FXUS61 KPBZ 151130
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
630 AM EST TUE DEC 15 2009
.SYNOPSIS...
LOW PRESSURE OVER LAKE ONTARIO WILL MOVE TO NEW ENGLAND TODAY WITH
MUCH COLDER AIR MOVING INTO THE REGION FOR THE REMAINDER OF THE
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT IS NOW EAST OF THE RIDGES WITH MUCH COLDER AIR NOW
ACROSS OHIO QUICKLY MOVING EAST. LOW CHANCE POPS TODAY INTO
TONIGHT EXCEPT FOR RIDGES AND AREAS NORTH OF I-80 WITH COLD
ADVECTION ACROSS LAKES. LAKE ENHANCED UPSLOPE WILL BE TEMPERED BY
QUITE DRY AIR, LOW INVERSION, AND SURFACE HIGH QUICKLY MOVING MOVING TO THE
LOWER OHIO VALLY BY WEDNESDAY MORNING. SNOW SHOWERS STILL EXPECTED
TO GIVE AN INCH OR SO TO RIDGES AND NORTHERN TIER COUNTIES WITH
LITTLE ACCUMULATION ELSEWHERE THIS AFTERNOON AND TONIGHT.
TEMPERATURES WILL BE FALLING THROUGH THE DAY WITH HIGH
TEMPERATURES FOR THE DAY ALREADY HAVEN BEEN REACHED IN MOST
LOCATIONS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL DOMINATE THE WEATHER FOR WEDNESDAY AND THURSDAY
WITH ONLY A FEW SNOW SHOWERS RIDGES AND NORTH. LOW CHANCE POPS IN
THE GRIDS FRIDAY AS SHORTWAVE TROF COMES UNDERNEATH CLOSED LOW
NORTH OF MAINE FOR FRIDAY. MODELS HAVING A BIT OF TROUBLE WITH
HIGH LATITUDE BLOCKING PATTERN AND CONFIDENCE IS NOT GREAT IN
FORECAST BY FRIDAY. THE ONLY CONFIDENT PART OF THE FORECAST IS
BELOW NORMAL TEMPERATURES ON AVERAGE THROUGH FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
ONLY CHANGE TO EXTENDED WAS TO NUDGE TEMPERATURES DOWN A NOTCH AS
COLD VORTEX LOOKS TO BE IN CONTROL THROUGH PERIOD. TIMING OF
SIGNIFICANT PRECIP EVENTS, IF ANY, WILL BE A STRUGGLE AND NO
MAJOR CHANGES MADE TO GRIDS FROM PREVIOUS HPC DRIVEN FORECAST.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT WILL ADVECT EAST OF THE TERMINALS TODAY WITH A FEW LIGHT
RAIN SHOWERS POSSIBLE WITH ITS PASSAGE. BEHIND THE COLD FRONT...CEILINGS
MAY DROP TO NEAR IFR...SLOWLY RISING BACK TO AROUND 2KFT IN THE
AFTERNOON. WINDS WILL BE WESTERLY AND GUST TO 20KTS AT TIMES. WITH
A NORTHWESTERLY FLOW ALOFT AND COLD AIR ADVECTION...SOME LAKE
EFFECT SNOW SHOWERS WILL BE POSSIBLE THIS AFTERNOON...WITH THE
BEST CHANCE OF SNOW SHOWERS WITH REDUCED VISIBILITIES NORTH OF
KPIT. SNOW SHOWERS WILL BEGIN TO DIMINISH AROUND 00Z...EXCEPT AT
KFKL/KDUJ WHERE LOW-LEVEL MOISTURE WILL ALLOW FOR SHOWERS TO
CONTINUE OVERNIGHT.
MVFR CEILINGS TUESDAY NIGHT WILL BECOME VFR AND CLOUD COVERAGE
WILL BEGIN TO DIMINISH WEDNESDAY MORNING AS LOW-LEVEL MOISTURE
ADVECTS NORTHEAST OF THE AREA AND HIGH PRESSURE BUILDS IN FROM THE
WEST. HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE AREA LATE THIS
WEEK WITH MOSTLY VFR CONDITIONS EXPECTED THROUGH SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
