND THE SOUTH SHORE OF
WESTERN LI SOUND WILL EXPIRE AT NOON. THERE WAS WIDESPREAD MINOR
FLOODING ACROSS THESE AREAS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
CTZ009.
NY...COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ072-
074-075-178-179.
COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ071-073-176-177.
NJ...COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NJZ006-
106-108.
MARINE...GALE WARNING UNTIL NOON EST TODAY FOR ANZ330-335-338-340-345-
350-353-355.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
335 PM CST THU JAN 12 2012
.DISCUSSION...
134 PM CST
LIGHT TO MODERATE SNOWFALL CONTINUES ACROSS THE AREA EARLY THIS
AFTERNOON. RADAR TRENDS AND SHORT TERM GUIDANCE SHOW TWO AREAS OF
BETTER FORCING WITHIN THE BROAD LIFT. THE FIRST IS ORIENTED FROM
BENTON HARBOR MICHIGAN NORTHWEST ACROSS MILWAUKEE WITH A SECOND
STARTING TO TAKE SHAPE FROM RENSSELAER TO PRINCETON TO SAVANNA. IN
BETWEEN...RADAR RETURNS HAVE EASED OFF SOMEWHAT BUT SNOWFALL
CONTINUES. OVERALL NEAR TERM TRENDS SUGGEST THAT
FORCING/FRONTOGENESIS WILL BECOME MORE FOCUSED OVER THE CWA INTO
LATE AFTERNOON...WITH PERHAPS THE MOST FOCUSED FORCING OVER NE
IL/NW IN EARLY THIS EVENING.
IN ADDITION...LOW LEVEL AREA OF CONVERGENCE OVER THE LAKE
CONTINUES TO COMPLICATE NEAR TERM DETAILS. LATEST RUC SHOWS AN
EAST-WEST BAND OF CONVERGENCE FROM THE LAKE/COOK IL BORDER
EASTWARD. THIS TROUGH IS NOT SO EVIDENT IN SHORE OBS BUT ORD TDWR
SHOWS A SOUTHWESTWARD MOVING AREA OF ENHANCED REFLECTIVITY MOVING
INLAND FROM EVANSTON SOUTHWARD INTO DOWNTOWN CHICAGO. LAKE
INFLUENCE WILL LIKELY BE RATHER TRANSIENT BUT IS SEEMINGLY ABLE TO
OCCUR...AND MAY BECOME MORE FAVORED AS LOW-LEVEL THERMAL PROFILES
COOL. THE EXTENT TO WHICH IT OCCURS IS STILL NOT CLEAR BUT AREAS
ALONG THE COOK COUNTY IL SHORE SEEM MOST FAVORED INTO MID
AFTERNOON BEFORE IT PIVOTS INTO NORTHWEST INDIANA LATE THIS
AFTERNOON/EARLY THIS EVENING.
MDB
//PREV DISCUSSION...
1110 AM CST
HAVE OPTED TO UPGRADE THE WINTER WEATHER ADVISORY TO A WINTER
STORM WARNING FOR MUCH OF NORTHEAST IL AND NORTHWEST IN. RADAR
TRENDS SHOW THE MAIN BAND OF SNOW INTENSIFYING AND BECOMING MORE
WIDESPREAD ACROSS MUCH OF THE FORECAST AREA AS IT LIFT
NORTHEASTWARD AND BEGINS TO PIVOT COUNTER-CLOCKWISE.
FRONTOGENETICAL FORCING BECOME BETTER FOCUSED AS MID LEVEL TROUGH
SWINGS ACROSS THE AREA BRINGING IN WARM ADVECTION FROM THE EAST
AND COLD ADVECTION FROM THE WEST. IN ADDITION...FOCUSING MAY BE
FURTHER ENHANCED BY THE PRESENCE OF A MID LEVEL TROUGH OF WARM AIR
ALOFT. THIS SYNOPTIC FORCING BY ITSELF SUGGESTS THAT SNOWFALL
RATES WILL BE HIGHER FROM MID AFTERNOON THROUGH EARLY EVENING
RESULTING IN 4-8 INCH TOTALS IN A SHORTER AMOUNT OF TIME. IN
ADDITION LAKE ENHANCEMENT IN SOME FORM STILL LOOKS POSSIBLE LATE
THIS AFTERNOON...BUT WILL BE VERY CHALLENGING TO PIN DOWN. SURFACE
OBS AROUND THE SOUTHERN SHORE STILL SHOW SIGNS OF A CIRCULATION
WITH RADAR SHOWING A NORTHWEST-SOUTHEAST ORIENTED BAND OF PRECIP
WHICH MAY BE REFLECTIVE MORE OF A ELONGATED CONVERGENCE AREA.
SEVERAL RECENT RUNS OF THE RUC/HRRR SHOW A CLOSED CIRCULATION
SHIFTING WESTWARD TOWARD THE IL SHORE THIS AFTERNOON WITH OTHER
GUIDANCE SHOWING AT LEAST SOME SORT OF SHORELINE CONVERGENCE
DEVELOPING. THE CHALLENGE WILL BE FOR THIS TO CONTINUE IN THE
MIDST OF INCREASING NORTHWESTERLY LOW LEVEL FLOW...WHICH HAS BEEN
SLOWER TO ADVANCE EASTWARD. SHOULD THIS LAKE ENHANCEMENT/BANDING
OCCUR...AND THIS IS STILL UNCERTAIN...THEN SOME AREAS COULD EASILY
SEE 8-10 INCHES OR POSSIBLY MORE BUT THIS WOULD LIKELY BE VERY
LOCALIZED. EVEN WITHOUT LAKE ENHANCEMENT SNOWFALL RATES ARE
EXPECTED TO BE HEAVIEST DURING THE AFTERNOON/EVENING RUSH
HOUR...WITH IMPACTS MAGNIFIED UNDER ANY LAKE BANDS. GUSTY WINDS
WILL SPREAD IN FROM THE WEST THROUGH THE AFTERNOON ACROSS NORTH
CENTRAL ILLINOIS AND INTO THE CHICAGO METRO LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN INTO NW INDIANA.
MDB
//PREV DISCUSSION...
309 AM CST
NEAR TERM (NOW THROUGH FRIDAY)...
VERY LITTLE CHANGE FROM PREVIOUS FORECAST WITH ONLY REAL ADJUSTMENT
BEING UPGRADING TO A WARNING FOR PORTER COUNTY DUE TO SOME LAKE
ENHANCEMENT THIS AFTERNOON POSSIBLY INTO VERY EARLY THIS EVENING.
POTENT VORT MAX EVIDENT ON WATER VAPOR IMAGERY OVER KS EARLY THIS
MORNING WILL CONTINUE TO CHARGE EASTWARD AND RESULT IN ENTIRE TROUGH
AXIS BECOMING INCREASINGLY NEGATIVELY TILTED TODAY INTO TONIGHT. AS
THIS OCCURS THE NORTH-SOUTH AXIS OF LIGHT-MODERATE SNOW EXTENDING
FROM WESTERN WI SOUTH INTO MISSOURI AT 09Z IS LIKELY TO GRADUALLY
BECOME RE-ORIENTED INTO A MORE NW-SE AXIS AS IT SHIFTS SLOWLY
EASTWARD. THE RE-ORIENTATION THATS EXPECTED TO TAKE PLACE WILL
RESULT IN A DECELERATION OF THE EASTWARD PROGRESSION OF THE SNOW
OVER NORTHWEST ILLINOIS AND STILL ANTICIPATE IT BEING LATE MORNING
BEFORE SNOW BREAKS OUT IN METRO CHICAGO AND POSSIBLY NOT TIL MID
MORNING AS FAR WEST AS ROCKFORD.
AS HAS BEEN NOTED FOR A COUPLE DAYS NOW...THE SYSTEM WILL NOT HAVE
AN ABUNDANCE OF MOISTURE TO WORK WITH HOWEVER WHAT IT LACKS IN
MOISTURE IT LOOKS TO MAKE UP FOR IN FORCING AND DURATION. AS THE
INTENSE COMPACT CLOSED LOW PLOWS EAST ITS PROGGED TO DEEPEN TODAY
RESULTING IN VERY IMPRESSIVE 12HR/500MB HEIGHT FALLS OVER 200DM VERY
DEEP MODERATE ASCENT EXPECTED. SYNOPTICALLY STILL APPEARS AS THOUGH
QPF ACROSS THE CWA WILL BE FAIRLY UNIFORM AND SUPPORTIVE OF A SOLID
4-8 INCH SNOWFALL CWA-WIDE. THERMAL PROFILES ARE A BIT WARMER THAN
IN PREVIOUS RUNS RESULTING IN SLIGHTLY LESS FAVORABLY DEEP DENDRITIC
GROWTH ZONE (DGZ) WHICH COULD CUT BACK ON SNOW:LIQUID RATIOS A BIT.
IN ADDITION...THE STRONG WINDS ALSO ARE NOT SUPPORTIVE OF
EXCEPTIONALLY HIGH SNOW:LIQUID RATIOS AND THINK A REASONABLE BALL
PARK GUESS IS THAT THEY WILL GENERALLY END UP IN THE BALLPARK OF
10-15:1.
INTERESTINGLY...SOME OF THE HI-RES MESOSCALE MODELS ARE SUGGESTING
THAT THERE COULD BE SOME MESOSCALE BANDING OF HEAVY SNOW DEVELOPING
BY THIS AFTERNOON OVER PORTIONS OF OUR CWA IN ASSOCIATION WITH
STRENGTHENING LOW LEVEL FRONTOGENETIC CIRCULATION. SHOULD THAT OCCUR
IT WOULD NOT BE AT ALL HARD TO ENVISION A BAND OF SNOWFALL TOTALS IN
8-12 INCH RANGE...PARTICULARLY CLOSE TO PIVOT POINT WHERE HEAVIER
SNOW BAND WILL SIT THE LONGEST AS THE ORIENTATION GOES FROM WNW-ESE
TO MORE NE-SW TONIGHT. REALLY IMPOSSIBLE TO PINPOINT THOSE TYPE OF
MESO-BETA SCALE TYPE PHENOMENA THIS FAR IN ADVANCE SO RATHER THAN
BLANKETING 23 COUNTIES WITH A WARNING WHEN ITD PROBABLY ONLY BE A
FRACTION OF THOSE REACH CRITERIA HAVE OPTED TO LET THE ADVISORY
RIDE WITH 4-8 INCH AMOUNTS AND JUST MENTION LOCALLY HEAVIER TOTALS
IN THE WSW. AS MESOSCALE DETAILS START TO UNFOLD LATER TODAY ITS
POSSIBLE THAT THE DAY SHIFT MAY NEED TO UPGRADE PORTIONS OF THE
ADVISORY TO A WARNING.
HAVE OPTED TO UPGRADE PORTER COUNTY INDIANA TO A WARNING...AS LOW
LEVEL TRAJECTORIES COULD ALLOW FOR A PERIOD OF LAKE ENHANCED
SNOWFALL THIS AFTERNOON. THE WINDOW OF OPPORTUNITY FOR LAKE
ENHANCEMENT FOR NE PORTER LOOKS SMALL AS CONDITIONS ARE LIKELY TO
BECOMING INCREASINGLY SUPPORTIVE OF LAKE ENHANCEMENT THIS AFTERNOON
BUT AT THE SAME TIME WINDS WILL BE BACKING WHICH SHOULD SENDING ANY
THREAT OF LAKE ENHANCEMENT EAST INTO IWX-LAND. BEFORE THAT OCCURS
SEEMS PLAUSIBLE THAT THE OCCURS COULD EASILY SEE NE PORTER PICKING
UP A COUPLE BONUS INCHES OF SNOW OFF THE LAKE.
SNOW LOOKS TO START WINDING DOWN AFTER MIDNIGHT AND ENDING
EVERYWHERE BY MID-LATE MORNING FRIDAY. NO CHANGES PLANNED TO THE
TIMING OF THE HEADLINES. WITH WINDS LIKELY TO GUST TO OVER 30 MPH
THIS AFTERNOON AND TONIGHT BLOWING AND DRIFTING SNOW WILL LIKELY BE
AN ISSUE WITH THIS STORM...PARTICULARLY TONIGHT AS SNOW BECOMES
FLUFFIER INCREASING ITS "BLOW-ABILITY".
IZZI
IN-BETWEEN TERM (FRIDAY NIGHT THROUGH SATURDAY NIGHT)...
IN THE WAKE OF THE STORM FOCUS WILL TURN TO TEMPS FRIDAY
NIGHT...WHICH WILL ULTIMATELY BE CLOSELY TIED TO HOW MUCH (IF ANY
CLEARING) WE SEE. MODELS ALL SUGGEST THAT STRATUS WILL CLEAR OUT
FRIDAY EVENING...BUT MODELS ARE ALSO NOTORIOUS FOR BREAKING STRATUS
UP TOO QUICKLY. SUSPECT THAT THERE IS A VERY REAL CHANCE THAT THE
STRATUS MAY NOT CLEAR OUT AT ALL BEFORE CLOUDINESS WITH SATURDAY`S
CLIPPER ARRIVES LATE FRIDAY NIGHT INTO SAT MORNING. GIVEN THE LOW
CONFIDENCE AT THIS DISTANCE HAVE TAKEN A CONSERVATIVE/MIDDLE OF THE
ROAD APPROACH TO TEMPS. ON THE ONE EXTREME...IF SKIES CLEAR OUT
WITH THE SURFACE RIDGE AXIS APPROACHING ITS A VERY REAL
POSSIBILITY THAT LOWS COULD DROP TO BETWEEN ZERO TO
-10...PARTICULARLY OVER NORTH CENTRAL ILLINOIS. CONVERSELY...IF
STRATUS HANGS ON TEMPS MAY END UP MOST IN THE LOW TO MID
TEENS...WHICH I SUSPECT IS PROBABLY THE MORE LIKELY SCENARIO.
BY SATURDAY A FAST MOVING CLIPPER IS PROGGED TO ZIP SOUTHEASTWARD
ACROSS THE MIDWEST. NOT AN OVERLY STRONG SYSTEM AND WILL BE MOISTURE
STARVED...BUT WITH PERSISTENT WARM AIR ADVECTION MIGHT BE ABLE TO
LAY DOWN A BAND OF AN INCH OR SO OF SNOW. MODELS GENERALLY TRACK
SURFACE LOW FROM NORTHERN IOWA INTO SOUTHERN ILLINOIS WHICH WOULD
FAVOR OUR WESTERN CWA FOR HIGHEST CHANCES OF SNOW. HAVE TRENDED POPS
UP IN THE GRIDS AGAIN...WELL ABOVE MOS GUIDANCE AND MORE IN LINE
WITH HPC QPF FORECAST OF GREATER THAN A TENTH OF AN INCH. CLIPPER
SHOULD BE OUT OF THE AREA BY LATER SATURDAY EVENING WITH CLOUDS
PROBABLY STICKING AROUND AND KEEPING TEMPS SOMEWHAT IN CHECK
SATURDAY NIGHT.
IZZI
LONG TERM (SUNDAY THROUGH WEDNESDAY)...
THE POLAR JET WHICH HAD BEEN ANCHORED TO OUR NORTH MUCH OF THE
WINTER WILL BE MORE PRESENT OVER THE MID-SECTION OF THE COUNTRY.
THIS SEEMS TIED TO A MORE ORGANIZED POLAR VORTEX DEVELOPING OVER
NORTHERN CANADA/BAFFIN ISLAND...A FEATURE CONDUCIVE FOR STEERING
COLD AIR PERIODS INTO CENTRAL CANADA AND OFTEN THE EASTERN HALF OF
THE U.S. THAT SAID...A RECOVERY FROM OUR IMMEDIATE COLD AIR SNAP
WILL BE SEEN AT THE START OF NEXT WEEK WITH 850 MB TEMPERATURES
RETURNING TO ABOVE ZERO BY MONDAY WITHIN DEEP SOUTHWEST FLOW. THE
PATTERN ACTUALLY WILL BRIEFLY RESEMBLE MUCH OF THE PAST
MONTH...HOWEVER ANTICIPATED SNOW COVER ON THE GROUND THROUGHOUT THE
REGION SHOULD KEEP THE NEAR-SURFACE AIR MASS COOLER THAN WHAT WE
HAVE SEEN RECENTLY WITH THE SAME TYPE OF AIR MASS. IN
ADDITION...MORE COLUMN MOISTURE IS PROJECTED IN ALL LONG RANGE
GUIDANCE DURING MONDAY...A HINT AT STRATUS WHICH WOULD BE MORE
FAVORED WITH MOIST AND MILD RETURN FLOW OVER SNOW COVER. HAVE GUIDED
MORE TOWARDS A BLEND OF RAW GUIDANCE FOR HIGHS AS OPPOSED TO THE
BIAS-CORRECTED WHICH HAS WORKED SO WELL FOR HIGH TEMPERATURES THE
PAST MONTH TO MONTH AND A HALF. FOR SUN NIGHT AND MON NIGHT HAVE
TRENDED TOWARDS THE MILDER BIAS-CORRECTED FORECASTS.
A COLD FRONT IS EXPECTED TO WORK THROUGH SOMETIME MONDAY NIGHT OR
TUESDAY...WITH A POTENTIAL LOW DEVELOPING ALONG IT DURING THAT
PERIOD. A MEAN SOLUTION ON THE MODELS HAS A LOW TRACKING NEAR OR
JUST TO THE WEST OF THE AREA. THIS WOULD AT LEAST INTRODUCE
THICKNESSES SUPPORTIVE OF RAIN/DRIZZLE DURING MONDAY AND MONDAY
NIGHT IN ANY PRECIPITATION THAT FALLS...AND THE CHANCE FOR
POTENTIALLY RAIN CHANGING TO SNOW LATER ON. SLOWER HAS BEEN BETTER
WITH SYSTEMS RECENTLY...AND THE 12.00 EC SLOWED EVEN FURTHER FROM
ITS PRECEDING RUN. CONFIDENCE IN THIS PERIOD IS LOW THOUGH WITH A
LOW DEVELOPING ALONG A FRONT WITH A SYSTEM THAT IS STILL WELL
OFFSHORE THE WEST COAST. INTERESTINGLY ENOUGH...DEW POINTS ARE
FORECAST TO CREEP UP TO THE MID 30S TO POSSIBLY LOWER 40S IN THE
FORECAST AREA...WHICH COMBINED WITH ANY RAIN/DRIZZLE WOULD LEAD TO
QUICK SNOW MELT AND POSSIBLY ADVECTION FOG.
BEYOND...BOTH THE 12.00 GFS AND EC HAVE THE NEXT COLD AIR DOME BUILT
IN SOUTHERN CANADA BY MIDWEEK WITH 850 MB TEMPS OF -30C OR COLDER.
THEY BOTH DIFFER VASTLY FROM RUN TO RUN IN HOW FAR SOUTH AND EAST
AND HOW QUICKLY THIS EVOLVES...AND WHETHER OR NOT IT WILL EVEN GET
HERE. THE JET LOOKS TO REMAIN ACTIVE AS WELL...SO CONFIDENCE IN THIS
PERIOD IS LOW.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WEST/NORTHWEST WINDS SLOWLY INCREASING THROUGH THE REMAINDER OF
THE AFTERNOON WITH THE STRONGER GUSTS EXPECTED LATE THIS
AFTERNOON/EARLY EVENING.
* PREVAILING IFR CEILINGS STILL EXPECTED THROUGH THE REMAINDER OF
THE DAY/NIGHT.
* LIGHT TO MODERATE SNOW TO CONTINUE THIS AFTERNOON WITH PERIODS
OF HEAVIER SNOW STILL POSSIBLE. VIS OF 1/2SM EXPECTED WITH
PERIODS OF 1/4SM.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
LARGE AREA OF LIGHT TO MODERATE SNOW CONTINUES TO DEVELOP AND
SLOWLY MOVE ACROSS THE TERMINALS EARLY THIS AFTERNOON AS LARGE
SCALE FORCING MOVES THROUGH THE REGION. EXPECT THIS LIGHT TO
MODERATE SNOW TO PERSIST INTO THE AFTERNOON AND EVEN EXPECT AN
INCREASE IN INTENSITY WITH PERIODS OF HEAVY SNOW POSSIBLE. VIS
LOOKS TO HOLD AROUND 1/2SM WITH PERIODS OF 1/4SM POSSIBLE LATER
THIS AFTERNOON. THIS PERIOD OF HEAVIER SNOW IS EXPECTED TO
CONTINUE INTO THE EARLY AFTERNOON AND EARLY EVENING WITH SNOWFALL
RATES ALSO BECOMING AN ISSUE. LATER THIS EVENING...LIGHT TO
MODERATE SNOW CAN STILL BE EXPECTED WITH SOME UNCERTAINTY AS TO IF
ANOTHER PERIOD OF HEAVIER SNOW COULD BE OBSERVED. WILL CONTINUE TO
MONITOR LATEST TRENDS AND ADJUST ACCORDINGLY FOR THE EARLY EVENING
TIME FRAME. THEN EXPECT THE HEAVIEST SNOW TO START SHIFTING EAST
LATE IN THE EVENING. CEILINGS ARE LOCKED IN AT IFR AND WILL REMAIN
FOR THE REMAINDER OF TODAY AND TONIGHT...BEFORE A SLOW UPWARD
TRENDS TO MVFR BY MID TO LATE MORNING ON FRIDAY AS THIS SYSTEM
SLOWLY TRANSITIONS TO THE EAST.
WEST/NORTHWEST WINDS HAVE BEEN SLOW TO INCREASE TODAY BUT STILL
EXPECT THEM TO INCREASE LATER THIS AFTERNOON AND EVENING.
WINDS/GUSTS WILL INCREASE TO AROUND THE 25KT RANGE DURING THAT
TIME WITH A MORE NORTHWEST WIND EXPECTED AS SURFACE TROUGH PUSHES
THROUGH. WEST/NORTHWEST WINDS WILL THEN SLOWLY DIMINISH FRIDAY
MORNING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH CEILINGS AND TRENDS TODAY/TONIGHT.
* MEDIUM HIGH CONFIDENCE WITH SNOW/VIS TRENDS TODAY...WITH MEDIUM
CONFIDENCE OF SNOW/VIS TRENDS TONIGHT INTO EARLY FRIDAY MORNING.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...CHANCE OF SNOW WITH MVFR OR IFR CIGS/VIS DEVELOPING BY
THE AFTERNOON AND CONTINUING INTO THE NIGHT.
SUNDAY...VFR. WX NIL.
MONDAY...IFR CIGS/VIS IN DRIZZLE OR LIGHT RAIN.
TUESDAY...CHANCE OF SNOW WITH MVFR CIGS/VIS.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
335 PM CST
LOW PRESSURE OF OVER THE FAR SOUTH END OF LAKE HURON AT MID
AFTERNOON DEEPENS AS IT MOVES EAST OVER THE LOWER GREAT LAKES
TONIGHT...AND THEN NORTHEAST UP THE ST. LAWRENCE VALLEY ON
FRIDAY. MEANWHILE...HIGH PRESSURE WILL GRADUALLY MOVE FROM
MANITOBA TO WESTERN ONTARIO. THE STRONG PRESSURE GRADIENT BETWEEN
THE LOW AND THE HIGH...ALONG WITH A SURGE OF COLD AIR...WILL
RESULT IN GALE FORCE WINDS TONIGHT AND INTO FRIDAY AFTERNOON.
WINDS WILL BEGIN TO RELAX LATER FRIDAY AS THE LOW MOVES FARTHER
AWAY AND HIGH PRESSURE MOVES SOUTHEAST ACROSS ONTARIO. LOW
PRESSURE OF MOVES SOUTHEAST ACROSS THE CANADIAN PRAIRIE
PROVIDENCES FRIDAY NIGHT BUT THEN WEAKENS AS IT CONTINUES ON TO
THE UPPER GREAT LAKES SATURDAY. ANOTHER LOW WILL MOVE EAST ACROSS
SOUTH CENTRAL CANADA SATURDAY NIGHT THROUGH SUNDAY NIGHT...THEN
TURN NORTHEASTWARD AND REACH JAMES BAY MONDAY NIGHT. DEPENDING ON
THE STRENGTH OF THIS LOW IT COULD POTENTIALLY PRODUCE GALES
TUESDAY AND TUESDAY NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-ILZ020-
ILZ022 UNTIL 9 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-
ILZ019-ILZ021-ILZ032 UNTIL 4 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ023-ILZ033-ILZ039 UNTIL 9 AM FRIDAY.
IN...WINTER STORM WARNING...INZ001-INZ002 UNTIL 9 AM FRIDAY.
WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019 UNTIL 9 AM FRIDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL
MIDNIGHT SATURDAY.
GALE WARNING...LMZ744-LMZ745...9 PM THURSDAY TO 3 PM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 9 PM
THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
224 PM CST THU JAN 12 2012
.DISCUSSION...
134 PM CST
LIGHT TO MODERATE SNOWFALL CONTINUES ACROSS THE AREA EARLY THIS
AFTERNOON. RADAR TRENDS AND SHORT TERM GUIDANCE SHOW TWO AREAS OF
BETTER FORCING WITHIN THE BROAD LIFT. THE FIRST IS ORIENTED FROM
BENTON HARBOR MICHIGAN NORTHWEST ACROSS MILWAUKEE WITH A SECOND
STARTING TO TAKE SHAPE FROM RENSSELAER TO PRINCETON TO SAVANNA. IN
BETWEEN...RADAR RETURNS HAVE EASED OFF SOMEWHAT BUT SNOWFALL
CONTINUES. OVERALL NEAR TERM TRENDS SUGGEST THAT
FORCING/FRONTOGENESIS WILL BECOME MORE FOCUSED OVER THE CWA INTO
LATE AFTERNOON...WITH PERHAPS THE MOST FOCUSED FORCING OVER NE
IL/NW IN EARLY THIS EVENING.
IN ADDITION...LOW LEVEL AREA OF CONVERGENCE OVER THE LAKE
CONTINUES TO COMPLICATE NEAR TERM DETAILS. LATEST RUC SHOWS AN
EAST-WEST BAND OF CONVERGENCE FROM THE LAKE/COOK IL BORDER
EASTWARD. THIS TROUGH IS NOT SO EVIDENT IN SHORE OBS BUT ORD TDWR
SHOWS A SOUTHWESTWARD MOVING AREA OF ENHANCED REFLECTIVITY MOVING
INLAND FROM EVANSTON SOUTHWARD INTO DOWNTOWN CHICAGO. LAKE
INFLUENCE WILL LIKELY BE RATHER TRANSIENT BUT IS SEEMINGLY ABLE TO
OCCUR...AND MAY BECOME MORE FAVORED AS LOW-LEVEL THERMAL PROFILES
COOL. THE EXTENT TO WHICH IT OCCURS IS STILL NOT CLEAR BUT AREAS
ALONG THE COOK COUNTY IL SHORE SEEM MOST FAVORED INTO MID
AFTERNOON BEFORE IT PIVOTS INTO NORTHWEST INDIANA LATE THIS
AFTERNOON/EARLY THIS EVENING.
MDB
//PREV DISCUSSION...
1110 AM CST
HAVE OPTED TO UPGRADE THE WINTER WEATHER ADVISORY TO A WINTER
STORM WARNING FOR MUCH OF NORTHEAST IL AND NORTHWEST IN. RADAR
TRENDS SHOW THE MAIN BAND OF SNOW INTENSIFYING AND BECOMING MORE
WIDESPREAD ACROSS MUCH OF THE FORECAST AREA AS IT LIFT
NORTHEASTWARD AND BEGINS TO PIVOT COUNTER-CLOCKWISE.
FRONTOGENETICAL FORCING BECOME BETTER FOCUSED AS MID LEVEL TROUGH
SWINGS ACROSS THE AREA BRINGING IN WARM ADVECTION FROM THE EAST
AND COLD ADVECTION FROM THE WEST. IN ADDITION...FOCUSING MAY BE
FURTHER ENHANCED BY THE PRESENCE OF A MID LEVEL TROUGH OF WARM AIR
ALOFT. THIS SYNOPTIC FORCING BY ITSELF SUGGESTS THAT SNOWFALL
RATES WILL BE HIGHER FROM MID AFTERNOON THROUGH EARLY EVENING
RESULTING IN 4-8 INCH TOTALS IN A SHORTER AMOUNT OF TIME. IN
ADDITION LAKE ENHANCEMENT IN SOME FORM STILL LOOKS POSSIBLE LATE
THIS AFTERNOON...BUT WILL BE VERY CHALLENGING TO PIN DOWN. SURFACE
OBS AROUND THE SOUTHERN SHORE STILL SHOW SIGNS OF A CIRCULATION
WITH RADAR SHOWING A NORTHWEST-SOUTHEAST ORIENTED BAND OF PRECIP
WHICH MAY BE REFLECTIVE MORE OF A ELONGATED CONVERGENCE AREA.
SEVERAL RECENT RUNS OF THE RUC/HRRR SHOW A CLOSED CIRCULATION
SHIFTING WESTWARD TOWARD THE IL SHORE THIS AFTERNOON WITH OTHER
GUIDANCE SHOWING AT LEAST SOME SORT OF SHORELINE CONVERGENCE
DEVELOPING. THE CHALLENGE WILL BE FOR THIS TO CONTINUE IN THE
MIDST OF INCREASING NORTHWESTERLY LOW LEVEL FLOW...WHICH HAS BEEN
SLOWER TO ADVANCE EASTWARD. SHOULD THIS LAKE ENHANCEMENT/BANDING
OCCUR...AND THIS IS STILL UNCERTAIN...THEN SOME AREAS COULD EASILY
SEE 8-10 INCHES OR POSSIBLY MORE BUT THIS WOULD LIKELY BE VERY
LOCALIZED. EVEN WITHOUT LAKE ENHANCEMENT SNOWFALL RATES ARE
EXPECTED TO BE HEAVIEST DURING THE AFTERNOON/EVENING RUSH
HOUR...WITH IMPACTS MAGNIFIED UNDER ANY LAKE BANDS. GUSTY WINDS
WILL SPREAD IN FROM THE WEST THROUGH THE AFTERNOON ACROSS NORTH
CENTRAL ILLINOIS AND INTO THE CHICAGO METRO LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN INTO NW INDIANA.
MDB
//PREV DISCUSSION...
309 AM CST
NEAR TERM (NOW THROUGH FRIDAY)...
VERY LITTLE CHANGE FROM PREVIOUS FORECAST WITH ONLY REAL ADJUSTMENT
BEING UPGRADING TO A WARNING FOR PORTER COUNTY DUE TO SOME LAKE
ENHANCEMENT THIS AFTERNOON POSSIBLY INTO VERY EARLY THIS EVENING.
POTENT VORT MAX EVIDENT ON WATER VAPOR IMAGERY OVER KS EARLY THIS
MORNING WILL CONTINUE TO CHARGE EASTWARD AND RESULT IN ENTIRE TROUGH
AXIS BECOMING INCREASINGLY NEGATIVELY TILTED TODAY INTO TONIGHT. AS
THIS OCCURS THE NORTH-SOUTH AXIS OF LIGHT-MODERATE SNOW EXTENDING
FROM WESTERN WI SOUTH INTO MISSOURI AT 09Z IS LIKELY TO GRADUALLY
BECOME RE-ORIENTED INTO A MORE NW-SE AXIS AS IT SHIFTS SLOWLY
EASTWARD. THE RE-ORIENTATION THATS EXPECTED TO TAKE PLACE WILL
RESULT IN A DECELERATION OF THE EASTWARD PROGRESSION OF THE SNOW
OVER NORTHWEST ILLINOIS AND STILL ANTICIPATE IT BEING LATE MORNING
BEFORE SNOW BREAKS OUT IN METRO CHICAGO AND POSSIBLY NOT TIL MID
MORNING AS FAR WEST AS ROCKFORD.
AS HAS BEEN NOTED FOR A COUPLE DAYS NOW...THE SYSTEM WILL NOT HAVE
AN ABUNDANCE OF MOISTURE TO WORK WITH HOWEVER WHAT IT LACKS IN
MOISTURE IT LOOKS TO MAKE UP FOR IN FORCING AND DURATION. AS THE
INTENSE COMPACT CLOSED LOW PLOWS EAST ITS PROGGED TO DEEPEN TODAY
RESULTING IN VERY IMPRESSIVE 12HR/500MB HEIGHT FALLS OVER 200DM VERY
DEEP MODERATE ASCENT EXPECTED. SYNOPTICALLY STILL APPEARS AS THOUGH
QPF ACROSS THE CWA WILL BE FAIRLY UNIFORM AND SUPPORTIVE OF A SOLID
4-8 INCH SNOWFALL CWA-WIDE. THERMAL PROFILES ARE A BIT WARMER THAN
IN PREVIOUS RUNS RESULTING IN SLIGHTLY LESS FAVORABLY DEEP DENDRITIC
GROWTH ZONE (DGZ) WHICH COULD CUT BACK ON SNOW:LIQUID RATIOS A BIT.
IN ADDITION...THE STRONG WINDS ALSO ARE NOT SUPPORTIVE OF
EXCEPTIONALLY HIGH SNOW:LIQUID RATIOS AND THINK A REASONABLE BALL
PARK GUESS IS THAT THEY WILL GENERALLY END UP IN THE BALLPARK OF
10-15:1.
INTERESTINGLY...SOME OF THE HI-RES MESOSCALE MODELS ARE SUGGESTING
THAT THERE COULD BE SOME MESOSCALE BANDING OF HEAVY SNOW DEVELOPING
BY THIS AFTERNOON OVER PORTIONS OF OUR CWA IN ASSOCIATION WITH
STRENGTHENING LOW LEVEL FRONTOGENETIC CIRCULATION. SHOULD THAT OCCUR
IT WOULD NOT BE AT ALL HARD TO ENVISION A BAND OF SNOWFALL TOTALS IN
8-12 INCH RANGE...PARTICULARLY CLOSE TO PIVOT POINT WHERE HEAVIER
SNOW BAND WILL SIT THE LONGEST AS THE ORIENTATION GOES FROM WNW-ESE
TO MORE NE-SW TONIGHT. REALLY IMPOSSIBLE TO PINPOINT THOSE TYPE OF
MESO-BETA SCALE TYPE PHENOMENA THIS FAR IN ADVANCE SO RATHER THAN
BLANKETING 23 COUNTIES WITH A WARNING WHEN ITD PROBABLY ONLY BE A
FRACTION OF THOSE REACH CRITERIA HAVE OPTED TO LET THE ADVISORY
RIDE WITH 4-8 INCH AMOUNTS AND JUST MENTION LOCALLY HEAVIER TOTALS
IN THE WSW. AS MESOSCALE DETAILS START TO UNFOLD LATER TODAY ITS
POSSIBLE THAT THE DAY SHIFT MAY NEED TO UPGRADE PORTIONS OF THE
ADVISORY TO A WARNING.
HAVE OPTED TO UPGRADE PORTER COUNTY INDIANA TO A WARNING...AS LOW
LEVEL TRAJECTORIES COULD ALLOW FOR A PERIOD OF LAKE ENHANCED
SNOWFALL THIS AFTERNOON. THE WINDOW OF OPPORTUNITY FOR LAKE
ENHANCEMENT FOR NE PORTER LOOKS SMALL AS CONDITIONS ARE LIKELY TO
BECOMING INCREASINGLY SUPPORTIVE OF LAKE ENHANCEMENT THIS AFTERNOON
BUT AT THE SAME TIME WINDS WILL BE BACKING WHICH SHOULD SENDING ANY
THREAT OF LAKE ENHANCEMENT EAST INTO IWX-LAND. BEFORE THAT OCCURS
SEEMS PLAUSIBLE THAT THE OCCURS COULD EASILY SEE NE PORTER PICKING
UP A COUPLE BONUS INCHES OF SNOW OFF THE LAKE.
SNOW LOOKS TO START WINDING DOWN AFTER MIDNIGHT AND ENDING
EVERYWHERE BY MID-LATE MORNING FRIDAY. NO CHANGES PLANNED TO THE
TIMING OF THE HEADLINES. WITH WINDS LIKELY TO GUST TO OVER 30 MPH
THIS AFTERNOON AND TONIGHT BLOWING AND DRIFTING SNOW WILL LIKELY BE
AN ISSUE WITH THIS STORM...PARTICULARLY TONIGHT AS SNOW BECOMES
FLUFFIER INCREASING ITS "BLOW-ABILITY".
IZZI
IN-BETWEEN TERM (FRIDAY NIGHT THROUGH SATURDAY NIGHT)...
IN THE WAKE OF THE STORM FOCUS WILL TURN TO TEMPS FRIDAY
NIGHT...WHICH WILL ULTIMATELY BE CLOSELY TIED TO HOW MUCH (IF ANY
CLEARING) WE SEE. MODELS ALL SUGGEST THAT STRATUS WILL CLEAR OUT
FRIDAY EVENING...BUT MODELS ARE ALSO NOTORIOUS FOR BREAKING STRATUS
UP TOO QUICKLY. SUSPECT THAT THERE IS A VERY REAL CHANCE THAT THE
STRATUS MAY NOT CLEAR OUT AT ALL BEFORE CLOUDINESS WITH SATURDAY`S
CLIPPER ARRIVES LATE FRIDAY NIGHT INTO SAT MORNING. GIVEN THE LOW
CONFIDENCE AT THIS DISTANCE HAVE TAKEN A CONSERVATIVE/MIDDLE OF THE
ROAD APPROACH TO TEMPS. ON THE ONE EXTREME...IF SKIES CLEAR OUT
WITH THE SURFACE RIDGE AXIS APPROACHING ITS A VERY REAL
POSSIBILITY THAT LOWS COULD DROP TO BETWEEN ZERO TO
-10...PARTICULARLY OVER NORTH CENTRAL ILLINOIS. CONVERSELY...IF
STRATUS HANGS ON TEMPS MAY END UP MOST IN THE LOW TO MID
TEENS...WHICH I SUSPECT IS PROBABLY THE MORE LIKELY SCENARIO.
BY SATURDAY A FAST MOVING CLIPPER IS PROGGED TO ZIP SOUTHEASTWARD
ACROSS THE MIDWEST. NOT AN OVERLY STRONG SYSTEM AND WILL BE MOISTURE
STARVED...BUT WITH PERSISTENT WARM AIR ADVECTION MIGHT BE ABLE TO
LAY DOWN A BAND OF AN INCH OR SO OF SNOW. MODELS GENERALLY TRACK
SURFACE LOW FROM NORTHERN IOWA INTO SOUTHERN ILLINOIS WHICH WOULD
FAVOR OUR WESTERN CWA FOR HIGHEST CHANCES OF SNOW. HAVE TRENDED POPS
UP IN THE GRIDS AGAIN...WELL ABOVE MOS GUIDANCE AND MORE IN LINE
WITH HPC QPF FORECAST OF GREATER THAN A TENTH OF AN INCH. CLIPPER
SHOULD BE OUT OF THE AREA BY LATER SATURDAY EVENING WITH CLOUDS
PROBABLY STICKING AROUND AND KEEPING TEMPS SOMEWHAT IN CHECK
SATURDAY NIGHT.
IZZI
LONG TERM (SUNDAY THROUGH WEDNESDAY)...
THE POLAR JET WHICH HAD BEEN ANCHORED TO OUR NORTH MUCH OF THE
WINTER WILL BE MORE PRESENT OVER THE MID-SECTION OF THE COUNTRY.
THIS SEEMS TIED TO A MORE ORGANIZED POLAR VORTEX DEVELOPING OVER
NORTHERN CANADA/BAFFIN ISLAND...A FEATURE CONDUCIVE FOR STEERING
COLD AIR PERIODS INTO CENTRAL CANADA AND OFTEN THE EASTERN HALF OF
THE U.S. THAT SAID...A RECOVERY FROM OUR IMMEDIATE COLD AIR SNAP
WILL BE SEEN AT THE START OF NEXT WEEK WITH 850 MB TEMPERATURES
RETURNING TO ABOVE ZERO BY MONDAY WITHIN DEEP SOUTHWEST FLOW. THE
PATTERN ACTUALLY WILL BRIEFLY RESEMBLE MUCH OF THE PAST
MONTH...HOWEVER ANTICIPATED SNOW COVER ON THE GROUND THROUGHOUT THE
REGION SHOULD KEEP THE NEAR-SURFACE AIR MASS COOLER THAN WHAT WE
HAVE SEEN RECENTLY WITH THE SAME TYPE OF AIR MASS. IN
ADDITION...MORE COLUMN MOISTURE IS PROJECTED IN ALL LONG RANGE
GUIDANCE DURING MONDAY...A HINT AT STRATUS WHICH WOULD BE MORE
FAVORED WITH MOIST AND MILD RETURN FLOW OVER SNOW COVER. HAVE GUIDED
MORE TOWARDS A BLEND OF RAW GUIDANCE FOR HIGHS AS OPPOSED TO THE
BIAS-CORRECTED WHICH HAS WORKED SO WELL FOR HIGH TEMPERATURES THE
PAST MONTH TO MONTH AND A HALF. FOR SUN NIGHT AND MON NIGHT HAVE
TRENDED TOWARDS THE MILDER BIAS-CORRECTED FORECASTS.
A COLD FRONT IS EXPECTED TO WORK THROUGH SOMETIME MONDAY NIGHT OR
TUESDAY...WITH A POTENTIAL LOW DEVELOPING ALONG IT DURING THAT
PERIOD. A MEAN SOLUTION ON THE MODELS HAS A LOW TRACKING NEAR OR
JUST TO THE WEST OF THE AREA. THIS WOULD AT LEAST INTRODUCE
THICKNESSES SUPPORTIVE OF RAIN/DRIZZLE DURING MONDAY AND MONDAY
NIGHT IN ANY PRECIPITATION THAT FALLS...AND THE CHANCE FOR
POTENTIALLY RAIN CHANGING TO SNOW LATER ON. SLOWER HAS BEEN BETTER
WITH SYSTEMS RECENTLY...AND THE 12.00 EC SLOWED EVEN FURTHER FROM
ITS PRECEDING RUN. CONFIDENCE IN THIS PERIOD IS LOW THOUGH WITH A
LOW DEVELOPING ALONG A FRONT WITH A SYSTEM THAT IS STILL WELL
OFFSHORE THE WEST COAST. INTERESTINGLY ENOUGH...DEW POINTS ARE
FORECAST TO CREEP UP TO THE MID 30S TO POSSIBLY LOWER 40S IN THE
FORECAST AREA...WHICH COMBINED WITH ANY RAIN/DRIZZLE WOULD LEAD TO
QUICK SNOW MELT AND POSSIBLY ADVECTION FOG.
BEYOND...BOTH THE 12.00 GFS AND EC HAVE THE NEXT COLD AIR DOME BUILT
IN SOUTHERN CANADA BY MIDWEEK WITH 850 MB TEMPS OF -30C OR COLDER.
THEY BOTH DIFFER VASTLY FROM RUN TO RUN IN HOW FAR SOUTH AND EAST
AND HOW QUICKLY THIS EVOLVES...AND WHETHER OR NOT IT WILL EVEN GET
HERE. THE JET LOOKS TO REMAIN ACTIVE AS WELL...SO CONFIDENCE IN THIS
PERIOD IS LOW.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WEST/NORTHWEST WINDS SLOWLY INCREASING THROUGH THE REMAINDER OF
THE AFTERNOON WITH THE STRONGER GUSTS EXPECTED LATE THIS
AFTERNOON/EARLY EVENING.
* PREVAILING IFR CEILINGS STILL EXPECTED THROUGH THE REMAINDER OF
THE DAY/NIGHT.
* LIGHT TO MODERATE SNOW TO CONTINUE THIS AFTERNOON WITH PERIODS
OF HEAVIER SNOW STILL POSSIBLE. VIS OF 1/2SM EXPECTED WITH
PERIODS OF 1/4SM.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
LARGE AREA OF LIGHT TO MODERATE SNOW CONTINUES TO DEVELOP AND
SLOWLY MOVE ACROSS THE TERMINALS EARLY THIS AFTERNOON AS LARGE
SCALE FORCING MOVES THROUGH THE REGION. EXPECT THIS LIGHT TO
MODERATE SNOW TO PERSIST INTO THE AFTERNOON AND EVEN EXPECT AN
INCREASE IN INTENSITY WITH PERIODS OF HEAVY SNOW POSSIBLE. VIS
LOOKS TO HOLD AROUND 1/2SM WITH PERIODS OF 1/4SM POSSIBLE LATER
THIS AFTERNOON. THIS PERIOD OF HEAVIER SNOW IS EXPECTED TO
CONTINUE INTO THE EARLY AFTERNOON AND EARLY EVENING WITH SNOWFALL
RATES ALSO BECOMING AN ISSUE. LATER THIS EVENING...LIGHT TO
MODERATE SNOW CAN STILL BE EXPECTED WITH SOME UNCERTAINTY AS TO IF
ANOTHER PERIOD OF HEAVIER SNOW COULD BE OBSERVED. WILL CONTINUE TO
MONITOR LATEST TRENDS AND ADJUST ACCORDINGLY FOR THE EARLY EVENING
TIME FRAME. THEN EXPECT THE HEAVIEST SNOW TO START SHIFTING EAST
LATE IN THE EVENING. CEILINGS ARE LOCKED IN AT IFR AND WILL REMAIN
FOR THE REMAINDER OF TODAY AND TONIGHT...BEFORE A SLOW UPWARD
TRENDS TO MVFR BY MID TO LATE MORNING ON FRIDAY AS THIS SYSTEM
SLOWLY TRANSITIONS TO THE EAST.
WEST/NORTHWEST WINDS HAVE BEEN SLOW TO INCREASE TODAY BUT STILL
EXPECT THEM TO INCREASE LATER THIS AFTERNOON AND EVENING.
WINDS/GUSTS WILL INCREASE TO AROUND THE 25KT RANGE DURING THAT
TIME WITH A MORE NORTHWEST WIND EXPECTED AS SURFACE TROUGH PUSHES
THROUGH. WEST/NORTHWEST WINDS WILL THEN SLOWLY DIMINISH FRIDAY
MORNING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH CEILINGS AND TRENDS TODAY/TONIGHT.
* MEDIUM HIGH CONFIDENCE WITH SNOW/VIS TRENDS TODAY...WITH MEDIUM
CONFIDENCE OF SNOW/VIS TRENDS TONIGHT INTO EARLY FRIDAY MORNING.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...CHANCE OF SNOW WITH MVFR OR IFR CIGS/VIS DEVELOPING BY
THE AFTERNOON AND CONTINUING INTO THE NIGHT.
SUNDAY...VFR. WX NIL.
MONDAY...IFR CIGS/VIS IN DRIZZLE OR LIGHT RAIN.
TUESDAY...CHANCE OF SNOW WITH MVFR CIGS/VIS.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
309 AM CST
A LOW PRESSURE SYSTEM OVER OHIO WILL MOVE INTO MICHIGAN THIS
AFTERNOON AND STRENGTHEN. IN ADDITION...ARCTIC AIR WILL POUR INTO
THE REGION TODAY. BETWEEN THESE TWO COMPONENTS...LOW END GALES WILL
FORM ACROSS LAKE MICHIGAN TODAY. WINDS WILL BE NORTH TO NORTHWEST
ALONG THE LAKE...THEREFORE EXPECTING GALES TO LEAK INTO THE INDIANA
NEARSHORE ZONES AS WELL. UPGRADED THE GALE WATCH TO A GALE WARNING
WITH THIS ISSUANCE. THE LOW QUICKLY MOVES EASTWARD FRIDAY AND HIGH
PRESSURE MOVES IN BEHIND IT FRIDAY NIGHT INTO SATURDAY. WINDS WILL
BECOME WESTERLY AND DIMINISH QUICKLY BEHIND THE LOW...BUT EXPECTING
HIGH WAVES TO PERSIST THROUGH EARLY FRIDAY NIGHT IN THE NEARSHORE
ZONES. A WEAKENING LOW PRESSURE SYSTEM PASSES SOUTH OF THE LAKE
LATE SATURDAY...AND WILL HAVE LITTLE TO NO IMPACT ON THE LAKE.
WINDS REMAIN WEAK THROUGH THE WEEKEND BUT BEGIN TO TURN SOUTHERLY
AND INCREASE SUNDAY EVENING AS THE PRESSURE GRADIENT INCREASES
BETWEEN HIGH PRESSURE OVER THE ATLANTIC COAST AND A DEVELOPING LOW
PRESSURE SYSTEM OVER MANITOBA.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-ILZ020-
ILZ022 UNTIL 9 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-
ILZ019-ILZ021-ILZ032 UNTIL 4 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ023-ILZ033-ILZ039 UNTIL 9 AM FRIDAY.
IN...WINTER STORM WARNING...INZ001-INZ002 UNTIL 9 AM FRIDAY.
WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019 UNTIL 9 AM FRIDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL
MIDNIGHT SATURDAY.
GALE WARNING...LMZ744-LMZ745...9 PM THURSDAY TO 3 PM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 9 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
139 PM CST THU JAN 12 2012
.DISCUSSION...
134 PM CST
LIGHT TO MODERATE SNOWFALL CONTINUES ACROSS THE AREA EARLY THIS
AFTERNOON. RADAR TRENDS AND SHORT TERM GUIDANCE SHOW TWO AREAS OF
BETTER FORCING WITHIN THE BROAD LIFT. THE FIRST IS ORIENTED FROM
BENTON HARBOR MICHIGAN NORTHWEST ACROSS MILWAUKEE WITH A SECOND
STARTING TO TAKE SHAPE FROM RENSSELAER TO PRINCETON TO SAVANNA. IN
BETWEEN...RADAR RETURNS HAVE EASED OFF SOMEWHAT BUT SNOWFALL
CONTINUES. OVERALL NEAR TERM TRENDS SUGGEST THAT
FORCING/FRONTOGENESIS WILL BECOME MORE FOCUSED OVER THE CWA INTO
LATE AFTERNOON...WITH PERHAPS THE MOST FOCUSED FORCING OVER NE
IL/NW IN EARLY THIS EVENING.
IN ADDITION...LOW LEVEL AREA OF CONVERGENCE OVER THE LAKE
CONTINUES TO COMPLICATE NEAR TERM DETAILS. LATEST RUC SHOWS AN
EAST-WEST BAND OF CONVERGENCE FROM THE LAKE/COOK IL BORDER
EASTWARD. THIS TROUGH IS NOT SO EVIDENT IN SHORE OBS BUT ORD TDWR
SHOWS A SOUTHWESTWARD MOVING AREA OF ENHANCED REFLECTIVITY MOVING
INLAND FROM EVANSTON SOUTHWARD INTO DOWNTOWN CHICAGO. LAKE
INFLUENCE WILL LIKELY BE RATHER TRANSIENT BUT IS SEEMINGLY ABLE TO
OCCUR...AND MAY BECOME MORE FAVORED AS LOW-LEVEL THERMAL PROFILES
COOL. THE EXTENT TO WHICH IT OCCURS IS STILL NOT CLEAR BUT AREAS
ALONG THE COOK COUNTY IL SHORE SEEM MOST FAVORED INTO MID
AFTERNOON BEFORE IT PIVOTS INTO NORTHWEST INDIANA LATE THIS
AFTERNOON/EARLY THIS EVENING.
MDB
&&
.PREV DISCUSSION...
1110 AM CST
HAVE OPTED TO UPGRADE THE WINTER WEATHER ADVISORY TO A WINTER
STORM WARNING FOR MUCH OF NORTHEAST IL AND NORTHWEST IN. RADAR
TRENDS SHOW THE MAIN BAND OF SNOW INTENSIFYING AND BECOMING MORE
WIDESPREAD ACROSS MUCH OF THE FORECAST AREA AS IT LIFT
NORTHEASTWARD AND BEGINS TO PIVOT COUNTER-CLOCKWISE.
FRONTOGENETICAL FORCING BECOME BETTER FOCUSED AS MID LEVEL TROUGH
SWINGS ACROSS THE AREA BRINGING IN WARM ADVECTION FROM THE EAST
AND COLD ADVECTION FROM THE WEST. IN ADDITION...FOCUSING MAY BE
FURTHER ENHANCED BY THE PRESENCE OF A MID LEVEL TROUGH OF WARM AIR
ALOFT. THIS SYNOPTIC FORCING BY ITSELF SUGGESTS THAT SNOWFALL
RATES WILL BE HIGHER FROM MID AFTERNOON THROUGH EARLY EVENING
RESULTING IN 4-8 INCH TOTALS IN A SHORTER AMOUNT OF TIME. IN
ADDITION LAKE ENHANCEMENT IN SOME FORM STILL LOOKS POSSIBLE LATE
THIS AFTERNOON...BUT WILL BE VERY CHALLENGING TO PIN DOWN. SURFACE
OBS AROUND THE SOUTHERN SHORE STILL SHOW SIGNS OF A CIRCULATION
WITH RADAR SHOWING A NORTHWEST-SOUTHEAST ORIENTED BAND OF PRECIP
WHICH MAY BE REFLECTIVE MORE OF A ELONGATED CONVERGENCE AREA.
SEVERAL RECENT RUNS OF THE RUC/HRRR SHOW A CLOSED CIRCULATION
SHIFTING WESTWARD TOWARD THE IL SHORE THIS AFTERNOON WITH OTHER
GUIDANCE SHOWING AT LEAST SOME SORT OF SHORELINE CONVERGENCE
DEVELOPING. THE CHALLENGE WILL BE FOR THIS TO CONTINUE IN THE
MIDST OF INCREASING NORTHWESTERLY LOW LEVEL FLOW...WHICH HAS BEEN
SLOWER TO ADVANCE EASTWARD. SHOULD THIS LAKE ENHANCEMENT/BANDING
OCCUR...AND THIS IS STILL UNCERTAIN...THEN SOME AREAS COULD EASILY
SEE 8-10 INCHES OR POSSIBLY MORE BUT THIS WOULD LIKELY BE VERY
LOCALIZED. EVEN WITHOUT LAKE ENHANCEMENT SNOWFALL RATES ARE
EXPECTED TO BE HEAVIEST DURING THE AFTERNOON/EVENING RUSH
HOUR...WITH IMPACTS MAGNIFIED UNDER ANY LAKE BANDS. GUSTY WINDS
WILL SPREAD IN FROM THE WEST THROUGH THE AFTERNOON ACROSS NORTH
CENTRAL ILLINOIS AND INTO THE CHICAGO METRO LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN INTO NW INDIANA.
MDB
//PREV DISCUSSION...
309 AM CST
NEAR TERM (NOW THROUGH FRIDAY)...
VERY LITTLE CHANGE FROM PREVIOUS FORECAST WITH ONLY REAL ADJUSTMENT
BEING UPGRADING TO A WARNING FOR PORTER COUNTY DUE TO SOME LAKE
ENHANCEMENT THIS AFTERNOON POSSIBLY INTO VERY EARLY THIS EVENING.
POTENT VORT MAX EVIDENT ON WATER VAPOR IMAGERY OVER KS EARLY THIS
MORNING WILL CONTINUE TO CHARGE EASTWARD AND RESULT IN ENTIRE TROUGH
AXIS BECOMING INCREASINGLY NEGATIVELY TILTED TODAY INTO TONIGHT. AS
THIS OCCURS THE NORTH-SOUTH AXIS OF LIGHT-MODERATE SNOW EXTENDING
FROM WESTERN WI SOUTH INTO MISSOURI AT 09Z IS LIKELY TO GRADUALLY
BECOME RE-ORIENTED INTO A MORE NW-SE AXIS AS IT SHIFTS SLOWLY
EASTWARD. THE RE-ORIENTATION THATS EXPECTED TO TAKE PLACE WILL
RESULT IN A DECELERATION OF THE EASTWARD PROGRESSION OF THE SNOW
OVER NORTHWEST ILLINOIS AND STILL ANTICIPATE IT BEING LATE MORNING
BEFORE SNOW BREAKS OUT IN METRO CHICAGO AND POSSIBLY NOT TIL MID
MORNING AS FAR WEST AS ROCKFORD.
AS HAS BEEN NOTED FOR A COUPLE DAYS NOW...THE SYSTEM WILL NOT HAVE
AN ABUNDANCE OF MOISTURE TO WORK WITH HOWEVER WHAT IT LACKS IN
MOISTURE IT LOOKS TO MAKE UP FOR IN FORCING AND DURATION. AS THE
INTENSE COMPACT CLOSED LOW PLOWS EAST ITS PROGGED TO DEEPEN TODAY
RESULTING IN VERY IMPRESSIVE 12HR/500MB HEIGHT FALLS OVER 200DM VERY
DEEP MODERATE ASCENT EXPECTED. SYNOPTICALLY STILL APPEARS AS THOUGH
QPF ACROSS THE CWA WILL BE FAIRLY UNIFORM AND SUPPORTIVE OF A SOLID
4-8 INCH SNOWFALL CWA-WIDE. THERMAL PROFILES ARE A BIT WARMER THAN
IN PREVIOUS RUNS RESULTING IN SLIGHTLY LESS FAVORABLY DEEP DENDRITIC
GROWTH ZONE (DGZ) WHICH COULD CUT BACK ON SNOW:LIQUID RATIOS A BIT.
IN ADDITION...THE STRONG WINDS ALSO ARE NOT SUPPORTIVE OF
EXCEPTIONALLY HIGH SNOW:LIQUID RATIOS AND THINK A REASONABLE BALL
PARK GUESS IS THAT THEY WILL GENERALLY END UP IN THE BALLPARK OF
10-15:1.
INTERESTINGLY...SOME OF THE HI-RES MESOSCALE MODELS ARE SUGGESTING
THAT THERE COULD BE SOME MESOSCALE BANDING OF HEAVY SNOW DEVELOPING
BY THIS AFTERNOON OVER PORTIONS OF OUR CWA IN ASSOCIATION WITH
STRENGTHENING LOW LEVEL FRONTOGENETIC CIRCULATION. SHOULD THAT OCCUR
IT WOULD NOT BE AT ALL HARD TO ENVISION A BAND OF SNOWFALL TOTALS IN
8-12 INCH RANGE...PARTICULARLY CLOSE TO PIVOT POINT WHERE HEAVIER
SNOW BAND WILL SIT THE LONGEST AS THE ORIENTATION GOES FROM WNW-ESE
TO MORE NE-SW TONIGHT. REALLY IMPOSSIBLE TO PINPOINT THOSE TYPE OF
MESO-BETA SCALE TYPE PHENOMENA THIS FAR IN ADVANCE SO RATHER THAN
BLANKETING 23 COUNTIES WITH A WARNING WHEN ITD PROBABLY ONLY BE A
FRACTION OF THOSE REACH CRITERIA HAVE OPTED TO LET THE ADVISORY
RIDE WITH 4-8 INCH AMOUNTS AND JUST MENTION LOCALLY HEAVIER TOTALS
IN THE WSW. AS MESOSCALE DETAILS START TO UNFOLD LATER TODAY ITS
POSSIBLE THAT THE DAY SHIFT MAY NEED TO UPGRADE PORTIONS OF THE
ADVISORY TO A WARNING.
HAVE OPTED TO UPGRADE PORTER COUNTY INDIANA TO A WARNING...AS LOW
LEVEL TRAJECTORIES COULD ALLOW FOR A PERIOD OF LAKE ENHANCED
SNOWFALL THIS AFTERNOON. THE WINDOW OF OPPORTUNITY FOR LAKE
ENHANCEMENT FOR NE PORTER LOOKS SMALL AS CONDITIONS ARE LIKELY TO
BECOMING INCREASINGLY SUPPORTIVE OF LAKE ENHANCEMENT THIS AFTERNOON
BUT AT THE SAME TIME WINDS WILL BE BACKING WHICH SHOULD SENDING ANY
THREAT OF LAKE ENHANCEMENT EAST INTO IWX-LAND. BEFORE THAT OCCURS
SEEMS PLAUSIBLE THAT THE OCCURS COULD EASILY SEE NE PORTER PICKING
UP A COUPLE BONUS INCHES OF SNOW OFF THE LAKE.
SNOW LOOKS TO START WINDING DOWN AFTER MIDNIGHT AND ENDING
EVERYWHERE BY MID-LATE MORNING FRIDAY. NO CHANGES PLANNED TO THE
TIMING OF THE HEADLINES. WITH WINDS LIKELY TO GUST TO OVER 30 MPH
THIS AFTERNOON AND TONIGHT BLOWING AND DRIFTING SNOW WILL LIKELY BE
AN ISSUE WITH THIS STORM...PARTICULARLY TONIGHT AS SNOW BECOMES
FLUFFIER INCREASING ITS "BLOW-ABILITY".
IZZI
IN-BETWEEN TERM (FRIDAY NIGHT THROUGH SATURDAY NIGHT)...
IN THE WAKE OF THE STORM FOCUS WILL TURN TO TEMPS FRIDAY
NIGHT...WHICH WILL ULTIMATELY BE CLOSELY TIED TO HOW MUCH (IF ANY
CLEARING) WE SEE. MODELS ALL SUGGEST THAT STRATUS WILL CLEAR OUT
FRIDAY EVENING...BUT MODELS ARE ALSO NOTORIOUS FOR BREAKING STRATUS
UP TOO QUICKLY. SUSPECT THAT THERE IS A VERY REAL CHANCE THAT THE
STRATUS MAY NOT CLEAR OUT AT ALL BEFORE CLOUDINESS WITH SATURDAY`S
CLIPPER ARRIVES LATE FRIDAY NIGHT INTO SAT MORNING. GIVEN THE LOW
CONFIDENCE AT THIS DISTANCE HAVE TAKEN A CONSERVATIVE/MIDDLE OF THE
ROAD APPROACH TO TEMPS. ON THE ONE EXTREME...IF SKIES CLEAR OUT
WITH THE SURFACE RIDGE AXIS APPROACHING ITS A VERY REAL
POSSIBILITY THAT LOWS COULD DROP TO BETWEEN ZERO TO
-10...PARTICULARLY OVER NORTH CENTRAL ILLINOIS. CONVERSELY...IF
STRATUS HANGS ON TEMPS MAY END UP MOST IN THE LOW TO MID
TEENS...WHICH I SUSPECT IS PROBABLY THE MORE LIKELY SCENARIO.
BY SATURDAY A FAST MOVING CLIPPER IS PROGGED TO ZIP SOUTHEASTWARD
ACROSS THE MIDWEST. NOT AN OVERLY STRONG SYSTEM AND WILL BE MOISTURE
STARVED...BUT WITH PERSISTENT WARM AIR ADVECTION MIGHT BE ABLE TO
LAY DOWN A BAND OF AN INCH OR SO OF SNOW. MODELS GENERALLY TRACK
SURFACE LOW FROM NORTHERN IOWA INTO SOUTHERN ILLINOIS WHICH WOULD
FAVOR OUR WESTERN CWA FOR HIGHEST CHANCES OF SNOW. HAVE TRENDED POPS
UP IN THE GRIDS AGAIN...WELL ABOVE MOS GUIDANCE AND MORE IN LINE
WITH HPC QPF FORECAST OF GREATER THAN A TENTH OF AN INCH. CLIPPER
SHOULD BE OUT OF THE AREA BY LATER SATURDAY EVENING WITH CLOUDS
PROBABLY STICKING AROUND AND KEEPING TEMPS SOMEWHAT IN CHECK
SATURDAY NIGHT.
IZZI
LONG TERM (SUNDAY THROUGH WEDNESDAY)...
THE POLAR JET WHICH HAD BEEN ANCHORED TO OUR NORTH MUCH OF THE
WINTER WILL BE MORE PRESENT OVER THE MID-SECTION OF THE COUNTRY.
THIS SEEMS TIED TO A MORE ORGANIZED POLAR VORTEX DEVELOPING OVER
NORTHERN CANADA/BAFFIN ISLAND...A FEATURE CONDUCIVE FOR STEERING
COLD AIR PERIODS INTO CENTRAL CANADA AND OFTEN THE EASTERN HALF OF
THE U.S. THAT SAID...A RECOVERY FROM OUR IMMEDIATE COLD AIR SNAP
WILL BE SEEN AT THE START OF NEXT WEEK WITH 850 MB TEMPERATURES
RETURNING TO ABOVE ZERO BY MONDAY WITHIN DEEP SOUTHWEST FLOW. THE
PATTERN ACTUALLY WILL BRIEFLY RESEMBLE MUCH OF THE PAST
MONTH...HOWEVER ANTICIPATED SNOW COVER ON THE GROUND THROUGHOUT THE
REGION SHOULD KEEP THE NEAR-SURFACE AIR MASS COOLER THAN WHAT WE
HAVE SEEN RECENTLY WITH THE SAME TYPE OF AIR MASS. IN
ADDITION...MORE COLUMN MOISTURE IS PROJECTED IN ALL LONG RANGE
GUIDANCE DURING MONDAY...A HINT AT STRATUS WHICH WOULD BE MORE
FAVORED WITH MOIST AND MILD RETURN FLOW OVER SNOW COVER. HAVE GUIDED
MORE TOWARDS A BLEND OF RAW GUIDANCE FOR HIGHS AS OPPOSED TO THE
BIAS-CORRECTED WHICH HAS WORKED SO WELL FOR HIGH TEMPERATURES THE
PAST MONTH TO MONTH AND A HALF. FOR SUN NIGHT AND MON NIGHT HAVE
TRENDED TOWARDS THE MILDER BIAS-CORRECTED FORECASTS.
A COLD FRONT IS EXPECTED TO WORK THROUGH SOMETIME MONDAY NIGHT OR
TUESDAY...WITH A POTENTIAL LOW DEVELOPING ALONG IT DURING THAT
PERIOD. A MEAN SOLUTION ON THE MODELS HAS A LOW TRACKING NEAR OR
JUST TO THE WEST OF THE AREA. THIS WOULD AT LEAST INTRODUCE
THICKNESSES SUPPORTIVE OF RAIN/DRIZZLE DURING MONDAY AND MONDAY
NIGHT IN ANY PRECIPITATION THAT FALLS...AND THE CHANCE FOR
POTENTIALLY RAIN CHANGING TO SNOW LATER ON. SLOWER HAS BEEN BETTER
WITH SYSTEMS RECENTLY...AND THE 12.00 EC SLOWED EVEN FURTHER FROM
ITS PRECEDING RUN. CONFIDENCE IN THIS PERIOD IS LOW THOUGH WITH A
LOW DEVELOPING ALONG A FRONT WITH A SYSTEM THAT IS STILL WELL
OFFSHORE THE WEST COAST. INTERESTINGLY ENOUGH...DEW POINTS ARE
FORECAST TO CREEP UP TO THE MID 30S TO POSSIBLY LOWER 40S IN THE
FORECAST AREA...WHICH COMBINED WITH ANY RAIN/DRIZZLE WOULD LEAD TO
QUICK SNOW MELT AND POSSIBLY ADVECTION FOG.
BEYOND...BOTH THE 12.00 GFS AND EC HAVE THE NEXT COLD AIR DOME BUILT
IN SOUTHERN CANADA BY MIDWEEK WITH 850 MB TEMPS OF -30C OR COLDER.
THEY BOTH DIFFER VASTLY FROM RUN TO RUN IN HOW FAR SOUTH AND EAST
AND HOW QUICKLY THIS EVOLVES...AND WHETHER OR NOT IT WILL EVEN GET
HERE. THE JET LOOKS TO REMAIN ACTIVE AS WELL...SO CONFIDENCE IN THIS
PERIOD IS LOW.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WEST/NORTHWEST WINDS BECOMING MORE NORTHWEST AND SLOWLY
INCREASING THROUGH THE EARLY AFTERNOON WITH THE STRONGER GUSTS
NOT EXPECTED UNTIL LATE THIS AFTERNOON/EARLY EVENING.
* IFR CEILINGS THROUGH THE REMAINDER OF THE DAY/NIGHT.
* LIGHT TO MODERATE SNOW TO CONTINUE THIS AFTERNOON WITH SNOW
EXPECTED TO INCREASE LATER THIS AFTERNOON WITH PERIODS OF HEAVY
SNOW POSSIBLE. VIS OF 1/2SM EXPECTED WITH PERIODS OF 1/4SM.
* LIGHT SNOW TO SLOWLY DIMINISH TONIGHT INTO EARLY FRIDAY MORNING
WITH VIS SLOWLY IMPROVING.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
LARGE AREA OF LIGHT TO MODERATE SNOW CONTINUES TO DEVELOP AND
SLOWLY MOVE ACROSS THE TERMINALS EARLY THIS AFTERNOON AS LARGE
SCALE FORCING MOVES THROUGH THE REGION. EXPECT THIS LIGHT TO
MODERATE SNOW TO PERSIST INTO THE AFTERNOON AND EVEN EXPECT AN
INCREASE IN INTENSITY WITH PERIODS OF HEAVY SNOW POSSIBLE. VIS
LOOKS TO HOLD AROUND 1/2SM WITH PERIODS OF 1/4SM POSSIBLE LATER
THIS AFTERNOON. THIS PERIOD OF HEAVIER SNOW IS EXPECTED TO
CONTINUE INTO THE EARLY AFTERNOON AND EARLY EVENING WITH SNOWFALL
RATES ALSO BECOMING AN ISSUE. LATER THIS EVENING...LIGHT TO
MODERATE SNOW CAN STILL BE EXPECTED WITH SOME UNCERTAINTY AS TO IF
ANOTHER PERIOD OF HEAVIER SNOW COULD BE OBSERVED. WILL CONTINUE TO
MONITOR LATEST TRENDS AND ADJUST ACCORDINGLY FOR THE EARLY EVENING
TIME FRAME. THEN EXPECT THE HEAVIEST SNOW TO START SHIFTING EAST
LATE IN THE EVENING. CEILINGS ARE LOCKED IN AT IFR AND WILL REMAIN
FOR THE REMAINDER OF TODAY AND TONIGHT...BEFORE A SLOW UPWARD
TRENDS TO MVFR BY MID TO LATE MORNING ON FRIDAY AS THIS SYSTEM
SLOWLY TRANSITIONS TO THE EAST.
WEST/NORTHWEST WINDS HAVE BEEN SLOW TO INCREASE TODAY BUT STILL
EXPECT THEM TO INCREASE LATER THIS AFTERNOON AND EVENING.
WINDS/GUSTS WILL INCREASE TO AROUND THE 25KT RANGE DURING THAT
TIME WITH A MORE NORTHWEST WIND EXPECTED AS SURFACE TROUGH PUSHES
THROUGH. WEST/NORTHWEST WINDS WILL THEN SLOWLY DIMINISH FRIDAY
MORNING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* HIGH CONFIDENCE WITH CEILINGS AND TRENDS TODAY/TONIGHT.
* MEDIUM HIGH CONFIDENCE WITH SNOW/VIS TRENDS TODAY...WITH MEDIUM
CONFIDENCE OF SNOW/VIS TRENDS TONIGHT INTO EARLY FRIDAY MORNING.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...CHANCE OF SNOW WITH MVFR OR IFR CIGS/VIS DEVELOPING BY
THE AFTERNOON AND CONTINUING INTO THE NIGHT.
SUNDAY...VFR. WX NIL.
MONDAY...IFR CIGS/VIS IN DRIZZLE OR LIGHT RAIN.
TUESDAY...CHANCE OF SNOW WITH MVFR CIGS/VIS.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
309 AM CST
A LOW PRESSURE SYSTEM OVER OHIO WILL MOVE INTO MICHIGAN THIS
AFTERNOON AND STRENGTHEN. IN ADDITION...ARCTIC AIR WILL POUR INTO
THE REGION TODAY. BETWEEN THESE TWO COMPONENTS...LOW END GALES WILL
FORM ACROSS LAKE MICHIGAN TODAY. WINDS WILL BE NORTH TO NORTHWEST
ALONG THE LAKE...THEREFORE EXPECTING GALES TO LEAK INTO THE INDIANA
NEARSHORE ZONES AS WELL. UPGRADED THE GALE WATCH TO A GALE WARNING
WITH THIS ISSUANCE. THE LOW QUICKLY MOVES EASTWARD FRIDAY AND HIGH
PRESSURE MOVES IN BEHIND IT FRIDAY NIGHT INTO SATURDAY. WINDS WILL
BECOME WESTERLY AND DIMINISH QUICKLY BEHIND THE LOW...BUT EXPECTING
HIGH WAVES TO PERSIST THROUGH EARLY FRIDAY NIGHT IN THE NEARSHORE
ZONES. A WEAKENING LOW PRESSURE SYSTEM PASSES SOUTH OF THE LAKE
LATE SATURDAY...AND WILL HAVE LITTLE TO NO IMPACT ON THE LAKE.
WINDS REMAIN WEAK THROUGH THE WEEKEND BUT BEGIN TO TURN SOUTHERLY
AND INCREASE SUNDAY EVENING AS THE PRESSURE GRADIENT INCREASES
BETWEEN HIGH PRESSURE OVER THE ATLANTIC COAST AND A DEVELOPING LOW
PRESSURE SYSTEM OVER MANITOBA.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ005-ILZ006-ILZ012-ILZ013-ILZ014-ILZ020-
ILZ022 UNTIL 9 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-
ILZ019-ILZ021-ILZ032 UNTIL 4 AM FRIDAY.
WINTER WEATHER ADVISORY...ILZ023-ILZ033-ILZ039 UNTIL 9 AM FRIDAY.
IN...WINTER STORM WARNING...INZ001-INZ002 UNTIL 9 AM FRIDAY.
WINTER WEATHER ADVISORY...INZ010-INZ011-INZ019 UNTIL 9 AM FRIDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL
MIDNIGHT SATURDAY.
GALE WARNING...LMZ744-LMZ745...9 PM THURSDAY TO 3 PM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 9 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
345 PM EST THU JAN 12 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL
INDIANA...USHERING AN ARCTIC AIRMASS INTO CENTRAL INDIANA FOR THE
NEXT FEW DAYS. AN UPPER LEVEL LOW PRESSURE SYSTEM WILL EXIT THE
STATE TONIGHT...HOWEVER...MOISTURE WRAPPING AROUND THE LOW WILL
LIKELY RESULT IN SCATTERED SNOW SHOWERS...PARTICULARLY THIS
EVENING.
THE STRONG LOW WILL LINGER ACROSS THE NORTHEAST UNITED STATE ON
FRIDAY...PROVIDING A COLD...ARCTIC FLOW OF AIR TO CENTRAL INDIANA.
A FEW SNOW SHOWERS CANNOT BE RULED OUT ON FRIDAY.
A QUICK MOVING RIDGE OF HIGH PRESSURE WILL PUSH ACROSS THE STATE
FRIDAY NIGHT AND SATURDAY...PROVIDING MORE COLD...CLOUDY...BUT DRY
WEATHER.
ANOTHER UPPER LEVEL DISTURBANCE WILL PUSH INTO THE STATE FROM THE
NORTHWEST ON SATURDAY NIGHT AND SUNDAY...AND THIS MAY PROVIDE
ANOTHER BRIEF ROUND OF SNOW SHOWERS.
THE COLD AIR IS EXPECTED TO EXIT EARLY NEXT WORK WEEK AS THE FLOW
ALOFT BECOMES MORE WESTERLY USHERING MILD PACIFIC AIR BACK TO THE
OHIO VALLEY.
&&
.NEAR TERM /TONIGHT/...
SURFACE ANALYSIS SHOWS LOW PRESSURE OVER SOUTHERN ONTARIO EARLY
THIS AFTERNOON AND A COLD FRONT STRETCHED SOUTH ACROSS WESTERN
OHIO. MUCH COLDER AIR WAS FOUND ACROSS CENTRAL ILLINOIS AND
WESTERN CENTRAL INDIANA WHERE TEMPERATURES WERE IN THE TEENS.
WATER VAPOR IMAGERY INDICATE THE UPPER LOW OVER SE
MISSOURI...DRIVING EASTWARD. RADAR TRENDS SHOW MUCH DRIER AIR
WRAPPING IN TO THE SYSTEM FROM THE SOUTHWEST. MODELS AGREE THAT
THE UPPER SYSTEM WILL PUSH ACROSS THE STATE TONIGHT...HOWEVER BEST
FORCING IS LOST AFTER 06Z. POTENTIAL VORTICITY MUCH DRIER ARRIVING
ALONG WITH SUBSIDENCE AFTER 06Z...HOWEVER FORECAST SOUNDINGS
CONTINUE TO SUGGEST DEEP SATURATION. ALSO 850MB POTENTIAL
TEMPERATURE SURFACE SHOWS A WEAK TROWAL WORKING ACROSS THE
STATE...BUT EXITING AFTER 06Z. THUS WILL KEEP POPS GOING INTO THE
EVENING HOURS AS FORCING WILL BE FAVORABLE...HOWEVER WILL TAPER
POPS OFF AFTER 06Z AS BEST DYNAMIC SHIFT WELL TO THE NORTHEAST.
GIVEN THE DRY AIR WORKING INTO THE AREA ALONG WITH THE FORCING
ENDING BY 06Z...FEEL THAT SNOW AMOUNTS ARE MORE LIKELY TO END UP
AT THE LOWER END OF THE ADVISORY CRITERIA. AS FOR TEMPS WILL TREND
COOLER THAN MAVMOS GIVEN THE STRONG COLD AIR ADVECTION.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
MODELS REMAIN IN PRETTY GOOD OVERALL AGREEMENT DURING THIS PERIOD
AND WILL USE A BLEND.
BROAD CYCLONIC FLOW WILL REMAIN IN PLACE ON FRIDAY AS THE UPPER
LOW DEPARTS AND FORECAST SOUNDINGS INDICATE DEEP SATURATION BUT
MINIMAL FORCING THROUGH 18Z. SOUNDINGS BEGIN TO DRY OUT AFTER 18Z AS
THE COLD ARCTIC AIR MASS BEGINS TO SETTLE IN. THUS WILL CONTINUE
LOW CHANCE POPS DURING THE MORNING HOURS...BUT TAPER OFF TO A DRY
FORECAST IN THE AFTERNOON AS DRIER AIR ARRIVES. WILL TREND COLDER
THAN MAVMOS FOR HIGHS.
COLD NORTHWEST FLOW WILL PERSIST ALOFT ON FRIDAY NIGHT AND ANOTHER
WEAK DISTURBANCE WILL PUSH ACROSS THE STATE. HOWEVER MOISTURE IS
LIMITED AND NO PRECIP WILL BE EXPECTED. FURTHERMORE WITH A FRESH
SNOW COVER AND 850MB TEMPS THAT HAVE FALLEN TO NEAR -11C...WILL
TREND LOWS COLDER THAN MAVMOS.
ANOTHER STRONGER UPPER DISTURBANCE WILL PUSH INTO THE AREA ON
SATURDAY AND SATURDAY NIGHT. GFS IS MUCH DRIER THAN THE NAM. GIVEN
THE EXPECTED FORCING...FEEL THAT THE NAM HANDLES THE SITUATION
HERE AND LOW POPS APPEAR NEEDED. WITH COLD AIR IN PLACE PRECIP
TYPE WILL BE SNOW AS THIS CLIPPER MOVES THROUGH. AGAIN GIVEN THE
EXPECTED CLOUDS WILL TREND HIGHS ON SATURDAY COLDER THAN MAVMOS
AND STICK CLOSE ON LOWS.
A RIDGE OF HIGH PRESSURE WILL THEN BUILD UP ACROSS CENTRAL INDIANA
ON SUNDAY AS WARM AIR ADVECTION BEGINS AS THE DOME OF COLD AIR
BEGINS TO DEPART TO THE EAST. STRONG SOUTHERLY FLOW WILL SET UP BY
SUNDAY EVENING AS HIGH PRESSURE SETTLES ACROSS APPALACHIA AND A LOW
DEVELOPS OVER THE WESTERN PLAINS STATES. WILL AIM FOR A DRY SUNDAY
ALONG WITH TEMPS WARMER THAN MEXMOS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONGER RANGE MODEL DATA SUGGEST A PROGRESSIVE AND POTENTIALLY
ENERGETIC PATTERN ACROSS THE COUNTRY WITH JET STREAM WINDS PROGGED
IN THE 120-170KT RANGE THROUGHOUT MOST OF THE EXTENDED PERIOD.
ENSEMBLES ARE KEYING ON TWO SYSTEMS...ONE PASSING THROUGH IN THE
EARLY TO MIDDLE PARTS OF NEXT WEEK AND ANOTHER POSSIBLY AROUND
THURSDAY. AT THIS TIME...THE FIRST SYSTEM LOOKS TO BE THE STRONGER
OF THE TWO. WILL CONTINUE WITH POPS FROM MONDAY THROUGH TUESDAY
NIGHT...WITH THE HIGHEST POPS MONDAY NIGHT. JUST ABOUT ALL OF THE
ENSEMBLES TAKE THE SURFACE LOW NORTH OF THE LOCAL AREA...SO THIS
LOOKS TO BE MAINLY A RAIN EVENT...WITH SOME POTENTIAL FOR LIGHT SNOW
NEAR THE END OF THE EVENT.
SYSTEM ON THURSDAY LOOKS TO BE MORE OF A CLIPPER TYPE...AS MAIN
UPPER TROUGH AXIS IS PROGGED TO BE NEAR THE EAST COAST. WILL GO WITH
CHANCE POPS FOR LIGHT SNOW AT THAT TIME.
&&
.AVIATION /DISCUSSION FOR THE 122100Z TAF UPDATES/...
THE HEAVIER SNOW HAS ENDED FOR NOW...SO RAISED THE VISIBILITIES TO
P6SM WITH FLURRIES AND RAISED CEILINGS TO MVFR. GUSTS ARE ALSO
PICKING UP ON CUE SO TWEAKED WITH WINDS JUST A BIT. PREVIOUS
DISCUSSION FOLLOWS...
RADAR TRENDS SUGGEST THE ARRIVAL OF THE SNOW AT KIND MAY BE SOONER
THAN WHAT IS CURRENTLY IN THE FORECAST. WILL NUDGE UP THE ARRIVAL OF
THE SNOW AND ASSOCIATED IFR VISIBILITY RESTRICTIONS TO AROUND
121600Z. UPSTREAM OBSERVATIONS ACROSS ILLINOIS SUGGEST POTENTIAL FOR
A PERIOD OF LIFR VISIBILITY RESTRICTIONS LATER THIS AFTERNOON. MAY
NEED TO ADD THIS IN LATER UPDATES. PREVIOUS DISCUSSION FOLLOWS.
SITES WILL START OFF LOW MVFR OR IFR DUE TO CEILINGS WITH MAINLY
MVFR VISIBILITIES. THESE CONDITIONS SHOULD CONTINUE FOR THE NEXT FEW
HOURS UNTIL SNOW SHOWERS BEGIN TO ARRIVE IN THE WEST AROUND 15Z AND
SPREAD NORTH AND EAST IMPACTING ALL THE SITES BY 18Z. USED TIMING OF
ARRIVAL FROM RUC AND HRRR...WHICH WERE AN HOUR OR SO FASTER THAN THE
VSREFS. WITH SOME ECHOES LOOKING PRETTY STRONG IN THE HRRR FOR THE
INITIAL WAVE OF SNOW THAT MOVES THROUGH DID INCLUDE A TEMPO GROUP OF
LOWER VISIBILITIES. USED THE VSREFS TO COME UP WITH 1 1/2SM FOR ALL
THE SITES FOR A COUPLE OF HOURS AFTER SNOW BEGINS. AFTER THIS
INITIAL SHOT SNOW WILL BE MORE SHOWERY AND ON AND OFF IN NATURE AND
THINK IFR CEILINGS WITH MVFR VISIBILITIES SHOULD COVER THIS WELL.
LATER TONIGHT AROUND 0Z COULD SEE ANOTHER BOUT OF HEAVIER SNOW
SHOWERS AGAIN WITH WIDESPREAD VISIBILITIES AROUND A MILE AND A
HALF...BUT THESE CONDITIONS SHOULD IMPROVE SOMEWHAT AFTER 6Z TO MORE
WIDESPREAD LOW MVFR.
WINDS WILL BE AN ISSUE TODAY AND THEIR BLOWING OF THE SNOW COULD
SERVE TO DECREASE VISIBILITIES AS WELL. GUSTS IN THE TEENS COULD
START WITHIN THE NEXT COUPLE OF HOURS AND WILL ONLY SEE SUSTAINED
SPEEDS AND GUSTS INCREASE THROUGHOUT THE DAY WITH GUSTS AROUND 30
KTS BY 0Z AND LASTING THROUGHOUT THE OVERNIGHT. WINDS WILL MAINLY BE
WESTERLY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...CP/JAS/MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
210 PM EST THU JAN 12 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW
&&
.SYNOPSIS...A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL
INDIANA...USHERING AN ARCTIC AIRMASS INTO CENTRAL INDIANA FOR THE
NEXT FEW DAYS. AN UPPER LEVEL LOW PRESSURE SYSTEM WILL EXIT THE
STATE TONIGHT...HOWEVER...MOISTURE WRAPPING AROUND THE LOW WILL
LIKELY RESULT IN SCATTERED SNOW SHOWERS...PARTICULARLY THIS
EVENING.
THE STRONG LOW WILL LINGER ACROSS THE NORTHEAST UNITED STATE ON
FRIDAY...PROVIDING A COLD...ARCTIC FLOW OF AIR TO CENTRAL INDIANA.
A FEW SNOW SHOWERS CANNOT BE RULED OUT ON FRIDAY.
A QUICK MOVING RIDGE OF HIGH PRESSURE WILL PUSH ACROSS THE STATE
FRIDAY NIGHT AND SATURDAY...PROVIDING MORE COLD...CLOUDY...BUT DRY WEATHER.
ANOTHER UPPER LEVEL DISTURBANCE WILL PUSH INTO THE STATE FROM THE
NORTHWEST ON SATURDAY NIGHT AND SUNDAY...AND THIS MAY PROVIDE
ANOTHER BRIEF ROUND OF SNOW SHOWERS.
THE COLD AIR IS EXPECTED TO EXIT EARLY NEXT WORK WEEK AS THE FLOW
ALOFT BECOMES MORE WESTERLY USHERING MILD PACIFIC AIR BACK TO THE
OHIO VALLEY.
&&
.NEAR TERM /TONIGHT/...
SURFACE ANALYSIS SHOWS LOW PRESSURE OVER SOUTHERN ONTARIO EARLY
THIS AFTERNOON AND A COLD FRONT STRETCHED SOUTH ACROSS WESTERN
OHIO. MUCH COLDER AIR WAS FOUND ACROSS CENTRAL ILLINOIS AND
WESTERN CENTRAL INDIANA WHERE TEMPERATURES WERE IN THE TEENS.
WATER VAPOR IMAGERY INDICATE THE UPPER LOW OVER SE
MISSOURI...DRIVING EASTWARD. RADAR TRENDS SHOW MUCH DRIER AIR
WRAPPING IN TO THE SYSTEM FROM THE SOUTHWEST. MODELS AGREE THAT
THE UPPER SYSTEM WILL PUSH ACROSS THE STATE TONIGHT...HOWEVER BEST
FORCING IS LOST AFTER 06Z. POTENTIAL VORTICITY MUCH DRIER ARRIVING
ALONG WITH SUBSIDENCE AFTER 06Z...HOWEVER FORECAST SOUNDINGS
CONTINUE TO SUGGEST DEEP SATURATION. ALSO 850MB POTENTIAL
TEMPERATURE SURFACE SHOWS A WEAK TROWAL WORKING ACROSS THE
STATE...BUT EXITING AFTER 06Z. THUS WILL KEEP POPS GOING INTO THE
EVENING HOURS AS FORCING WILL BE FAVORABLE...HOWEVER WILL TAPER
POPS OFF AFTER 06Z AS BEST DYNAMIC SHIFT WELL TO THE NORTHEAST.
GIVEN THE DRY AIR WORKING INTO THE AREA ALONG WITH THE FORCING
ENDING BY 06Z...FEEL THAT SNOW AMOUNTS ARE MORE LIKELY TO END UP
AT THE LOWER END OF THE ADVISORY CRITERIA. AS FOR TEMPS WILL TREND
COOLER THAN MAVMOS GIVEN THE STRONG COLD AIR ADVECTION.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
MODELS REMAIN IN PRETTY GOOD OVERALL AGREEMENT DURING THIS PERIOD
AND WILL USE A BLEND.
BROAD CYCLONIC FLOW WILL REMAIN IN PLACE ON FRIDAY AS THE UPPER
LOW DEPARTS AND FORECAST SOUNDINGS INDICATE DEEP SATURATION BUT
MINIMAL FORCING THROUGH 18Z. SOUNDINGS BEGIN TO DRY OUT AFTER 18Z AS
THE COLD ARCTIC AIR MASS BEGINS TO SETTLE IN. THUS WILL CONTINUE
LOW CHANCE POPS DURING THE MORNING HOURS...BUT TAPER OFF TO A DRY
FORECAST IN THE AFTERNOON AS DRIER AIR ARRIVES. WILL TREND COLDER
THAN MAVMOS FOR HIGHS.
COLD NORTHWEST FLOW WILL PERSIST ALOFT ON FRIDAY NIGHT AND ANOTHER
WEAK DISTURBANCE WILL PUSH ACROSS THE STATE. HOWEVER MOISTURE IS
LIMITED AND NO PRECIP WILL BE EXPECTED. FURTHERMORE WITH A FRESH
SNOW COVER AND 850MB TEMPS THAT HAVE FALLEN TO NEAR -11C...WILL
TREND LOWS COLDER THAN MAVMOS.
ANOTHER STRONGER UPPER DISTURBANCE WILL PUSH INTO THE AREA ON
SATURDAY AND SATURDAY NIGHT. GFS IS MUCH DRIER THAN THE NAM. GIVEN
THE EXPECTED FORCING...FEEL THAT THE NAM HANDLES THE SITUATION
HERE AND LOW POPS APPEAR NEEDED. WITH COLD AIR IN PLACE PRECIP
TYPE WILL BE SNOW AS THIS CLIPPER MOVES THROUGH. AGAIN GIVEN THE
EXPECTED CLOUDS WILL TREND HIGHS ON SATURDAY COLDER THAN MAVMOS
AND STICK CLOSE ON LOWS.
A RIDGE OF HIGH PRESSURE WILL THEN BUILD UP ACROSS CENTRAL INDIANA
ON SUNDAY AS WARM AIR ADVECTION BEGINS AS THE DOME OF COLD AIR
BEGINS TO DEPART TO THE EAST. STRONG SOUTHERLY FLOW WILL SET UP BY
SUNDAY EVENING AS HIGH PRESSURE SETTLES ACROSS APPALACHIA AND A LOW
DEVELOPS OVER THE WESTERN PLAINS STATES. WILL AIM FOR A DRY SUNDAY
ALONG WITH TEMPS WARMER THAN MEXMOS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONGER RANGE MODEL DATA SUGGEST A PROGRESSIVE AND POTENTIALLY
ENERGETIC PATTERN ACROSS THE COUNTRY WITH JET STREAM WINDS PROGGED
IN THE 120-170KT RANGE THROUGHOUT MOST OF THE EXTENDED PERIOD.
ENSEMBLES ARE KEYING ON TWO SYSTEMS...ONE PASSING THROUGH IN THE
EARLY TO MIDDLE PARTS OF NEXT WEEK AND ANOTHER POSSIBLY AROUND
THURSDAY. AT THIS TIME...THE FIRST SYSTEM LOOKS TO BE THE STRONGER
OF THE TWO. WILL CONTINUE WITH POPS FROM MONDAY THROUGH TUESDAY
NIGHT...WITH THE HIGHEST POPS MONDAY NIGHT. JUST ABOUT ALL OF THE
ENSEMBLES TAKE THE SURFACE LOW NORTH OF THE LOCAL AREA...SO THIS
LOOKS TO BE MAINLY A RAIN EVENT...WITH SOME POTENTIAL FOR LIGHT SNOW
NEAR THE END OF THE EVENT.
SYSTEM ON THURSDAY LOOKS TO BE MORE OF A CLIPPER TYPE...AS MAIN
UPPER TROUGH AXIS IS PROGGED TO BE NEAR THE EAST COAST. WILL GO WITH
CHANCE POPS FOR LIGHT SNOW AT THAT TIME.
&&
.AVIATION /DISCUSSION FOR THE 121500Z KIND TAF UPDATE/...
RADAR TRENDS SUGGEST THE ARRIVAL OF THE SNOW AT KIND MAY BE SOONER
THAN WHAT IS CURRENTLY IN THE FORECAST. WILL NUDGE UP THE ARRIVAL OF
THE SNOW AND ASSOCIATED IFR VISIBILITY RESTRICTIONS TO AROUND
121600Z. UPSTREAM OBSERVATIONS ACROSS ILLINOIS SUGGEST POTENTIAL FOR
A PERIOD OF LIFR VISIBILITY RESTRICTIONS LATER THIS AFTERNOON. MAY
NEED TO ADD THIS IN LATER UPDATES. PREVIOUS DISCUSSION FOLLOWS.
SITES WILL START OFF LOW MVFR OR IFR DUE TO CEILINGS WITH MAINLY
MVFR VISIBILITIES. THESE CONDITIONS SHOULD CONTINUE FOR THE NEXT FEW
HOURS UNTIL SNOW SHOWERS BEGIN TO ARRIVE IN THE WEST AROUND 15Z AND
SPREAD NORTH AND EAST IMPACTING ALL THE SITES BY 18Z. USED TIMING OF
ARRIVAL FROM RUC AND HRRR...WHICH WERE AN HOUR OR SO FASTER THAN THE
VSREFS. WITH SOME ECHOES LOOKING PRETTY STRONG IN THE HRRR FOR THE
INITIAL WAVE OF SNOW THAT MOVES THROUGH DID INCLUDE A TEMPO GROUP OF
LOWER VISIBILITIES. USED THE VSREFS TO COME UP WITH 1 1/2SM FOR ALL
THE SITES FOR A COUPLE OF HOURS AFTER SNOW BEGINS. AFTER THIS
INITIAL SHOT SNOW WILL BE MORE SHOWERY AND ON AND OFF IN NATURE AND
THINK IFR CEILINGS WITH MVFR VISIBILITIES SHOULD COVER THIS WELL.
LATER TONIGHT AROUND 0Z COULD SEE ANOTHER BOUT OF HEAVIER SNOW
SHOWERS AGAIN WITH WIDESPREAD VISIBILITIES AROUND A MILE AND A
HALF...BUT THESE CONDITIONS SHOULD IMPROVE SOMEWHAT AFTER 6Z TO MORE
WIDESPREAD LOW MVFR.
WINDS WILL BE AN ISSUE TODAY AND THEIR BLOWING OF THE SNOW COULD
SERVE TO DECREASE VISIBILITIES AS WELL. GUSTS IN THE TEENS COULD
START WITHIN THE NEXT COUPLE OF HOURS AND WILL ONLY SEE SUSTAINED
SPEEDS AND GUSTS INCREASE THROUGHOUT THE DAY WITH GUSTS AROUND 30
KTS BY 0Z AND LASTING THROUGHOUT THE OVERNIGHT. WINDS WILL MAINLY BE
WESTERLY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...CP/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1134 AM EST THU JAN 12 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS INDIANA THIS MORNING. THEN A
STRONG UPPER LOW WILL MOVE ACROSS SOUTHERN INDIANA THIS EVENING AND
TO THE EASTERN GREAT LAKES FRIDAY. AN UPPER LEVEL DISTURBANCE WILL
TRACK ACROSS THE MID MISSISSIPPI AND OHIO VALLEYS LATE SATURDAY.
IN THE EXTENDED THE UPPER FLOW BECOMES MORE ZONAL EARLY NEXT WEEK
CAUSING TEMPERATURES TO MODERATE. AN UPPER DISTURBANCE WILL AFFECT
OUR WEATHER BY LATE MONDAY AND A COLD FRONT WILL MOVE ACROSS OUR
REGION TUESDAY. HIGH PRESSURE BEHIND THIS FRONT WILL BUILD ACROSS
OUR REGION BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THIS AFTERNOON/...
RADAR TRENDS INDICATE SNOW SHOWERS PUSHING ACROSS THE FORECAST
AREA AHEAD OF THE ARCTIC FRONT. VERY COLD AIR...IN THE TEENS...WAS
FOUND BEHIND THE FRONT AND IS EXPECTED TO ADVECT ACROSS THE
FORECAST AREA THIS AFTERNOON. HAVE TRENDED HOURLY TEMPERATURE
GRIDS MUCH LOWER THIS AFTERNOON REFLECTING THIS CHANGE. ALSO HAVE
RAISED POPS TO CATEGORICAL BASED UPON RECENT RADAR TRENDS.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MODELS ARE INDICATING THAT BEST TIME FRAME FOR SNOW ACCUMULATION
WILL BE FRI 00-06Z TONIGHT. BEST QVECTOR CONVERGENCE AND
FRONTOGENETIC BANDING WILL BE ACROSS THE NORTHERN COUNTIES OF
FORECAST AREA. TOTAL ACCUMULATIONS BY FRIDAY MORNING WILL RANGE FROM
1 TO 2 INCHES SOUTHERN SECTIONS...2 TO 3 INCHES ALONG THE INTERSTATE
70 CORRIDOR TO AROUND 3 TO 5 INCHES NEAR KOKOMO.
ISENTROPIC LIFT WILL ALSO BE BEST OVER THE NORTHERN COUNTIES...WITH
MOISTURE LACKING OVER THE SOUTHERN COUNTIES. SATURATION IN THE
DENDRITIC GROWTH ZONE WAS NOT OVERLY IMPRESSIVE EITHER...WHICH WILL
LIMIT SNOWFALL.
WRAPAROUND MOISTURE WILL RESULT IN SNOW SHOWERS ACROSS THE
NORTHEAST QUADRANT THROUGH FRIDAY MORNING. HOWEVER...THE MAIN
THREAT ON FRIDAY WILL BE THE STRONG WEST WINDS WITH SUSTAINED
SPEEDS OF 15 TO 25 MPH AND GUSTS TO 30 MPH. THIS WILL CREATE
BLOWING AND DRIFTING SNOW AND REDUCED VISIBILITIES. AS A
RESULT...CARRIED THE WINTER WEATHER ADVISORY TO FRI 18Z.
COLD ARCTIC AIR WILL SIT ACROSS CENTRAL INDIANA IN WAKE OF THIS
SYSTEM INTO THE WEEKEND. MODELS HAVE TRENDED A LITTLE COLDER FRIDAY
THROUGH SATURDAY AND WITH A COUPLE OF INCHES OF SNOW COVER...SEE NO
REASON NOT TO FOLLOW THIS TREND.
WEAK AREA OF HIGH PRESSURE WILL MOVE ACROSS OUR REGION LATE FRIDAY
NIGHT AND EARLY SATURDAY. THEN MODELS BRING A FAST MOVING CLIPPER
INTO THE OHIO VALLEY BY LATE SATURDAY. WESTERN AND SOUTH CENTRAL
SECTIONS COULD SEE UP TO AN INCH BY SATURDAY EVENING BEFORE THIS
SYSTEM MOVES OFF QUICKLY TO THE EAST SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
UPPER RIDGING BUILDS IN AND MOVES ACROSS THE AREA SUNDAY AND SUNDAY
NIGHT BRINGING IN SOME DRY AIR AND SCATTERING OUT SKY COVER. DURING
THE DAY MONDAY THE AREA WILL BE ON THE BACK SIDE OF THE RIDGE WITH
AN UPPER TROUGH TO THE EAST AND A COLD FRONT FIRMING UP OVER THE
PLAINS. THIS WILL ALLOW WARM ADVECTION TO RAMP UP AND ISENTROPIC
LIFT TO ENTER THE AREA BRINGING SMALL CHANCES FOR RAIN ON MONDAY. BY
MONDAY NIGHT THE LIFT REALLY INCREASES AHEAD OF THE COLD FRONT AND
MOISTURE SHOULD BE STREAMING UP FROM THE GULF ON A 50+ KT LOW LEVEL
JET. THOUGHT THE LIKELY POPS FROM THE ALLBLEND MATCHED UP WITH THIS
WELL. GFS AND ECMWF HAVE A BIT OF A DIFFERENCE IN THE TIMING OF THE
COLD FRONTAL PASSAGE TUESDAY WHICH COULD MAKE A DIFFERENCE IN HIGH
TEMPERATURES FOR THE DAY AS WELL AS HOW LONG PRECIPITATION CHANCES
WILL LAST AND WHETHER THEY WILL BE IN THE FORM OF RAIN OR SNOW. WITH
THE MORE ZONAL PATTERN FAVORING THE FASTER GFS BUT RECENT
VERIFICATION FAVORING THE ECMWF WILL USE THE ALLBLEND AVERAGE FOR
CHANCE POPS ACROSS THE AREA AND GO WITH RAIN AND SNOW UNTIL BETTER
AGREEMENT EMERGES. TUESDAY NIGHT LOOKS DRY. MODELS SHOW THE NEXT
SYSTEM ARRIVING IN THE WEDNESDAY NIGHT TO THURSDAY NIGHT TIME
SPAN BRINGING ANOTHER QUICK SHOT OF COLD AIR AND POSSIBLE PRECIP
CHANCES...BUT THOSE ARRIVE AFTER THE FORECAST PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 121500Z KIND TAF UPDATE/...
RADAR TRENDS SUGGEST THE ARRIVAL OF THE SNOW AT KIND MAY BE SOONER
THAN WHAT IS CURRENTLY IN THE FORECAST. WILL NUDGE UP THE ARRIVAL OF
THE SNOW AND ASSOCIATED IFR VISIBILITY RESTRICTIONS TO AROUND
121600Z. UPSTREAM OBSERVATIONS ACROSS ILLINOIS SUGGEST POTENTIAL FOR
A PERIOD OF LIFR VISIBILITY RESTRICTIONS LATER THIS AFTERNOON. MAY
NEED TO ADD THIS IN LATER UPDATES. PREVIOUS DISCUSSION FOLLOWS.
SITES WILL START OFF LOW MVFR OR IFR DUE TO CEILINGS WITH MAINLY
MVFR VISIBILITIES. THESE CONDITIONS SHOULD CONTINUE FOR THE NEXT FEW
HOURS UNTIL SNOW SHOWERS BEGIN TO ARRIVE IN THE WEST AROUND 15Z AND
SPREAD NORTH AND EAST IMPACTING ALL THE SITES BY 18Z. USED TIMING OF
ARRIVAL FROM RUC AND HRRR...WHICH WERE AN HOUR OR SO FASTER THAN THE
VSREFS. WITH SOME ECHOES LOOKING PRETTY STRONG IN THE HRRR FOR THE
INITIAL WAVE OF SNOW THAT MOVES THROUGH DID INCLUDE A TEMPO GROUP OF
LOWER VISIBILITIES. USED THE VSREFS TO COME UP WITH 1 1/2SM FOR ALL
THE SITES FOR A COUPLE OF HOURS AFTER SNOW BEGINS. AFTER THIS
INITIAL SHOT SNOW WILL BE MORE SHOWERY AND ON AND OFF IN NATURE AND
THINK IFR CEILINGS WITH MVFR VISIBILITIES SHOULD COVER THIS WELL.
LATER TONIGHT AROUND 0Z COULD SEE ANOTHER BOUT OF HEAVIER SNOW
SHOWERS AGAIN WITH WIDESPREAD VISIBILITIES AROUND A MILE AND A
HALF...BUT THESE CONDITIONS SHOULD IMPROVE SOMEWHAT AFTER 6Z TO MORE
WIDESPREAD LOW MVFR.
WINDS WILL BE AN ISSUE TODAY AND THEIR BLOWING OF THE SNOW COULD
SERVE TO DECREASE VISIBILITIES AS WELL. GUSTS IN THE TEENS COULD
START WITHIN THE NEXT COUPLE OF HOURS AND WILL ONLY SEE SUSTAINED
SPEEDS AND GUSTS INCREASE THROUGHOUT THE DAY WITH GUSTS AROUND 30
KTS BY 0Z AND LASTING THROUGHOUT THE OVERNIGHT. WINDS WILL MAINLY BE
WESTERLY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...JH
NEAR TERM...PUMA
SHORT TERM...JH
LONG TERM....CP
AVIATION...CP/JAS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
339 PM CST THU JAN 12 2012
.SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB LOW ALONG THE IA/WI BORDER WITH
ANOTHER IN SOUTHEAST LOWER MICHIGAN. A TROF EXTENDED SOUTH FROM
THE IA/WI LOW INTO SOUTHEAST MISSOURI. RADAR TRENDS THROUGH EARLY
AFTERNOON SHOW AN UPPER LEVEL FEATURE THAT IS PIVOTING A
DEFORMATION ZONE ACROSS EASTERN IOWA AND NORTHERN ILLINOIS.
18Z SFC ANALYSIS HAS AN OCCLUDED LOW BETWEEN KGRR AND KAZO AND
ANOTHER ON THE SOUTHERN EDGE OF LAKE HURON. THE POLAR FRONT
EXTENDED SOUTH FROM THE OCCLUDED LOW INTO CENTRAL ALABAMA. SEVERAL
WEAK TROFS RAN FROM SOUTHERN LAKE MICHIGAN INTO MISSOURI BACK UP
INTO SOUTHERN WISCONSIN AND IOWA. DEW POINTS WERE IN THE TEENS AND
20S FROM THE WESTERN GREAT LAKES AND LOWER MISSISSIPPI VALLEY TO
THE SINGLE DIGITS ABOVE AND BELOW ZERO ACROSS THE PLAINS.
&&
.SHORT TERM...TONIGHT...
RADAR AND WATER VAPOR ARE QUITE INTERESTING. A VORT MAX IS
ROTATING AROUND THE UPPER LOW IN SOUTHERN ILLINOIS WHICH IS
HELPING TO PIVOT THE DEFORMATION ZONE ACROSS THE CWFA. THE END
POINT OF THE PIVOT IS SLOWLY DRIFTING TO THE EAST SOUTHEAST AS THE
UPPER LOW MOVES INTO THE OHIO VALLEY PER RUC TRENDS. THUS LIGHT TO
MODERATE SNOW WITH BURSTS OF HEAVY SNOW WILL CONTINUE THROUGH 6 PM.
THE RUC SHOWS ANOTHER VORT MAX ROTATING FROM NORTHEAST ILLINOIS
BACK INTO EASTERN IOWA DURING THE EARLY EVENING. THIS FEATURE
SHOULD ALLOW THE SNOW TO MAINTAIN ITSELF THROUGH 9 PM. AFTER 9 PM
THE FORCING OVER THE WESTERN THIRD OF THE CWFA WEAKENS RAPIDLY SO
THE SNOW THERE SHOULD QUICKLY TAPER TO FLURRIES.
THE RUC TRENDS BLEND IN NICELY WITH THE WRF/GFS TRENDS INDICATING
THE OVERALL FORCING WEAKENING RAPIDLY AFTER MIDNIGHT ACROSS THE
EASTERN TWO THIRDS OF THE CWFA. THUS SNOW WILL TAPER TO FLURRIES
ACROSS THE REMAINDER OF THE CWFA AFTER MIDNIGHT WITH ALL BUT THE
FAR EASTERN PARTS OF THE CWFA SEEING THE FLURRIES END PRIOR TO
SUNRISE.
THE CURRENT HEADLINES WILL REMAIN AS IS FOR NOW. IF THE TRENDS
FROM THE RUC AND OTHER MODELS ARE CORRECT...THE POSSIBILITY DOES
EXIST THAT THE HEADLINES MAY BE CANCELLED EARLIER THAN THE CURRENT
END TIMES.
NOW FOR AMOUNTS. ADDITIONAL SNOWFALL THIS EVENING SHOULD RANGE
FROM A DUSTING IN THE FAR WESTERN PARTS OF THE CWFA TO JUST OVER
AN INCH IN THE EASTERN THIRD OF THE CWFA. MOST OF THIS ADDITIONAL
SNOWFALL WILL OCCUR BETWEEN 6 AND 8 PM. AFTER MIDNIGHT...AN
ADDITIONAL DUSTING MAY OCCUR IN THE EASTERN THIRD OF THE CWFA
WHERE LIGHT SNOW WILL LINGER THE LONGEST.
SO...STORM TOTALS SHOULD BE A GENERAL 3 TO 6 INCHES ACROSS THE
AREA. AN AREA 20 MILES EITHER SIDE OF A LINE CENTERED FROM CEDAR
RAPIDS TO ROUGHLY STERLING SHOULD SEE 5 TO 7 INCHES WITH LOCALLY
HIGHER AMOUNTS.
..08..
.LONG TERM...FRIDAY THROUGH NEXT THURSDAY...
ACTIVE PATTERN TO PREVAIL THROUGH THE PERIOD.
FRI-FRI NGT...ADDITIONAL ENERGY DIVING DOWN BACKSIDE OF DEPARTING
SYSTEM WILL KEEP CLOUDS AND POSSIBLY FEW FLURRIES AROUND
FOR A TIME FRI AM. THEN EXPECT SOME DECREASE IN CLOUDS FRI AFTN
WITH SUBSIDENCE. BRISK NW WINDS CONTINUE AND WITH CLOUDS SLOW TO
DECREASE AND FRESH SNOW HAVE SIDED AT OR BELOW COLD SIDE OF GUIDANCE
FOR HIGHS. NEXT CLIPPER SYSTEM WHICH SEEN ON WATER VAPOR JUST
COMING INTO BC APPEARS TO BE A LITTLE STRONGER THAT PROGGED. THIS
ENERGY TO HEAD SE FRI NGT AND WILL SEE INCREASE IN CLOUDS WITH WARM
ADVECTION WING WITH CHC OF -SN/--SN LATE PORTIONS OF W/NW. LIGHT
WINDS AND PARTIAL CLEARING FOR TIME FRI EVE SHOULD AID IN QUICK DROP
TO NEAR OR BELOW GUIDANCE MINS BEFORE TEMPS STEADY OR RISE WITH
CLOUDS AND LLVL WARM ADVECTION OVRNGT.
SAT-SAT NGT...CLIPPER SYSTEM TO PASS DURING DAY WITH STILL PLENTY
OF SPREAD ON TRACK AND STRENGTH. ENHANCED BAROCLINICITY FROM
EVOLVING SNOW FIELD MAY PLAY ROLE... AND GIVEN THIS AND WHAT LOOKS
LIKE STRONGER WAVE WONDER IF TRACK AND POPS MAY NEED TO BE
ADJUSTED SWWD. LIMITED MOISTURE AND SO COULD END UP MOSTLY FLURRIES
WITH AREAS OF -SN WITH ANY ACCUMS MINOR AT OR BELOW 1 INCH. AT LEAST
PARTIAL CLEARING SAT NGT IN WAKE WITH LIGHT WINDS AND HAVE LOWERED
MINS TO BELOW GUIDANCE... BUT RETURN FLOW KICKS IN LATE THAT MAY SEE
TEMPS CLIMB OVRNGT.
SUN-SUN NGT... DRY WITH MODERATING TEMPS AS WARM ADVECTION STRENGTHENS
ON GUSTY SLY WINDS... WITH HEIGHTS BUILDING ALOFT. FRONT MOVES INTO
IA SUN NGT BUT SUGGESTION OF PCPN STAYING SOUTH OF CWA ACROSS PORTIONS
OF MO SWD WITHIN DEEPER LLVL MOISTURE RETURN.
MON-TUE... NEXT FRONT TO PASS WITH ENERGY AND BAROCLINICITY FAVORING
SFC LOW DEVELOPMENT ALONG FRONT PASSING NEAR REGION THAT MAY
REQUIRE POPS BEING RAISED. THERMAL PARAMETERS SUPPORT MAINLY RAIN MON
BUT AS FRONT SAGS ACROSS CWA MON NGT AND COLDER AIR MOVES IN COULD
SEE MIX THEN CHANGE TO SNOW WITH ANY RESIDUAL MOISTURE ON BACKSIDE
LINGERING INTO TUE. ANY SNOW ACCUMS WOULD APPEAR TO BE LIGHT ATTIM.
WED-THU...MUCH COLDER WITH CHC OF SNOW LATE PD WITH NEXT BOUT OF ENERGY.
..05..
&&
.AVIATION...
IFR TO LIFR CONDITIONS WITH SNOW WILL CONTINUE THROUGH 02Z/13. AFT
02Z/13 CONDITIONS WILL SLOWLY IMPROVE TO MVFR. SNOW INTENSITY WILL
DECREASE RAPIDLY AFT 02Z/13 AND TAPER TO FLURRIES BEFORE ENDING.
VSBYS TO BECOME VFR AFT 06Z/13 WITH MVFR CIGS.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER STORM WARNING UNTIL 3 AM CST FRIDAY FOR CLINTON-JACKSON-
SCOTT.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BENTON-
BUCHANAN-DES MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-
LEE-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR CEDAR-
DELAWARE-DUBUQUE-JONES-LINN.
IL...WINTER STORM WARNING UNTIL 3 AM CST FRIDAY FOR CARROLL-JO
DAVIESS-ROCK ISLAND-STEPHENSON-WHITESIDE.
WINTER WEATHER ADVISORY UNTIL 3 AM CST FRIDAY FOR BUREAU-HANCOCK-
HENDERSON-HENRY IL-MCDONOUGH-MERCER-PUTNAM-WARREN.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1147 AM CST THU JAN 12 2012
.UPDATE...
BASED ON MORNING UA AND CURRENT TRENDS FROM THE RUC AND RADAR...A
PORTION OF THE WINTER WEATHER ADVISORY HAS BEEN UPGRADED TO A
WINTER STORM WARNING. WE WILL EASILY ACHIEVE A VERY HIGH END
ADVISORY. HOWEVER...THE LACK OF SNOW SO FAR THIS SEASON COMBINED
WITH THE WIND HAS RESULTED IN A LOWERING OF THE NORMAL THRESHOLDS.
RUC TRENDS SHOW THE DEFORMATION ZONE SETTING UP OVER ROUGHLY THE
NORTHERN CWFA AND WILL PIVOT TO THE NORTHEAST DURING THE AFTERNOON
HOURS. THE WAA TOOL SUGGESTS THE STRONGEST FORCING ON THE WESTERN
EDGE OF THE NEW WARNING AREA WILL MOVE EAST DURING THE AFTERNOON
TOWARD THE MISSISSIPPI RIVER.
SNOWFALL AMOUNTS HAVE BEEN RAISED BASED ON REPORTS SO FAR AND
RUC/RADAR TRENDS.
THE WINDS SO FAR HAVE NOT GOTTEN AS STRONG AS EXPECTED. MANY AREAS
ARE ONLY 15 TO 25 MPH BUT MORE SITES ARE STARTING TO INCREASE TO
20 TO 30 MPH. GUSTS HAVE GENERALLY BEEN 30 MPH OR LESS SHOULD
INCREASE TO 35 MPH DURING THE AFTERNOON HOURS.
BASED ON RUC TRENDS...THE SNOW SHOULD RAPIDLY START SHUTTING DOWN
AROUND MID EVENING WITH LINGERING FLURRIES AFTER MIDNIGHT. AS
SUCH...THE EXPIRATION OF THE HEADLINES IN THE EASTERN CWFA HAVE
BEEN PULLED BACK TO 3 AM.
..08..
&&
.AVIATION...
SNOW WITH AREAS OF BLOWING SNOW AND IFR TO LIFR CONDITIONS EXPECTED
TO CONTINUE THROUGH THE AFTN. SNOW WILL TAPER TO FLURRIES THEN END
FROM NW TO SE THIS EVE WITH MVFR CIGS PREVAILING FOR MUCH OF THE
REST OF PD. WINDS GENERALLY NW AT 10-20 KTS WITH HIGHER GUSTS AT TIMES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER STORM WARNING UNTIL 3 AM CST FRIDAY FOR CLINTON-JACKSON-
SCOTT.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BENTON-
BUCHANAN-DES MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-
LEE-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR CEDAR-
DELAWARE-DUBUQUE-JONES-LINN.
IL...WINTER STORM WARNING UNTIL 3 AM CST FRIDAY FOR CARROLL-JO
DAVIESS-ROCK ISLAND-STEPHENSON-WHITESIDE.
WINTER WEATHER ADVISORY UNTIL 3 AM CST FRIDAY FOR BUREAU-HANCOCK-
HENDERSON-HENRY IL-MCDONOUGH-MERCER-PUTNAM-WARREN.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1243 PM EST THU JAN 12 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE SOUTH TODAY AND WILL MOVE INTO
THE GULF OF MAINE BY THIS EVENING. LOW PRESSURE WILL WEAKEN AS IT
MOVES INTO THE MARITIMES TONIGHT. AT THE SAME TIME...ANOTHER AREA
OF LOW PRESSURE WILL APPROACH NEW ENGLAND FROM THE WEST. LOW
PRESSURE WILL MOVE NORTHEAST THROUGH NORTHERN NEW ENGLAND ON
FRIDAY SWINGING A TRAILING COLD FRONT THROUGH THE AREA AND SETTING
UP A STRONG SOUTHWEST FLOW IN IT`S WAKE. A TROUGH OF LOW PRESSURE
WILL LINGER OF THE AREA FRIDAY NIGHT AND WILL MOVE OFFSHORE ON
SATURDAY. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST
SATURDAY NIGHT THROUGH SUNDAY. HIGH PRESSURE WILL CREST OVER THE
REGION ON MONDAY AND SHIFT OFFSHORE IN THE AFTERNOON. A COLD FRONT
WILL APPROACH FROM THE NORTHWEST MONDAY NIGHT THROUGH TUESDAY. LOW
PRESSURE WILL DEVELOP ALONG THE FRONT AND WILL MOVE INTO NORTHERN
NEW ENGLAND BY WEDNESDAY MORNING SWINGING THE FRONT THROUGH THE
REGION. LOW PRESSURE WILL RACE OFF TO THE NORTHEAST ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1742Z UPDATE...
HAVE ADDED A SMALL AREAS...COASTAL CUMBERLAND...LINCOLN AND SAGAHOC
COUNTIES TO THE WARNING BASED ON CURRENT CONDS AND OBS. VERY
LITTLE CHANGE TO THE SNOWFALL FORECAST...GOING FROM 3-6 INCHES TO
4-8 INCHES.
RADAR SHOWING A GOOD BATCH OF +SN TO CROSS THAT
REGION OVER THE NEXT HOUR OR TWO...DELIVERING 1" PER HOUR SNOWFALL
RATES BEFORE THE PCPN TAPERS OFF. ANOTHER NICE BATCH OF HEAVY PCPN
IS ROTATING NORTH FROM MASS AT THIS HOUR AS WELL.
UPDATE...
UPDATE WAS TO ADD WINTER STORM WARNINGS FOR SOUTH-CENTRAL NH PER
LATEST OBS/REPORTS OF SNOWFALL IN THAT AREA. WRN NH WILL BE
GETTING SHADDOWED SHORTLY...OTRW THEY WOULD HAVE BEEN INCLUDED AS
WELL.
TEMPS NOW WARMING ALONG THE COAST. CONSIDERED WARNINGS FOR PWM
NORTH...HOWEVER...READINGS NOW IN THE UPPER 20S/LOWER 30S AND
CLIMBING. A MIX IS NOW OCCURRING IN YORK COUNTY...AND IN THE
MIDCOAST REGION. WOULDN`T BE SURPRIZED HOWEVER IF A FEW LOCATIONS
BETWEEN PWM AND IWI RECEIVE LOCALLY 7" SNOWFALL.
PREV DISC..
COASTAL FRONT IN FULL SWING ALONG THE COAST WITH TEMPERATURES
FALLING QUICKLY ALONG THE SHORELINE. PORTLAND NOW DOWN TO 25
DEGREES...JUST WEST OF THE COASTAL FRONT (HAVE LOWERED MAX TEMP
FCST AND DEW POINT VALUES FOR TODAY). THIS COLD/DRY AIR WILL
CONTINUE TO FUNNEL DOWN THE COAST...AND WE HAVE ALREADY BEGUN TO
ADJUST SNOWFALL TOTALS UPWARDS ALONG PORTIONS OF THE COAST.
BEST PRESSURE FALLS WITH THE SURFACE LOW NOW SOUTH OF LONG ISLAND.
BELIEVE MODELS ARE OVERDOING THE WARM AIR...BOTH AT THE SURFACE
AND ALOFT. COASTAL ROCKINGHAM COUNTY AND SOUTHERNMOST PORTIONS OF
YORK COUNTY HOWEVER STILL REMAIN RELATIVELY VULVERNABLE TO THE MIX
OR CHANGEOVER TO RAIN. HOWEVER...WE ARE DELAYING THIS ONSET OF
MIXED PCPN BY A COUPLE HOURS THIS MORNING.
TIDES ARE STARTING TO RUN PRETTY HIGH ALONG THE COAST...WITH
BUILDING WAVES ALONG WITH DEVELOPING GALE FORCE WINDS. EXPECT
SPLASH-OVER NEAR THE TIME OF HIGH TIDE AND WILL ADD THIS TO
STATEMENTS AND/OR THE HWO SHORTLY.
WARNINGS/ADVISORIES...ALL LOOKS GOOD AT THE MOMENT. AM MONITORING
PORTIONS OF SOUTH-CENTRAL HAMPSHIRE AND THE MAINE COASTLINE FOR
POSSIBLE UPGRADES TO ADDITIONAL WARNINGS. WILL TAKE A QUICK LOOK
AT THE NEW NAM - WITH ONLY MODEST INTEREST AS IT HAS BEEN WAY TOO
WARM...BUT STRONG ON THE QPF FOR SW ME AND SE NH PROVIDING 1+" QPF
AS OF THE 06Z RUN. THIS AFTER RUNNING RELATIVELY DRY AT 00Z. MORE
IMPORTANTLY...WE`RE TAKING A GOOD LOOK AT THE LATEST HRRR MODEL
RUN. THIS MODEL BRINGS THE LOW OFF THE COAST OF MAINE LATER THIS
AFTERNOON AND BACKS WINDS WITH TIME...KEEPING WARM SURFACE AIR
OFFSHORE. HAVING MENTIONED SHORT RANGE GUIDANCE...WEIGHTING OF
THIS FORECAST IS HIGHLY DEPENDENT ON THE POSITIONING AND
ENHANCEMENT OF OUR FULLY DEVELOPED COASTAL FRONT.
PREV DISC...
LOW PRESSURE MOVING UP FROM THE SOUTH WILL BRING A VARIETY OF
PRECIPITATION TO THE REGION TODAY. EXPECT SNOW TO MOVE INTO
SOUTHERN NEW HAMPSHIRE AND SOUTHWEST MAINE THROUGH DAYBREAK. TEMPS
ALREADY IN THE MID 30S IN COASTAL AREAS SO EXPECT PRECIPITATION TO
GO OVER TO RAIN FAIRLY QUICKLY THIS MORNING IN SOUTHEAST NEW
HAMPSHIRE AND ADJACENT SOUTHWEST COASTAL MAINE. EVAPORATIONAL
COOLING AT THE ONSET MAY LAST LONG ENOUGH TO PRODUCE AN INCH OR
TWO OF SNOW IN THESE AREAS BEFORE CHANGEOVER.
FARTHER TO THE NORTH IN SOUTH CENTRAL NEW HAMPSHIRE EXPECT MORE IN
THE WAY OF SNOW BEFORE MIXING TAKES PLACE WITH 3 TO 6 INCHES
LIKELY THROUGH EARLY AFTERNOON. LOOKING FOR PRECIPITATION TO
REMAIN IN THE FORM OF SNOW FOR MUCH OF THE DAY IN NORTHERN NEW
HAMPSHIRE AND INTERIOR SECTIONS OF MAINE WHICH COULD SEE AS MUCH
AS 6 TO 10 INCHES BEFORE PRECIPITATION WINDS DOWN AS A PERIOD OF
SLEET OR LIGHT FREEZING RAIN LATE THIS AFTERNOON AND THIS EVENING.
WILL BE STICKING WITH CURRENT ADVISORIES AND WARNINGS WITH NO
CHANGES PLANNED. EXPECT HIGHS IN THE MID 30S TO NEAR 40 IN COASTAL
AREAS BUT COLD AIR WILL HANG TOUGH IN INTERIOR SECTIONS WHERE
HIGHS WILL ONLY REACH THE MID 20S TO LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
A LULL IN THE ACTION DURING THE FIRST HALF OF TONIGHT AS LOW
PRESSURE WEAKENS AND LIFTS NORTHEAST INTO THE MARITIMES. MAY SEE
SOME LIGHT PATCHY FREEZING DRIZZLE OR MIXED PRECIPITATION DURING
THE FIRST HALF OF THE NIGHT BUT ANY ACCUMULATIONS WILL BE MINOR.
LOW PRESSURE APPROACHING FROM THE GREAT LAKES WILL SWING AN
OCCLUSION NORTHEAST TOWARD NEW ENGLAND AFTER MIDNIGHT WHICH WILL
BRING ANOTHER ROUND OF MIXED PRECIPITATION INTO SOUTHWEST ZONES BY
DAYBREAK SO SOME FORM OF ADVISORIES MAY BE NEEDED FOR LATE TONIGHT
INTO FRIDAY.
EXPECT ACTIVITY ALONG THE BOUNDARY TO QUICKLY LIFT NORTHEAST
THROUGH THE REMAINDER OF THE FORECAST AREA DURING THE MORNING
HOURS...PERSISTING IN THE MOUNTAINS WELL INTO THE AFTERNOON WITH
MIXED PRECIPITATION CHANGING BACK TO SNOW AS COLDER AIR SHIFTS
BACK INTO THE REGION. COULD SEE SEVERAL INCHES OF ACCUMULATION
LATE IN THE DAY AS UPSLOPE FLOW KICKS IN BEHIND DEPARTING LOW.
ELSEWHERE RAIN AND MIXED PRECIPITATION WILL TAPPER TO SNOW SHOWERS
IN THE AFTERNOON.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A STRONG ARCTIC CD FNT MOVES THRU FRIDAY NGT BRINGING IN CD
CANADIAN AIR ON GUSTY W THEN NW WINDS. SHSN PSBL...THOUGH MOSTLY
CONFINED TO THE N/MT ZONES WHERE SOME ACCUMULATION PSBL. ELSEWHERE
DOWNSLOPE WINDS HELP TO MINIMIZE THE CHC OF ANY SHSN AND ALSO
DECREASES AMOUNT OF SKY COVER VERSUS THE N/MT ZONES. CD WX
DOMINATES THRU THE WEEKEND AS THE NW WIND FIELD SLOWLY EASES UP
WITH HIGH PRES APPROACHING FROM THE W. THE HIGH SETTLES OVER THE E
COAST MONDAY WITH FAIR BUT CONTINUED CD WX. THE HIGH MOVES OFF
SHORE TUESDAY ALLOWING SW FLOW TO BRING IN WARMER AIR. AN
APPROACHING CD FNT BRINGS A CHC OF -SHSN OR -SHRA TUESDAY AND
TUESDAY NGT. THE STRONG ARCTIC FNT MOVES BY FOR WEDNESDAY BRINGING
IN MORE VERY CD AND BLUSTERY WX.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR FRIDAY
NGT AND SATURDAY. USED GMOS FOR REST OF THE LONG TERM FCST... EXCEPT
USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND MIN TEMPS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...IFR/LIFR CEILINGS/VSBY DEVELOPING TODAY AND
PERSISTING THROUGH FRIDAY MORNING...IMPROVING IN THE AFTERNOON.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...STRONG ARCTIC CD FNT
MOVES THRU FRIDAY NGT WITH SHSN PSBL ALONG WITH MVFR TO IFR
CIG/VSBY...THOUGH MOST ACTIVITY CONFINED TO THE N/MT AREAS.
STRONG GUSTY W THEN NW WINDS FRIDAY NGT.
&&
.MARINE...
SHORT TERM...GALE WARNING EXTENDED THROUGH FRIDAY NIGHT.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...WILL EXTEND THE GLW
THRU FRIDAY NGT WITH EVEN A FEW PEAK GUSTS OF STORM FORCE PSBL AS
STRONG W FLOW SETS UP BEHIND DEPARTING STRONG CD FNT AND TIGHT
PRES GRADIENT SETS UP AND IS ENHANCED BY STRONG CD AIR ADVECTION
OVER THE WARMER WATERS. WINDS SLOWLY LET UP AND SEAS SLOWLY
SUBSIDE AS HIGH PRES BUILDS IN FROM THE W OVER THE WEEKEND AND
SETTLES OVER THE E COAST ON MONDAY.
&&
.TIDES/COASTAL FLOODING...
THE ASTRONOMICAL HIGH TIDE IN PORTLAND IS 10.3 FT ANEAR 1 PM THIS
AFTERNOON. A STORM SURGE OF 1 TO 1.5 FT IS EXPECTED TDA. THIS
WOULD PUSH THE TIDE TO AROUND 11.5 FT AND POSSIBLY CLOSE TO THE 12
FOOT TIDAL FLOOD STAGE. AT THIS TIME THE TIDE IS EXPECTED TO STAY
BELOW 12 FT. HOWEVER, BUILDING SEAS FROM ONSHORE WINDS WILL LIKELY
CREATE UP TO MODERATE SPLASHOVER AND BEACH EROSION AROUND THE TIME OF HIGH
TIDE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR
MEZ007>009-012>014-018>022-024>026.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MEZ023-027-028.
COASTAL FLOOD ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MEZ023-024.
NH...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR
NHZ001>006-009-010.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NHZ007-008-013-014.
COASTAL FLOOD ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NHZ014.
MARINE...GALE WARNING UNTIL 7 AM EST SATURDAY FOR ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS GRAY ME
1113 AM EST THU JAN 12 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE SOUTH TODAY AND WILL MOVE INTO
THE GULF OF MAINE BY THIS EVENING. LOW PRESSURE WILL WEAKEN AS IT
MOVES INTO THE MARITIMES TONIGHT. AT THE SAME TIME...ANOTHER AREA
OF LOW PRESSURE WILL APPROACH NEW ENGLAND FROM THE WEST. LOW
PRESSURE WILL MOVE NORTHEAST THROUGH NORTHERN NEW ENGLAND ON
FRIDAY SWINGING A TRAILING COLD FRONT THROUGH THE AREA AND SETTING
UP A STRONG SOUTHWEST FLOW IN IT`S WAKE. A TROUGH OF LOW PRESSURE
WILL LINGER OF THE AREA FRIDAY NIGHT AND WILL MOVE OFFSHORE ON
SATURDAY. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST
SATURDAY NIGHT THROUGH SUNDAY. HIGH PRESSURE WILL CREST OVER THE
REGION ON MONDAY AND SHIFT OFFSHORE IN THE AFTERNOON. A COLD FRONT
WILL APPROACH FROM THE NORTHWEST MONDAY NIGHT THROUGH TUESDAY. LOW
PRESSURE WILL DEVELOP ALONG THE FRONT AND WILL MOVE INTO NORTHERN
NEW ENGLAND BY WEDNESDAY MORNING SWINGING THE FRONT THROUGH THE
REGION. LOW PRESSURE WILL RACE OFF TO THE NORTHEAST ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
UPDATE WAS TO ADD WINTER STORM WARNINGS FOR SOUTH-CENTRAL NH PER
LATEST OBS/REPORTS OF SNOWFALL IN THAT AREA. WRN NH WILL BE
GETTING SHADDOWED SHORTLY...OTRW THEY WOULD HAVE BEEN INCLUDED AS
WELL.
TEMPS NOW WARMING ALONG THE COAST. CONSIDERED WARNINGS FOR PWM
NORTH...HOWEVER...READINGS NOW IN THE UPPER 20S/LOWER 30S AND
CLIMBING. A MIX IS NOW OCCURRING IN YORK COUNTY...AND IN THE
MIDCOAST REGION. WOULDN`T BE SURPRIZED HOWEVER IF A FEW LOCATIONS
BETWEEN PWM AND IWI RECEIVE LOCALLY 7" SNOWFALL.
PREV DISC..
COASTAL FRONT IN FULL SWING ALONG THE COAST WITH TEMPERATURES
FALLING QUICKLY ALONG THE SHORELINE. PORTLAND NOW DOWN TO 25
DEGREES...JUST WEST OF THE COASTAL FRONT (HAVE LOWERED MAX TEMP
FCST AND DEW POINT VALUES FOR TODAY). THIS COLD/DRY AIR WILL
CONTINUE TO FUNNEL DOWN THE COAST...AND WE HAVE ALREADY BEGUN TO
ADJUST SNOWFALL TOTALS UPWARDS ALONG PORTIONS OF THE COAST.
BEST PRESSURE FALLS WITH THE SURFACE LOW NOW SOUTH OF LONG ISLAND.
BELIEVE MODELS ARE OVERDOING THE WARM AIR...BOTH AT THE SURFACE
AND ALOFT. COASTAL ROCKINGHAM COUNTY AND SOUTHERNMOST PORTIONS OF
YORK COUNTY HOWEVER STILL REMAIN RELATIVELY VULVERNABLE TO THE MIX
OR CHANGEOVER TO RAIN. HOWEVER...WE ARE DELAYING THIS ONSET OF
MIXED PCPN BY A COUPLE HOURS THIS MORNING.
TIDES ARE STARTING TO RUN PRETTY HIGH ALONG THE COAST...WITH
BUILDING WAVES ALONG WITH DEVELOPING GALE FORCE WINDS. EXPECT
SPLASH-OVER NEAR THE TIME OF HIGH TIDE AND WILL ADD THIS TO
STATEMENTS AND/OR THE HWO SHORTLY.
WARNINGS/ADVISORIES...ALL LOOKS GOOD AT THE MOMENT. AM MONITORING
PORTIONS OF SOUTH-CENTRAL HAMPSHIRE AND THE MAINE COASTLINE FOR
POSSIBLE UPGRADES TO ADDITIONAL WARNINGS. WILL TAKE A QUICK LOOK
AT THE NEW NAM - WITH ONLY MODEST INTEREST AS IT HAS BEEN WAY TOO
WARM...BUT STRONG ON THE QPF FOR SW ME AND SE NH PROVIDING 1+" QPF
AS OF THE 06Z RUN. THIS AFTER RUNNING RELATIVELY DRY AT 00Z. MORE
IMPORTANTLY...WE`RE TAKING A GOOD LOOK AT THE LATEST HRRR MODEL
RUN. THIS MODEL BRINGS THE LOW OFF THE COAST OF MAINE LATER THIS
AFTERNOON AND BACKS WINDS WITH TIME...KEEPING WARM SURFACE AIR
OFFSHORE. HAVING MENTIONED SHORT RANGE GUIDANCE...WEIGHTING OF
THIS FORECAST IS HIGHLY DEPENDENT ON THE POSITIONING AND
ENHANCEMENT OF OUR FULLY DEVELOPED COASTAL FRONT.
PREV DISC...
LOW PRESSURE MOVING UP FROM THE SOUTH WILL BRING A VARIETY OF
PRECIPITATION TO THE REGION TODAY. EXPECT SNOW TO MOVE INTO
SOUTHERN NEW HAMPSHIRE AND SOUTHWEST MAINE THROUGH DAYBREAK. TEMPS
ALREADY IN THE MID 30S IN COASTAL AREAS SO EXPECT PRECIPITATION TO
GO OVER TO RAIN FAIRLY QUICKLY THIS MORNING IN SOUTHEAST NEW
HAMPSHIRE AND ADJACENT SOUTHWEST COASTAL MAINE. EVAPORATIONAL
COOLING AT THE ONSET MAY LAST LONG ENOUGH TO PRODUCE AN INCH OR
TWO OF SNOW IN THESE AREAS BEFORE CHANGEOVER.
FARTHER TO THE NORTH IN SOUTH CENTRAL NEW HAMPSHIRE EXPECT MORE IN
THE WAY OF SNOW BEFORE MIXING TAKES PLACE WITH 3 TO 6 INCHES
LIKELY THROUGH EARLY AFTERNOON. LOOKING FOR PRECIPITATION TO
REMAIN IN THE FORM OF SNOW FOR MUCH OF THE DAY IN NORTHERN NEW
HAMPSHIRE AND INTERIOR SECTIONS OF MAINE WHICH COULD SEE AS MUCH
AS 6 TO 10 INCHES BEFORE PRECIPITATION WINDS DOWN AS A PERIOD OF
SLEET OR LIGHT FREEZING RAIN LATE THIS AFTERNOON AND THIS EVENING.
WILL BE STICKING WITH CURRENT ADVISORIES AND WARNINGS WITH NO
CHANGES PLANNED. EXPECT HIGHS IN THE MID 30S TO NEAR 40 IN COASTAL
AREAS BUT COLD AIR WILL HANG TOUGH IN INTERIOR SECTIONS WHERE
HIGHS WILL ONLY REACH THE MID 20S TO LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
A LULL IN THE ACTION DURING THE FIRST HALF OF TONIGHT AS LOW
PRESSURE WEAKENS AND LIFTS NORTHEAST INTO THE MARITIMES. MAY SEE
SOME LIGHT PATCHY FREEZING DRIZZLE OR MIXED PRECIPITATION DURING
THE FIRST HALF OF THE NIGHT BUT ANY ACCUMULATIONS WILL BE MINOR.
LOW PRESSURE APPROACHING FROM THE GREAT LAKES WILL SWING AN
OCCLUSION NORTHEAST TOWARD NEW ENGLAND AFTER MIDNIGHT WHICH WILL
BRING ANOTHER ROUND OF MIXED PRECIPITATION INTO SOUTHWEST ZONES BY
DAYBREAK SO SOME FORM OF ADVISORIES MAY BE NEEDED FOR LATE TONIGHT
INTO FRIDAY.
EXPECT ACTIVITY ALONG THE BOUNDARY TO QUICKLY LIFT NORTHEAST
THROUGH THE REMAINDER OF THE FORECAST AREA DURING THE MORNING
HOURS...PERSISTING IN THE MOUNTAINS WELL INTO THE AFTERNOON WITH
MIXED PRECIPITATION CHANGING BACK TO SNOW AS COLDER AIR SHIFTS
BACK INTO THE REGION. COULD SEE SEVERAL INCHES OF ACCUMULATION
LATE IN THE DAY AS UPSLOPE FLOW KICKS IN BEHIND DEPARTING LOW.
ELSEWHERE RAIN AND MIXED PRECIPITATION WILL TAPPER TO SNOW SHOWERS
IN THE AFTERNOON.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A STRONG ARCTIC CD FNT MOVES THRU FRIDAY NGT BRINGING IN CD
CANADIAN AIR ON GUSTY W THEN NW WINDS. SHSN PSBL...THOUGH MOSTLY
CONFINED TO THE N/MT ZONES WHERE SOME ACCUMULATION PSBL. ELSEWHERE
DOWNSLOPE WINDS HELP TO MINIMIZE THE CHC OF ANY SHSN AND ALSO
DECREASES AMOUNT OF SKY COVER VERSUS THE N/MT ZONES. CD WX
DOMINATES THRU THE WEEKEND AS THE NW WIND FIELD SLOWLY EASES UP
WITH HIGH PRES APPROACHING FROM THE W. THE HIGH SETTLES OVER THE E
COAST MONDAY WITH FAIR BUT CONTINUED CD WX. THE HIGH MOVES OFF
SHORE TUESDAY ALLOWING SW FLOW TO BRING IN WARMER AIR. AN
APPROACHING CD FNT BRINGS A CHC OF -SHSN OR -SHRA TUESDAY AND
TUESDAY NGT. THE STRONG ARCTIC FNT MOVES BY FOR WEDNESDAY BRINGING
IN MORE VERY CD AND BLUSTERY WX.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR FRIDAY
NGT AND SATURDAY. USED GMOS FOR REST OF THE LONG TERM FCST... EXCEPT
USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND MIN TEMPS.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
SHORT TERM...IFR/LIFR CEILINGS/VSBY DEVELOPING TODAY AND
PERSISTING THROUGH FRIDAY MORNING...IMPROVING IN THE AFTERNOON.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...STRONG ARCTIC CD FNT
MOVES THRU FRIDAY NGT WITH SHSN PSBL ALONG WITH MVFR TO IFR
CIG/VSBY...THOUGH MOST ACTIVITY CONFINED TO THE N/MT AREAS.
STRONG GUSTY W THEN NW WINDS FRIDAY NGT.
&&
.MARINE...
SHORT TERM...GALE WARNING EXTENDED THROUGH FRIDAY NIGHT.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...WILL EXTEND THE GLW
THRU FRIDAY NGT WITH EVEN A FEW PEAK GUSTS OF STORM FORCE PSBL AS
STRONG W FLOW SETS UP BEHIND DEPARTING STRONG CD FNT AND TIGHT
PRES GRADIENT SETS UP AND IS ENHANCED BY STRONG CD AIR ADVECTION
OVER THE WARMER WATERS. WINDS SLOWLY LET UP AND SEAS SLOWLY
SUBSIDE AS HIGH PRES BUILDS IN FROM THE W OVER THE WEEKEND AND
SETTLES OVER THE E COAST ON MONDAY.
&&
.TIDES/COASTAL FLOODING...
THE ASTRONOMICAL HIGH TIDE IN PORTLAND IS 10.3 FT ANEAR 1 PM THIS
AFTERNOON. A STORM SURGE OF 1 TO 1.5 FT IS EXPECTED TDA. THIS
WOULD PUSH THE TIDE TO AROUND 11.5 FT AND POSSIBLY CLOSE TO THE 12
FOOT TIDAL FLOOD STAGE. AT THIS TIME THE TIDE IS EXPECTED TO STAY
BELOW 12 FT. HOWEVER, BUILDING SEAS FROM ONSHORE WINDS WILL LIKELY
CREATE UP TO MODERATE SPLASHOVER AND BEACH EROSION AROUND THE TIME OF HIGH
TIDE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR
MEZ007>009-012>014-018>022.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MEZ023>028.
COASTAL FLOOD ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MEZ023-024.
NH...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR
NHZ001>006-009-010.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NHZ007-008-013-014.
COASTAL FLOOD ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NHZ014.
MARINE...GALE WARNING UNTIL 7 AM EST SATURDAY FOR ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1244 PM EST THU JAN 12 2012
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.UPDATE...
LATEST RADAR IMAGERY IS SHOWING AN INCREASE IN AREAL COVERAGE OF
SNOWFALL ACROSS THE SOUTH CENTRAL PORTIONS OF THE CWA. GIVEN RADAR
TRENDS IN ADDITION TO SUPPORT FROM THE HRRR AND 12Z RUN OF THE LOCAL
WRF PLACING HIGHER QPF FARTHER EAST...HAVE OPTED TO PUT MENOMINEE
COUNTY IN A WINTER WEATHER ADVISORY. OBSERVATIONS ARE ALSO
INDICATING THAT SNOW TO LIQUID RATIOS ARE TRENDING SLIGHTLY HIGHER
IN THIS REGION. RESULTING SNOW TOTALS SHOULD BE 2 TO 5 INCHES...WITH
THE HIGHEST AMOUNTS ACROSS THE SOUTHERN HALF OF THE COUNTY. THE
HEAVIEST SNOW SHOULD FALL DURING THE AFTERNOON AND EVENING.
ELSEWHERE...COVERAGE OF THE SNOW REMAINS ON TRACK. A SLIGHT INCREASE
IN POPS WERE MADE FROM MUNISING TO ESCANABA FOR THIS AFTERNOON TO
ACCOUNT FOR THE CURRENT TRENDS AND SHARP EDGE OF THE PRECIPITATION
SHIELD. FATHER WEST...LAKE ENHANCEMENT ACROSS PORTIONS OF MARQUETTE
AND BARAGA COUNTY ARE HAS BECOME WELL ESTABLISHED OVER THE PAST
HOUR.
AS FOR TEMPERATURES...HIGHS HAVE LIKELY ALREADY OCCURRED ACROSS MUCH
OF THE CWA AS CONTINUOUS CAA AND THICK CLOUD COVER RESULT IN STEADY
OR SLIGHTLY DECREASING TEMPERATURES THROUGHOUT THE AFTERNOON.
PATCHY FOG ACROSS INTERIOR LOCATIONS OF THE EASTERN CWA SHOULD
DISSIPATE QUICKLY BY EARLY AFTERNOON. WINDS HAVE BECOME NORTHERLY AT
KERY AND VIS HAS INCREASED SLIGHTLY OVER THE LAST HOUR.
&&
.DISCUSSION...
WATER VAPOR LOOP SHOWS MID-UPR TROUGH DIGGING THROUGH THE CENTRAL
PLAINS. 3H JET MAX ROUNDING THE BASE OF THIS TROUGH AND ASSOC
DIVERGENCE IN LEFT EXIT REGION OF THIS JET WILL AID IN RAPID
DEEPENING OF SFC LOW/STORM SYSTEM OVER NRN OHIO ATTM. THIS STORM
SYSTEM AND FAIRLY DEEP MOISTURE WRAPPING AROUND IT WILL HELP BRING
SIGNIFICANT LAKE ENHANCED TO PORTIONS OF WEST AND NCNTRL UPPER MI
THROUGH FRIDAY.
TODAY...PERSISTENT 800-700 MB FGEN HAS HELPED SUSTAIN OCCASIONALLY
MODERATE SNOW FM MQT INTO DICKINSON COUNTY AS NOTED ON LATEST RADAR
LOOP. MODELS SHOW FGEN PERSISTING INTO THE EARLY AFTERNOON HRS OVER
GENERALLY THIS SAME AREA SO WOULD NOT BE SURPRISED TO SEE MODERATE
SNOW CONTINUE AT TIMES. WHILE WRN COUNTIES WILL BE FARTHER AWAY FROM
SYNOPTIC FORCING FROM STORM SYSTEM OVER THE CENTRAL GREAT
LAKES...CONVERGENT NRLY FLOW AND GREATER INSTABILITY FROM COLDER
850 MB TEMPS OF -12 TO -14C...ALONG WITH FAVORABLE DENDRITIC SNOW
GROWTH AND TERRAIN ENHANCED LIFT WILL AID MODERATE TO HEAVY SNOW
ACCUMULATIONS. EXPECT 2 TO 5 INCHES OVER THESE AREAS WHERE WINTER
STORMS WARNINGS ARE ALREADY IN PLACE. ALSO LOOK FOR HIGHER TERRAIN
OF BARAGA AND WRN MQT TO SEE 3 TO 5 INCHES OF ACCUMULATION WHERE
WEAK TO MODERATE SYNOPTIC FORCING AND UPSLOPE ENHANCED LIFT SHOULD
OVERCOME MARGINAL INSTABILITY...SO WARNING STILL LOOKS GOOD FOR
THESE COUNTIES AS WELL. KEPT ADVISORY GOING FOR SRN HOUGHTON...IRON
AND DICKINSON COUNTIES THROUGH TONIGHT ALTHOUGH I AM A BIT CONCERNED
THAT SNOW COULD TAPER OFF QUICKLY TONIGHT FOR DICKINSON AND IRON AND
SOME AREAS COULD HAVE A HARD TIME REACHING ADVISORY CRITERIA (2-4
INCHES/12 HR).
ISSUED A WINTER WX ADVISORY FOR ALGER COUNTY THIS AFTERNOON THROUGH
FRIDAY AS NORTHERLY FLOW AND INCREASING INSTABILITY FROM COLDER
TEMPS MOVING IN FROM THE WEST LATER THIS AFTERNOON AND TONIGHT
SHOULD GET LAKE ENHANCED SNOW PRETTY GOOD ESPECIALLY OVER THE WRN
HALF OF THE COUNTY. LOOK FOR TOTAL ACCUMS OF 6 TO 10 INCHES THIS
AFTERNOON THROUGH FRIDAY OVER ALGER.
CANCELLED WATCH FOR NRN SCHOOLCRAFT AND OPTED NOT TO ISSUE ANY
HEADLINES FOR NRN SCHOOLCRAFT OR LUCE COUNTY AS CYCLONIC NNE FLOW
WILL NOT BE A FAVORABLE FETCH ACROSS LAKE SUPERIOR TO RECEIVE
SIGNIFICANT LES ACCUMS THROUGH FRIDAY.
TONIGHT...WITH SFC LOW/850MB LOWS WELL SE OF THE AREA OVER LAKE
HURON...POTENTIAL FOR SIGNIFICANT SYNOPTIC SNOW LOOKS LIMITED AND
MODELS GENERALLY SHOW A DIMINISHING TREND TO SNOW OVER AREAS AWAY
FROM LAKE SUPERIOR BY THIS EVENING. EXPECT NO MORE THAN AN INCH
OR TWO OF SYNOPTIC SNOW TONIGHT. CLOSE TO LAKE SUPERIOR...IT WILL BE
A FAVORABLE SETUP FOR LAKE ENHANCEMENT IN THE N WIND FAVORED AREAS.
AS COLDER AIR SPREADS IN FROM THE WEST TONIGHT THE DENDRITIC SNOW
GROWTH ZONE (DGZ) WILL FALL FIRMLY INTO THE CONVECTIVE BOUNDARY
LAYER (FM 1-3 KFT OFF FCST SNDGS) WHILE TERRAIN ENHANCED UPWARD
MOTION LAYER WILL ALSO AID LIFT IN THIS LYR. INCREASING SNOW-TO-WATER
RATIOS SHOULD RESULT IN MDT/POSSIBLY HVY SNOW ACCUMULATIONS W AND
NCNTRL. COMBINED WITH GUSTY WINDS...BLOWING AND DRIFTING SNOW WILL
ALSO ADD TO HAZARDOUS CONDITIONS ON AREA ROADS. WOULD NOT BE
SURPRISED TO SEE 6-8 INCH AMOUNTS TONIGHT WHERE TERRAIN ENHANCEMENT
IS MAXIMIZED (AROUND KIWD AND HURON MTNS).
FRIDAY...MUCH DRIER AIR WILL MAKE SHARP INROADS FROM W TO E FRI WITH
INVERSION HGTS FALLING AT OR BLO 3KFT. AS A RESULT...SNOW
INTENSITY WILL DIMINISH SIGNIFICANTLY FROM W TO E THRU THE DAY (W IN
THE MORNING...E IN THE AFTN). ALTHOUGH CONVECTIVE LAYER WILL BECOME
SHALLOW...DGZ WILL STILL BE CENTERED WITHIN THE CBL...ALLOWING FOR
LIGHTER FLUFFY ACCUMULATIONS TO CONTINUE.
FRI NIGHT INTO SATUURDAY...HIGH PRES RIDGE SLIPPING INTO THE W FRI
NIGHT MAY ALLOW FOR A VERY COLD NIGHT IF SKIES CLEAR. LOWERED TEMPS
WELL INTO THE SINGLE DIGITS BLO ZERO OVER THE WRN INTERIOR WHERE
THERE SHOULD BE PARTIAL CLEARING...BUT IT COULD REACH -10F OR COLDER
IF SKIES CLEAR COMPLETELY FOR A FEW HRS GIVEN FRESH SNOW COVER. SOME
LIGHT LES SHOULD CONTINUE INTO FRI NIGHT INTO SAT FOR PORTIONS OF
THE KEWEENAW AND NCNTRL WITH LIGHT CONVERGENT ONSHORE WINDS EXPECTED.
SUN THRU WED...ARCTIC AIR WILL BEGIN POOLING OVER CANADA DURING THIS
PERIOD AS RIDGE AMPLIFIES N THRU WRN ALASKA/BERING SEA INTO THE
ARCTIC. 00Z MODELS NOW ADVERTISE A SERIES OF CLIPPER SHORTWAVES
ROTATING THROUGH THE UPPER GREAT LAKES NEXT WEEK ROTATING AROUND
BROAD POLAR VORTEX ENCOMPASSING MUCH OF NRN CANADA. FIRST SHORTWAVE
MOVING THROUGH ON TUE COULD USHER IN 850 MB TEMPS COLDER THAN -20F
TUE NIGHT AS NOTED ON THE 00Z ECMWF AND THE SECOND SHORTWAVE MOVING
THROUGH WED NIGHT COULD BRING IN 850 MB TEMPS BTWN -25 AND
-30F...THE COLDEST AIR OF THE SEASON THUS FAR. WILL NEED TO KEEP A
CLOSE EYE ON MODEL TRENDS FOR NEXT WEEK AS MORE LAKE EFFECT SNOW
COULD BE IN STORE FOR NW SNOW BELTS BEGINNING TUE AND CONTINUING
INTO THU....AND WIND CHILL HEADLINES COULD BE A REAL POSSIBILITY FOR
SOME AREAS MID TO LATE WEEK.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
STEADY SNOW HAS SPREAD ACROSS CENTRAL UPPER MICHIGAN WHILE A SLIGHT
DECREASE IN SNOW COVERAGE HAS APPEARED ACROSS THE WEST WHERE
TRANSISITION TO LAKE EFFECT SNOW IS UNDERWAY. ALL LOCATIONS SHOULD
REMAIN PREDOMINATELY AT IFR CONDITIONS INTO THIS EVENING. KCMX MAY
FALL TO VLIFR AS HEAVIER LAKE EFFECT SNOW SHOWERS DECREASE VIS. BY
THIS EVENING...DRIER AIR AND A SLIGHT VEERING OF THE WINDS AT KCMX
SHOULD LIMIT HEAVIER SNOW. KIWD SHOULD ALSO SEE CONSISTENT LAKE
EFFECT SNOW THROUGH THE NIGHT BEFORE DRIER AIR MOVES IN. STEADY SNOW
AT KSAW WILL GIVE WAY TO HEAVIER SNOW DURING THE OVERNIGHT HOURS AS
LAKE ENHANCEMENT INCREASES.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/..
LOW PRESSURE DEEPENING OVER THE CENTRAL GREAT LAKES THROUGH TONIGHT
RESULTS IN WINDS OUT OF THE NORTH INCREASING TO GALES LATER TODAY
THROUGH MUCH OF FRIDAY. OTHER HAZARD OF NOTE IS HEAVY FREEZING SPRAY
THAT WILL DEVELOP OVER MOST OF THE LAKE LATE TODAY THROUGH FRIDAY
MORNING. ALL HAZARDS WILL SUBSIDE BY FRIDAY EVENING. WINDS THEN WILL
DECREASE TO LESS THAN 25 KTS THROUGH MOST OF THE WEEKEND. SOUTH
WINDS PICK UP AGAIN SUNDAY NIGHT AHEAD OF LOW PRESSURE TROUGH MOVING
ACROSS. STRONGEST WINDS WILL BE OVER THE EASTERN HALF OF THE LAKE.
WINDS BECOME NORTHWESTERLY LATER MONDAY INTO TUESDAY WITH GALE FORCE
WINDS POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ FRIDAY FOR
MIZ010-084.
WINTER STORM WARNING UNTIL 1 PM EST /NOON CST/ FRIDAY FOR
MIZ001>003-009.
WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR MIZ006.
WINTER STORM WARNING UNTIL 7 PM EST FRIDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 6 AM CST FRIDAY FOR MIZ011-012.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THIS EVENING TO 1 PM EST FRIDAY FOR
LSZ267.
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 PM EST
FRIDAY FOR LSZ266.
GALE WARNING UNTIL 1 PM EST FRIDAY FOR LSZ244-245-263>266.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ THIS
EVENING TO 1 PM EST /NOON CST/ FRIDAY FOR LSZ162-240>244-
263-264.
GALE WARNING UNTIL 1 PM EST FRIDAY FOR LSZ248>250.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...TK
DISCUSSION...VOSS
AVIATION...TK
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1140 AM EST THU JAN 12 2012
.UPDATE...
LATEST RADAR IMAGERY IS SHOWING AN INCREASE IN AREAL COVERAGE OF
SNOWFALL ACROSS THE SOUTH CENTRAL PORTIONS OF THE CWA. GIVEN RADAR
TRENDS IN ADDITION TO SUPPORT FROM THE HRRR AND 12Z RUN OF THE LOCAL
WRF PLACING HIGHER QPF FARTHER EAST...HAVE OPTED TO PUT MENOMINEE
COUNTY IN A WINTER WEATHER ADVISORY. OBSERVATIONS ARE ALSO
INDICATING THAT SNOW TO LIQUID RATIOS ARE TRENDING SLIGHTLY HIGHER
IN THIS REGION. RESULTING SNOW TOTALS SHOULD BE 2 TO 5 INCHES...WITH
THE HIGHEST AMOUNTS ACROSS THE SOUTHERN HALF OF THE COUNTY. THE
HEAVIEST SNOW SHOULD FALL DURING THE AFTERNOON AND EVENING.
ELSEWHERE...COVERAGE OF THE SNOW REMAINS ON TRACK. A SLIGHT INCREASE
IN POPS WERE MADE FROM MUNISING TO ESCANABA FOR THIS AFTERNOON TO
ACCOUNT FOR THE CURRENT TRENDS AND SHARP EDGE OF THE PRECIPITATION
SHIELD. FATHER WEST...LAKE ENHANCEMENT ACROSS PORTIONS OF MARQUETTE
AND BARAGA COUNTY ARE HAS BECOME WELL ESTABLISHED OVER THE PAST
HOUR.
AS FOR TEMPERATURES...HIGHS HAVE LIKELY ALREADY OCCURRED ACROSS MUCH
OF THE CWA AS CONTINUOUS CAA AND THICK CLOUD COVER RESULT IN STEADY
OR SLIGHTLY DECREASING TEMPERATURES THROUGHOUT THE AFTERNOON.
PATCHY FOG ACROSS INTERIOR LOCATIONS OF THE EASTERN CWA SHOULD
DISSIPATE QUICKLY BY EARLY AFTERNOON. WINDS HAVE BECOME NORTHERLY AT
ERY AND VIS HAS INCREASED SLIGHTLY OVER THE LAST HOUR.
&&
PREV DISCUSSION...ISSUED AT 649 AM EST THU JAN 12 2012...
.DISCUSSION...
WATER VAPOR LOOP SHOWS MID-UPR TROUGH DIGGING THROUGH THE CENTRAL
PLAINS. 3H JET MAX ROUNDING THE BASE OF THIS TROUGH AND ASSOC
DIVERGENCE IN LEFT EXIT REGION OF THIS JET WILL AID IN RAPID
DEEPENING OF SFC LOW/STORM SYSTEM OVER NRN OHIO ATTM. THIS STORM
SYSTEM AND FAIRLY DEEP MOISTURE WRAPPING AROUND IT WILL HELP BRING
SIGNIFICANT LAKE ENHANCED TO PORTIONS OF WEST AND NCNTRL UPPER MI
THROUGH FRIDAY.
TODAY...PERSISTENT 800-700 MB FGEN HAS HELPED SUSTAIN OCCASIONALLY
MODERATE SNOW FM MQT INTO DICKINSON COUNTY AS NOTED ON LATEST RADAR
LOOP. MODELS SHOW FGEN PERSISTING INTO THE EARLY AFTERNOON HRS OVER
GENERALLY THIS SAME AREA SO WOULD NOT BE SURPRISED TO SEE MODERATE
SNOW CONTINUE AT TIMES. WHILE WRN COUNTIES WILL BE FARTHER AWAY FROM
SYNOPTIC FORCING FROM STORM SYSTEM OVER THE CENTRAL GREAT
LAKES...CONVERGENT NRLY FLOW AND GREATER INSTABILITY FROM COLDER
850 MB TEMPS OF -12 TO -14C...ALONG WITH FAVORABLE DENDRITIC SNOW
GROWTH AND TERRAIN ENHANCED LIFT WILL AID MODERATE TO HEAVY SNOW
ACCUMULATIONS. EXPECT 2 TO 5 INCHES OVER THESE AREAS WHERE WINTER
STORMS WARNINGS ARE ALREADY IN PLACE. ALSO LOOK FOR HIGHER TERRAIN
OF BARAGA AND WRN MQT TO SEE 3 TO 5 INCHES OF ACCUMULATION WHERE
WEAK TO MODERATE SYNOPTIC FORCING AND UPSLOPE ENHANCED LIFT SHOULD
OVERCOME MARGINAL INSTABILITY...SO WARNING STILL LOOKS GOOD FOR
THESE COUNTIES AS WELL. KEPT ADVISORY GOING FOR SRN HOUGHTON...IRON
AND DICKINSON COUNTIES THROUGH TONIGHT ALTHOUGH I AM A BIT CONCERNED
THAT SNOW COULD TAPER OFF QUICKLY TONIGHT FOR DICKINSON AND IRON AND
SOME AREAS COULD HAVE A HARD TIME REACHING ADVISORY CRITERIA (2-4
INCHES/12 HR).
ISSUED A WINTER WX ADVISORY FOR ALGER COUNTY THIS AFTERNOON THROUGH
FRIDAY AS NORTHERLY FLOW AND INCREASING INSTABILITY FROM COLDER
TEMPS MOVING IN FROM THE WEST LATER THIS AFTERNOON AND TONIGHT
SHOULD GET LAKE ENHANCED SNOW PRETTY GOOD ESPECIALLY OVER THE WRN
HALF OF THE COUNTY. LOOK FOR TOTAL ACCUMS OF 6 TO 10 INCHES THIS
AFTERNOON THROUGH FRIDAY OVER ALGER.
CANCELLED WATCH FOR NRN SCHOOLCRAFT AND OPTED NOT TO ISSUE ANY
HEADLINES FOR NRN SCHOOLCRAFT OR LUCE COUNTY AS CYCLONIC NNE FLOW
WILL NOT BE A FAVORABLE FETCH ACROSS LAKE SUPERIOR TO RECEIVE
SIGNIFICANT LES ACCUMS THROUGH FRIDAY.
TONIGHT...WITH SFC LOW/850MB LOWS WELL SE OF THE AREA OVER LAKE
HURON...POTENTIAL FOR SIGNIFICANT SYNOPTIC SNOW LOOKS LIMITED AND
MODELS GENERALLY SHOW A DIMINISHING TREND TO SNOW OVER AREAS AWAY
FROM LAKE SUPERIOR BY THIS EVENING. EXPECT NO MORE THAN AN INCH
OR TWO OF SYNOPTIC SNOW TONIGHT. CLOSE TO LAKE SUPERIOR...IT WILL BE
A FAVORABLE SETUP FOR LAKE ENHANCEMENT IN THE N WIND FAVORED AREAS.
AS COLDER AIR SPREADS IN FROM THE WEST TONIGHT THE DENDRITIC SNOW
GROWTH ZONE (DGZ) WILL FALL FIRMLY INTO THE CONVECTIVE BOUNDARY
LAYER (FM 1-3 KFT OFF FCST SNDGS) WHILE TERRAIN ENHANCED UPWARD
MOTION LAYER WILL ALSO AID LIFT IN THIS LYR. INCREASING SNOW-TO-WATER
RATIOS SHOULD RESULT IN MDT/POSSIBLY HVY SNOW ACCUMULATIONS W AND
NCNTRL. COMBINED WITH GUSTY WINDS...BLOWING AND DRIFTING SNOW WILL
ALSO ADD TO HAZARDOUS CONDITIONS ON AREA ROADS. WOULD NOT BE
SURPRISED TO SEE 6-8 INCH AMOUNTS TONIGHT WHERE TERRAIN ENHANCEMENT
IS MAXIMIZED (AROUND KIWD AND HURON MTNS).
FRIDAY...MUCH DRIER AIR WILL MAKE SHARP INROADS FROM W TO E FRI WITH
INVERSION HGTS FALLING AT OR BLO 3KFT. AS A RESULT...SNOW
INTENSITY WILL DIMINISH SIGNIFICANTLY FROM W TO E THRU THE DAY (W IN
THE MORNING...E IN THE AFTN). ALTHOUGH CONVECTIVE LAYER WILL BECOME
SHALLOW...DGZ WILL STILL BE CENTERED WITHIN THE CBL...ALLOWING FOR
LIGHTER FLUFFY ACCUMULATIONS TO CONTINUE.
FRI NIGHT INTO SATUURDAY...HIGH PRES RIDGE SLIPPING INTO THE W FRI
NIGHT MAY ALLOW FOR A VERY COLD NIGHT IF SKIES CLEAR. LOWERED TEMPS
WELL INTO THE SINGLE DIGITS BLO ZERO OVER THE WRN INTERIOR WHERE
THERE SHOULD BE PARTIAL CLEARING...BUT IT COULD REACH -10F OR COLDER
IF SKIES CLEAR COMPLETELY FOR A FEW HRS GIVEN FRESH SNOW COVER. SOME
LIGHT LES SHOULD CONTINUE INTO FRI NIGHT INTO SAT FOR PORTIONS OF
THE KEWEENAW AND NCNTRL WITH LIGHT CONVERGENT ONSHORE WINDS EXPECTED.
SUN THRU WED...ARCTIC AIR WILL BEGIN POOLING OVER CANADA DURING THIS
PERIOD AS RIDGE AMPLIFIES N THRU WRN ALASKA/BERING SEA INTO THE
ARCTIC. 00Z MODELS NOW ADVERTISE A SERIES OF CLIPPER SHORTWAVES
ROTATING THROUGH THE UPPER GREAT LAKES NEXT WEEK ROTATING AROUND
BROAD POLAR VORTEX ENCOMPASSING MUCH OF NRN CANADA. FIRST SHORTWAVE
MOVING THROUGH ON TUE COULD USHER IN 850 MB TEMPS COLDER THAN -20F
TUE NIGHT AS NOTED ON THE 00Z ECMWF AND THE SECOND SHORTWAVE MOVING
THROUGH WED NIGHT COULD BRING IN 850 MB TEMPS BTWN -25 AND
-30F...THE COLDEST AIR OF THE SEASON THUS FAR. WILL NEED TO KEEP A
CLOSE EYE ON MODEL TRENDS FOR NEXT WEEK AS MORE LAKE EFFECT SNOW
COULD BE IN STORE FOR NW SNOW BELTS BEGINNING TUE AND CONTINUING
INTO THU....AND WIND CHILL HEADLINES COULD BE A REAL POSSIBILITY FOR
SOME AREAS MID TO LATE WEEK.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
STEADY AND WIDESPREAD SNOW WL TRANSITION TO LAKE EFFECT SNOW SHOWERS
BY TONIGHT. IFR CONDITIONS WILL BE PROMINENT THROUGH THE PERIOD.
AREAS FAVORED BY NORTHERLY WINDS...KIWD AND KSAW...WILL HAVE BEST
CHANCE TO SEE PROLONGED CONDITIONS BLO ALTERNATE LANDING MINS. DUE
TO STRONG GUSTY NORTHERLY WINDS AND HEAVIER SNOW/BLOWING SNOW THERE
IS A RISK THAT CONDITIONS AT KSAW MAY NEAR AIRFIELD MINIMUMS LATE
TODAY THROUGH MUCH OF TONIGHT. CONDITIONS WILL BEGIN TO IMPROVE AT
ALL SITES BY FRIDAY AFTERNOON.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/..
LOW PRESSURE DEEPENING OVER THE CENTRAL GREAT LAKES THROUGH TONIGHT
RESULTS IN WINDS OUT OF THE NORTH INCREASING TO GALES LATER TODAY
THROUGH MUCH OF FRIDAY. OTHER HAZARD OF NOTE IS HEAVY FREEZING SPRAY
THAT WILL DEVELOP OVER MOST OF THE LAKE LATE TODAY THROUGH FRIDAY
MORNING. ALL HAZARDS WILL SUBSIDE BY FRIDAY EVENING. WINDS THEN WILL
DECREASE TO LESS THAN 25 KTS THROUGH MOST OF THE WEEKEND. SOUTH
WINDS PICK UP AGAIN SUNDAY NIGHT AHEAD OF LOW PRESSURE TROUGH MOVING
ACROSS. STRONGEST WINDS WILL BE OVER THE EASTERN HALF OF THE LAKE.
WINDS BECOME NORTHWESTERLY LATER MONDAY INTO TUESDAY WITH GALE FORCE
WINDS POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ FRIDAY FOR
MIZ010-084.
WINTER STORM WARNING UNTIL 1 PM EST /NOON CST/ FRIDAY FOR
MIZ001>003-009.
WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR MIZ006.
WINTER STORM WARNING UNTIL 7 PM EST FRIDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 6 AM CST FRIDAY FOR MIZ011-012.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THIS EVENING TO 1 PM EST FRIDAY FOR
LSZ267.
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 PM EST
FRIDAY FOR LSZ266.
GALE WARNING UNTIL 1 PM EST FRIDAY FOR LSZ244-245-263>266.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ THIS
EVENING TO 1 PM EST /NOON CST/ FRIDAY FOR LSZ162-240>244-
263-264.
GALE WARNING FROM 3 PM THIS AFTERNOON TO 1 PM EST FRIDAY FOR
LSZ248>250.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...TK
DISCUSSION...VOSS
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1255 PM EST THU JAN 12 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL CAUSE BREEZY
WESTERLY WINDS ACROSS THE CAROLINAS AND SOUTHERN VIRGINIA TODAY. A
POLAR COLD FRONT WILL CROSS THE REGION TONIGHT. MUCH COOLER AIR WILL
SETTLE OVER THE AREA FRIDAY AND LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM THURSDAY...
DEEP BUT TEMPORARY WEST-SOUTHWESTERLY FLOW OBSERVED OVER CENTRAL NC
THIS MORNING AS ONE LOW PRESSURE SYSTEM IS LIFTING TOWARD NEW
ENGLAND AND A SECOND CLIPPER LOW IS DIVING THROUGH THE MIDWEST
STATES. THE AIRMASS AROUND THE SOUTHEAST IS FAIRLY UNIFORM...SO
HIGHS TODAY WILL MOSTLY BE DEPENDING ON MIXING AS GRADIENT WINDS
INCREASE AHEAD OF THE APPROACHING DEEP CLIPPER SYSTEM. FORECAST
SOUNDINGS SHOW MIXING TO AROUND 900MB...WHICH MAY BE SLIGHTLY
UNDERDONE GIVEN THAT WINDS ARE ALREADY INCREASING TO 12-15KT AND
WILL EVENTUALLY GUST TO NEAR 25KT THIS AFTERNOON. A RIBBON OF
STRATUS TRAPPED BELOW THE SUBSIDENCE INVERSION OVER THE FOOTHILLS
AND WESTERN PIEDMONT HAS RESISTED MIXING SO FAR...AND ALSO A LARGE
AREA IF STRATUS IS ADVANCING THROUGH UPSTATE SC AND MAY BLEED INTO
AREAS NEAR THE YADKIN RIVER. CLOUD COVER WILL BE ADJUSTED OVER THE
WESTERN COUNTIES BASED ON SOME OF THE HRRR AVIATION GUIDANCE AND
TEMPS MAY ULTIMATELY BE HELD DOWN A COUPLE OF DEGREES IN THE WEST.
EXPECT HIGHS OF 58-65 NORTHWEST TO SOUTHEAST. -SMITH
AS THE UPPER TROUGH AND SFC COLD FRONT CROSSES THE MTNS THIS
EVENING...STRONG FRONTOGENETIC FORCING WITHIN UPPER JET EXIT REGION
WILL SUPPORT A BAND OF SHALLOW CONVECTION THAT WILL QUICKLY MOVE
EAST ACROSS CENTRAL NC BETWEEN 00 TO 06Z. MOISTURE WILL BE LIMITED
WITH EXPECTED SCATTERED SHOWERS TENDING TO DRY UP/DISSIPATE AS THEY
ADVANCE EAST OFF THE HIGHER TERRAIN AS FLOW QUICKLY BECOMES WESTERLY
WITH STRONG DRY COLD AIR ADVECTION ENSUING. ANY PRECIP WILL BE ALL
LIQUID WITH COLD AIR TRAILING THE EXITING SHALLOW MOIST LAYER. SKIES
SHOULD CLEAR OFF MIDNIGHT WITH CAA PLUNGING TEMPERATURES DOWN INTO
THE LOWER 30S NORTHWEST TO MID/UPPER 30S SOUTHEAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 315 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
A TIGHT PRESSURE GRADIENT WILL CONTINUE ON FRIDAY BETWEEN THE
DEEPENING LOW PRESSURE OVER NEW ENGLAND AND SURFACE HIGH PRESSURE
OVER THE GULF COAST STATES. INVERSELY TO TODAY...THESE WINDS WILL
EXACERBATE THE BUILDING ARCTIC AIRMASS AS LOW-LEVEL THICKNESSES 12Z
FRIDAY MORNING ARE FORECAST TO START OUT 30 METERS BELOW
NORMAL...SUPPORTING HIGHS IN THE LOWER 40S NW TO UPPER 40S
SOUTHEAST...WITH BLUSTERY WESTERLY WINDS PRODUCING WIND CHILLS
OF 35 TO 40. PRESSURE GRADIENT RELAXES FRIDAY EVENING/NIGHT AS LOW
OVER NEW ENGLAND CONTINUES TO MOVE AWAY. COLD OVERNIGHT LOWS IN THE
IN THE LOWER TO MID 20S.
SATURDAY...L/W TROUGH OVER THE EASTERN HALF OF THE U.S WILL MAINTAIN
COOLER THAN NORMAL CONDITIONS ACROSS OUR REGION. 850MB THERMAL
TROUGH LIES ACROSS THE REGION SATURDAY WITH 850MB TEMPS MINUS
6-MINUS 8 DEGREES C. THICKNESSES 30-35M BELOW NORMAL WHICH WOULD
YIELD MAX TEMPS NO HIGHER THAN THE UPPER 30S TO NEAR 40 IN THE
PIEDMONT. ADJUSTING FOR POTENTIAL AIR MASS MODIFICATION...EXPECT MAX
TEMPS IN THE LOW-MID 40S OVER THE PIEDMONT AND NORTHERN COASTAL
PLAIN..AND UPPER 40S ACROSS THE FAR SOUTH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 315 AM THURSDAY...
SATURDAY NIGHT...MODEL GUIDANCE HAS TRENDED FARTHER SOUTH WITH A
VORT MAX IN THE NW FLOW TRAVERSING SEWD ON THE BACK SIDE OF THE
TROUGH. DUE TO THE MORE SOUTHWARD PATH OF THE VORT MAX INTO THE BASE
OF THE UPPER TROUGH OVER OUR REGION...WE HAVE A BETTER CHANCE OF
SEEING MORE CLOUDS AND POSSIBLY SOME LIGHT PRECIP. 00Z GFS
RH/TEMP/LIFT CROSS SECTION FOR 06Z SUNDAY DOES DEPICT ADEQUATE
MOISTURE AND LIFT IN THE FAVORED ICE NUCLEATION REGION TO GENERATE
SNOWFLAKES ALOFT. HOWEVER THE LIFT DOES NOT EXTEND DOWN INTO THE
LOWEST 8K FT OF THE ATMOSPHERE PLUS THE SUBCLOUD LAYER IS QUITE DRY
SUGGESTING A HIGH PROBABILITY OF EVAPORATION. PARTIAL THICKNESSES
SUGGEST THAT ANY PRECIP THAT DOES REACH THE SURFACE WOULD BE LIGHT
SNOW. SINCE THIS IS THE FIRST ITERATION OF THIS POSSIBLE SCENARIO BY
THE MODELS...AND THE NEAR SURFACE CONDITIONS NOT IDEAL FOR
PRECIP...WILL REFRAIN FROM MENTIONING PRECIP IN THE FORECAST AT THIS
TIME. IF PRECIP WERE TO OCCUR...WOULD EXPECT NOTHING MORE THAN A FEW
SNOW FLURRIES...MAINLY LATE SATURDAY EVENING INTO THE OVERNIGHT
HOURS. DUE TO THE INCREASE IN CLOUD COVERAGE...EXPECT MIN
TEMPS TO BE A COUPLE OF DEGREES WARMER THAN FRIDAY NIGHT. MOST
PLACES SHOULD BE IN THE UPPER 20S.
SUNDAY INTO MONDAY...STRONG SUBSIDENCE IN THE WAKE OF THE EXITING
VORT MAX SUNDAY MORNING WILL LEAD TO CLEARING SKIES WITH SUNNY SKIES
EXPECTED AREAWIDE BY EARLY AFTERNOON. NW FLOW AT 850MB IN THE WAKE
OF THE SYSTEM SUNDAY DEPICT NEUTRAL ADVECTION AT THIS TIME.
LINGERING EFFECTS OF 850MB THERMAL TROUGH OVER THE REGION SHOULD
YIELD MAX TEMPS SLIGHTLY BELOW NORMAL. AFTERNOON TEMPS IN THE
MID-UPPERS 40S PROJECTED.
SURFACE RIDGE OVER THE REGION SUNDAY NIGHT SHOULD CREATE IDEAL
CONDITIONS FOR RADIATIONAL COOLING. MIN TEMPS MID 20S WITH LOWER
20S POSSIBLE IN THE NORMALLY COLDER LOCALES.
MODEST RECOVERY BEGINS MONDAY AS SURFACE RIDGE SHIFTS EAST AND
RETURN FLOW COMMENCES LATE IN THE DAY. AIR MASS MODIFICATION SHOULD
RESULT IN MAX TEMPS CLOSE TO NORMAL FOR MID JANUARY...UPPER 40S TO
THE LOWER 50S.
MONDAY NIGHT INTO TUESDAY...MODELS HAVE TRENDED WETTER WITH THIS
PARTICULAR MODEL RUN. BOTH THE 00Z GFS AND 00Z ECMWF PAINT LIGHT
PRECIP OVER CENTRAL NC MONDAY NIGHT IN THE LOW LEVEL WAA REGIME.
ISENTROPIC UPGLIDE APPEARS TO BE BEST IN THE 285-290K LAYER. WHILE
CANNOT RULE SPOTTY PRECIP...LOW LEVEL AIR MASS WILL BE QUITE DRY
MONDAY WITH DEWPOINTS IN THE TEENS. THUS THE PRECIP GENERATED BY THE
MODELS MAY ACTUALLY GO INTO MOISTENING THE SUB CLOUD LAYER TO
SATURATION. WILL KEEP POPS BELOW 20 PERCENT BUT DID RAISE MIN TEMPS
A COUPLE OF DEGREES DUE TO THICKENING CLOUDS.
NEXT MID-UPPER LEVEL S/W IN THE BROAD TROUGH OVER THE EASTERN U.S.
PROJECTED TO ADVANCE EAST FROM THE MID MS VALLEY INTO THE OH VALLEY
TUESDAY. THIS FEATURE WILL INDUCE WSW FLOW ALOFT. MEANWHILE N-S
ORIENTATION OF THE SURFACE RIDGE OFF THE EASTERN SEABOARD YIELDS A
LOW LEVEL S-SW FLOW OVER THE CAROLINAS ORIGINATING FROM THE CENTRAL
GULF. THIS SUGGEST A SHOT OF LOW LEVEL MOISTURE TRANSPORT INTO OUR
REGION AHEAD OF THE S/W AND ATTENDANT SURFACE FRONT. SINCE WE ARE
TALKING ABOUT DAY6/7...WILL ADJUST POP ONLY A TAD TO ABOUT 30
PERCENT IN THE WEST AND MAINTAIN A SLIGHT CHANCE IN THE EAST. MODEL
TIMING SUGGEST HIGHEST THREAT FOR PRECIP TUESDAY AFTERNOON-EARLY
TUESDAY NIGHT. SYSTEM EXITS REGION WEDNESDAY LEADING TO CLEARING
SKIES. TEMPS BEHIND FRONT WILL BE SLIGHTLY COOLER BUT NOT
OUTRAGEOUSLY COLD SINCE HIGH APPEARS TO BE OF PACIFIC ORIGIN WITH
SOME MODIFIED CP INFLUENCE.
&&
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
AS OF 1255 PM THURSDAY...
STRATUS OVER THE WESTERN PIEDMONT THIS MORNING HAS BEEN SLOW TO LIFT
AND SCATTER...SO SOME LOW STRATUS/STRATOCU ARE AFFECTING AREAS IN
AROUND THE KINT/KGSO TERMINALS. FURTHER SOUTH...STRATUS OVER SC HAS
MOVED RATHER QUICKLY TO THE NORTH-NORTHEAST...AND SOME MVFR CEILINGS
OF 2-3KT ARE BEING REPORTED OVER THE SOUTHERN PIEDMONT AND
SANDHILLS. DUE TO THIS... THE CURRENT TAF PACKAGE WILL MAINTAIN
MVFR CEILINGS AT KGSO/KINT/KFAY INTO THE EVENING HOURS AS INCREASING
MOISTURE AND POSSIBLY A FEW SHOWERS ASSOCIATED WITH AN UPPER
DISTURBANCE APPROACHING FROM THE NORTHWEST SHOULD KEEP CEILINGS
PREDOMINATELY BELOW 3K FT. ANY SHOWERS AND MVFR CEILINGS WILL
EVENTUALLY REACH KRDU AND KRWI LATE THIS EVENING...BUT SKIES ARE
EXPECTED TO CLEAR FROM WEST TO EAST AFTER MIDNIGHT AS THE
AFOREMENTIONED DISTURBANCE SWINGS ACROSS THE AREA. BRISK
WEST-SOUTHWESTERLY WINDS OF 12-15KT AND GUSTS INTO THE LOW TO MID
20KT RANGE WILL LIKELY CONTINUE INTO THE OVERNIGHT HOURS...SWITCHING
TO MORE WESTERLY ON FRIDAY BUT REMAINING GUSTY.
OUTLOOK...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD...OUTSIDE OF A BRIEF
PERIOD MVFR CEILINGS SATURDAY NIGHT AS ANOTHER CLIPPER SYSTEM SWINGS
THROUGH THE REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...CBL/SMITH
SHORT TERM...CBL/WSS
LONG TERM...WSS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1111 AM CST THU JAN 12 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...NORTH WINDS IN THE 15 TO 25 KNOT RANGE WITH A FEW
HIGHER GUSTS TO 30KTS WILL REMAIN POSSIBLE THROUGH THIS AFTERNOON.
HOWEVER THE GENERAL TREND WILL BE GRADUALLY DOWNWARD IN SPEED FOR THE
REST OF THE DAY. WINDS WILL STAY STEADY OUT OF THE NORTH THIS
EVENING BEFORE LARGELY DROPPING OFF BEFORE MIDNIGHT. SKIES WILL
CONTINUE TO CLEAR OUT FROM NORTHWEST TO SOUTHEAST WITH ONLY HIGH
CLOUDS REMAINING. VFR CONDITIONS EXPECTED THROUGH THE NEXT 24
HOURS. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 839 AM CST THU JAN 12 2012/
DISCUSSION...FORECAST IN GENERALLY GOOD SHAPE THIS MORNING AND
HAVE MADE LITTLE OVERALL CHANGE. LATEST OBS AND PROFILER DATA
COUPLED WITH 12Z RAOB APPEAR TO SHOW A RELATIVE MAXIMUM IN THE LOW
LEVEL PRESSURE GRADIENT FROM AROUND PORT ISABEL NORTHWARD TO NEAR
VICTORIA TEXAS. LATEST RUC SEEMS TO HANDLE THIS VERY WELL SHOWING
A PERIOD OVER THE NEXT COUPLE OF HOURS WHERE OCCASIONAL GUSTS TO
AROUND 40 MPH WILL BE POSSIBLE OVER LAND...WITH FREQUENT GALES
OVER THE COASTAL WATERS. NAM/RUC CROSS SECTIONS SHOW THE VERTICAL
PRESSURE GRADIENT AND RESULTANT DOWNWARD FORCING RELAXING AS THE
BOUNDARY LAYER EXPANDS DUE TO SURFACE HEATING THIS MORNING AND
AS A RESULT PROGS EASING WINDS AFTER ABOUT 18Z WHICH APPEARS VERY
REASONABLE. HAVE ISSUED A SHORT TERM FORECAST TO MENTION THE INCREASED
WIND POTENTIAL FOR THE NEXT COUPLE OF HOURS...BUT FALLING BELOW
ADVISORY CRITERIA FOR NOW. SEE FIRE WEATHER DISCUSSION BELOW FOR
CHANGES TO THE FIRE WEATHER FORECAST PACKAGE. /68-JGG/
FIRE WEATHER...SEEING MORE FREQUENT SUSTAINED WINDS OVER 25 MPH
BEGINNING TO COME IN THIS MORNING SLIGHTLY FURTHER WEST THAN
ORIGINALLY ANTICIPATED. WITH RH EXPECTED TO WELL EXCEED CRITICAL
THRESHOLDS...AND WINDS SHOWING SIGNS OF ALSO DOING SO HAVE
EXPANDED THE RED FLAG WARNING TO INCLUDE ALL BUT ZAPATA COUNTY IN
OUR CWA UNTIL 4PM THIS AFTERNOON. /68/
PREV DISCUSSION... /ISSUED 545 AM CST THU JAN 12 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...MVFR CONDITIONS WITH BKN020 LOW CLOUDS NEAR THE COAST
WITH THE RECENT PASSAGE OF A COLD FRONT. SKC UPSTREAM AND EXPECT
SOME CLEARING THIS MORNING BEFORE THICKER LOW CLOUDS DEVELOP
TONIGHT. OTHERWISE...BREEZY AND GUSTY NORTH WINDS TODAY...
DECREASING TONIGHT.
PREV DISCUSSION... /ISSUED 306 AM CST THU JAN 12 2012/
SHORT TERM /TODAY THROUGH FRIDAY/...
A COLD FRONT WILL PRETTY MUCH HAVE ARRIVED THROUGH THE CWA AS WE
OPEN THE FORECAST TODAY. BEHIND THE FRONT...AN AIR MASS WITH
MARITIME POLAR CHARACTERISTICS WILL BE ARRIVING ALONG A LINE THAT
STRETCHED NORTHWEST INTO THE PACIFIC NORTHWEST. WE ARE LOOKING FOR
BREEZY AND GUSTY NORTH WINDS EARLY ON TODAY...ESPECIALLY IN COASTAL
AREAS...WITH BKN LOW CLOUDS ALONG THE COLD FRONT THIS MORNING GIVING
WAY TO A TEMPORARY BREAK UP OF CLOUDS THIS AFTERNOON. THEN COLDER
AIR WILL EVENTUALLY RESULT IN BKN TO OVC SKIES DEVELOPING BY FRIDAY.
NO PRECIP IS FORECAST FOR TODAY...WITH HIGH TEMPERATURES REMAINING
LIMITED TO THE 50S. HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT WITH
LIGHT WINDS...AND LOW TEMPERATURES WILL DIP WELL BELOW NORMAL FRIDAY
MORNING. MAV GUIDANCE NUMBERS ACROSS THE NORTHERN TIER ARE JUST
ABOVE FREEZING...AND WE MAY SEE A FEW SPOTS HIT THE FREEZING MARK OR
BELOW FRIDAY MORNING...BUT WITH A RECOGNIZED COLD BIAS...WILL STOP
SHORT OF A FREEZE WATCH RIGHT NOW AND JUST GO WITH AN SPS FOR THE
NORTHERN COUNTIES TONIGHT. TEMPS FRIDAY WILL RECOVER INTO THE 60S
WITH LIGHT NORTHEAST TO EAST WINDS. /54/
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE WILL FLATTEN AND BEGIN TO SHIFT EAST FRIDAY
NIGHT/SATURDAY...AS A SHORTWAVE TROUGH HEADS TOWARD THE TENNESSEE
AND OHIO RIVER VALLEYS. WINDS SHOULD BECOME INCREASINGLY EASTERLY
AS THIS OCCURS...AND COULD RESULT IN A GRADUAL INCREASE IN GULF
MOISTURE OVER THE AREA HEADING INTO THE WEEKEND.
WEATHER CONDITIONS HEADING INTO THE WEEKEND SHOULD BE RATHER QUIET
/FOR THE MOST PART/. BOUNDARY LAYER MOISTURE /ALTHOUGH INCREASING/
SHOULD REMAIN RATHER LIMITED FOR THE FIRST HALF OF THE WEEKEND...AS
A BIT OF SHORTWAVE RIDGING MOVES ACROSS THE REGION. A FEW
PERTURBATIONS ARE SHOWN BY THE MODELS IN THE UPPER ATMOSPHERE JUST
TO OUR NORTH...BUT THESE ARE LIKELY REFLECTIONS OF THE SUBTROPICAL
JET. SO DESPITE AN EXPECTED INCREASE IN CLOUD COVER FOR THE
WEEKEND...LITTLE /IF ANY/ RAINFALL IS ANTICIPATED AT LEAST THROUGH
SATURDAY.
A FLY IN THE OINTMENT REMAINS THE DEVELOPMENT OF A COASTAL
TROUGH...WHICH CONTINUES TO BE SHOWN TO VARYING DEGREES BY MOST OF
THE MEDIUM-RANGE MODELS EARLY THIS MORNING. AS WINDS BECOME
SOUTHEASTERLY ACROSS THE REGION SUNDAY MORNING...LOOK FOR LOW-LEVEL
MOISTURE TO DEEPEN AT A RATHER QUICK PACE. IN FACT...PRECIPITABLE
WATER VALUES SHOULD RISE ABOVE 1.4 TO 1.5 INCHES FOR MUCH OF
SUNDAY. AND WITH THE DEPARTURE OF THE SHORTWAVE RIDGE...SOME OF THE
PERTURBED UPPER-LEVEL ENERGY TO OUR NORTH COULD WORK ITS WAY
SOUTHWARD. PLENTY OF ISENTROPIC UPGLIDE AND LOW CONDENSATION
PRESSURE DEFICITS ON THE 305K THETA SURFACE SHOULD ALSO BE AVAILABLE.
DISPENSING WITH THE WEATHER SPEAK...ALL OF THIS WILL LIKELY LEAD TO
THE POSSIBILITY OF SOME LIGHT RAIN FOR SUNDAY. RIGHT NOW...I THINK
THE GREATEST ODDS OF SEEING RAIN WILL LIKELY OCCUR EASTWARD OF THE
MIDDLE VALLEY. AS SUCH...I WILL LIKELY INCREASE THE ODDS OF SEEING
RAIN IN THESE REGIONS FOR SUNDAY. JUST A SIDE NOTE -- PROBABILITIES
IN THE NUMERICAL GUIDANCE PROBABILITIES HAVE REMAINED IN A NEARLY
STEADY-STATE MODE OVER THE PAST 4 OR 5 MODEL CYCLES. WHILE NOT THE
ONLY JUSTIFICATION FOR INCREASING RAIN PROBABILITIES...THIS DOES
INCREASE MY CONFIDENCE THAT SOMEONE WILL SEE MEASURABLE RAINFALL
ACROSS THIS REGION.
WHAT APPEARS TO BE OUR BEST OPPORTUNITY TO SEE SOME RAIN THIS
WEEKEND WILL BE RATHER SHORT-LIVED...AS MOST OF THE SYNOPTIC SCALE
FORCING SHOULD EXIT THE AREA BY MONDAY. WE WILL THEN START WATCHING
THE PROGRESSION OF AN UPPER LOW...WHICH SHOULD MOVE ONSHORE THE
SOCAL/BAJA CALIFORNIA COAST SUNDAY NIGHT. IT NOW LOOKS LIKE THIS
FEATURE SHOULD WEAKEN TO AN OPEN WAVE AS IT HEADS ACROSS THE DESERT
SOUTHWEST...AND WILL PROBABLY DO A BIT OF PHASING WITH ANOTHER
UPPER-LEVEL SYSTEM MOVING THROUGH THE NORTHERN ROCKIES.
THE EASTWARD MOVEMENT OF THIS SYSTEM SHOULD ALLOW A COLD FRONT TO
MOVE SOUTHWARD ACROSS MID-AMERICA EARLY IN THE WEEK. IT LOOKS LIKE
THE FRONT SHOULD MOVE INTO NORTH TEXAS LATE MONDAY NIGHT/TUESDAY
MORNING...THEN ACROSS OUR CORNER OF THE WORLD SOMETIME TUESDAY
NIGHT. TIMING OF THIS SYSTEM PRESENTED BY AVAILABLE MEDIUM-RANGE
GUIDANCE IS DEBATABLE. MOST MODELS PUSH THE FRONT SOUTH OF THE RIO
GRANDE BY WEDNESDAY MORNING. MEANWHILE...GUIDANCE FROM THE
HYDROMETEOROLOGICAL PREDICTION CENTER LAGS BEHIND THE OPERATIONAL
MODELS SOME 6 TO 12 HOURS. STAY TUNED.
FOR NOW...IT DOES NOT LOOK LIKE WE WILL SEE MUCH IN THE WAY OF
PRECIPITATION WITH THIS SYSTEM. WITH LOW-LEVEL MOISTURE SOMEWHAT
LIMITED...I WILL KEEP RAIN PROBABILITIES AT OR BELOW 14 PERCENT WITH
THIS FORECAST PACKAGE.
HIGHS WILL LIKELY WARM INTO THE 70S BY THIS WEEKEND...BUT MAY FALL
INTO THE 60S BY WEDNESDAY DEPENDING ON THE TIMING OF THE FRONT.
LOWS WILL LIKELY GO ABOVE NORMAL IN MOST PLACES GIVEN THE EXPECTED
CLOUD COVER DURING MOST PERIODS THROUGH NEXT WEDNESDAY. /53/
MARINE...
TODAY THROUGH FRIDAY...A COLD FRONT AND STRONG MARITIME POLAR HIGH
PRESSURE WILL SET UP GALE FORCE GUSTS THIS MORNING THROUGH LATE THIS
AFTERNOON ON THE GULF...WHILE SMALL CRAFT ADVISORY CONDITIONS WILL
EXIST ON THE LAGUNA MADRE. WAVE HEIGHTS WILL LIKELY BUILD TO 12 FEET
OFFSHORE. SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY CONTINUE ON
THE GULF TONIGHT BUT CONDITIONS WILL IMPROVE FRIDAY AS HIGH PRESSURE
SPREADS OUT AND SETTLES OVER THE AREA. /54/
FRIDAY NIGHT THROUGH MONDAY...NORTHEAST TO EAST WINDS SHOULD BECOME
SOUTHEAST ACROSS THE MARINE AREA BY SUNDAY AS SURFACE HIGH PRESSURE
SHIFTS EAST. WINDS AND SEAS SHOULD REMAIN BELOW EXERCISE CAUTION OR
ADVISORY CRITERIA THROUGH MOST OF THE WEEKEND. WIND SPEEDS IN WAKE
OF A COASTAL TROUGH MAY INCREASE A BIT FOR SUNDAY NIGHT AND
MONDAY...AND COULD RESULT IN THE POSTING OF SMALL CRAFT EXERCISE
CAUTIONS OR SMALL CRAFT ADVISORIES BY THIS TIME. /53/
FIRE WEATHER...
NORTH WINDS AT 20 FEET WILL PEAK AT AROUND NOON TODAY BETWEEN 15 AND
20 MPH WITH GUSTS TO 25 MPH FOR THE INLAND AREAS...BUT THE DRIEST
AIR WILL NOT BECOME ESTABLISHED UNTIL MID AFTERNOON...JUST WHEN 20
FOOT WINDS BEGIN DECREASING. THE RELEVANT WEATHER ELEMENTS WILL THUS
BE SLIGHTLY OUT OF PHASE. MEETING THE CRITERIA FOR A RED FLAG
WARNING WILL BE MARGINAL INLAND...BUT WILL BE JUSTIFIABLE NEAR THE
COAST WHERE STRONGER WINDS OF NEAR 25 MPH AT 20 FEET WILL PREVAIL.
AS MENTIONED EARLIER...FIRE DANGER CRITERIA WILL BE MET FOR THE REST
OF THE CWA INLAND FOR SEVERAL HOURS FROM ABOUT 9 AM TO 3 PM CST
TODAY. ZAPATA COUNTY WILL BE MOST MARGINAL FOR THE FIRE DANGER
STATEMENT...WITH FORECAST RELATIVE HUMIDITY VALUES BARELY DECREASING
TO 25 PERCENT...BUT FELT IT WAS CLOSE ENOUGH TO INCLUDE. /54/
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...RED FLAG WARNING UNTIL 4 PM CST THIS AFTERNOON FOR TXZ249>257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CST THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST FRIDAY
FOR GMZ150-155-170-175.
GALE WARNING UNTIL 3 PM CST THIS AFTERNOON FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/58
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1114 AM CST THU JAN 12 2012
.UPDATE...
SNOW FINALLY SPREAD INTO MILWAUKEE AT 1015 THIS MORNING...BUT IT WAS
NOT FROM THE SYSTEM SNOW SPREADING EASTWARD. IT WAS FROM A SNOW BAND
SITTING OVER THE LAKE THAT PIVOTED WESTWARD INTO MILWAUKEE. IT IS
STILL NOT SNOWING IN KENOSHA. WITH THE LOW LEVELS ALREADY SATURATED
DUE TO THE COLD AIR ADVECTION...AND THE UPPER LEVELS SATURATED AS
WELL...THE MID LEVELS NEAR THE LAKE ARE VERY SLOWLY BECOMING
SATURATED. ANY DRIZZLE OR DRY WEATHER WILL BECOME SNOW AT KENOSHA
AIRPORT WITHIN THE NEXT HALF HOUR.
FRONTOGENETIC BANDS ARE EXPECTED TO DEVELOP RAPIDLY EARLY THIS
AFTERNOON ACROSS NORTHERN IL. AT THIS TIME...MODELS SHOW THIS AREA
REMAINING JUST SOUTH OF THE WI/IL BORDER...STALLING IN AN EAST-WEST
ORIENTATION. BUT THERE IS A POSSIBILITY THAT THEY COULD DRIFT INTO
SOUTHERN WI AS THE SYSTEM PIVOTS AROUND THE UPPER LOW. THE OTHER
CONCERN WILL BE WATCHING FOR LAKE EFFECT/ENHANCEMENT NEAR THE
LAKESHORE COUNTIES. THE RUC IS SHOWING A PERIOD OF NNE 1000-900MB
WINDS AND CONVERGENCE ALONG THE LAKESHORE BETWEEN 18Z TO 21Z FROM
SHEBOYGAN SOUTH THROUGH NORTHEAST IL...THOUGH THE STRONGEST
CONVERGENCE REMAINS JUST OFFSHORE. THE RUC SHOWS A FOCUSED MAX
CONVERGENCE OVER FAR SOUTHEAST WI AROUND 00Z THAT DROPS SOUTH OUT OF
THE STATE BY 03Z. THE HRRR KEEPS THE CONVERGENCE AND HIGHER PRECIP
AMOUNTS OFFSHORE WITH A MORE NNW WIND FLOW.
WILL NEED TO KEEP MONITORING THE SHORT-TERM MODELS FOR HEADLINE
CONCERNS AND KEEP STRESSING THE POOR WEATHER DURING THE AFTERNOON
COMMUTE.
&&
.AVIATION/18Z TAFS/...
EXPECT IFR/LIFR LEVELS ACROSS THE AREA THROUGH THE AFTERNOON.
CONDITIONS SHOULD BEGIN TO LIFT TO MVFR LEVELS LATER THIS EVENING
AND OVERNIGHT AS THE SNOW BEGINS TO WIND DOWN.
BY 6 PM THE KMSN AREA SHOULD HAVE AROUND 3.5 TO 4 INCHES ON THE
GROUND WITH THE PEAK OF THE SNOW OCCURRING AROUND 18-20Z. ANOTHER
INCH SHOULD OCCUR AFTER 00Z FRIDAY. AT KMKE...ABOUT 3 INCHES SHOULD
BE REALIZED BY 00Z THIS EVENING WITH ANOTHER 2 INCHES BEFORE
MIDNIGHT. THE PEAK OF THE SNOW IN MILWAUKEE WILL CLOSER TO 23-01Z.
LOOK FOR NORTHWEST WINDS OF 15 TO 25 MPH WITH A FEW GUSTS TO 30 MPH
THROUGH THE EVENT.
LAKE ENHANCED SNOW MAY CAUSE SLIGHTLY HIGHER SNOWFALL RATES AT TIMES
AT MKE AND ENW. A BAND OF SNOW EXPECTED TO LINE UP EAST TO WEST
ACROSS FAR NORTHERN IL HAS THE POSSIBILITY OF DRIFTING NORTHWARD
INTO WALWORTH AND KENOSHA COUNTIES THIS AFTERNOON AND NEEDS TO BE
MONITORED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 4 AM CST FRIDAY FOR WIZ046-047-056-
057-062-063-067>069.
WINTER WEATHER ADVISORY UNTIL 9 AM CST FRIDAY FOR WIZ051-052-
058>060-064>066-070>072.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST FRIDAY NIGHT FOR
LMZ643>646.
&&
$$
UPDATE...MRC