000
FXUS61 KPBZ 032259
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
559 PM EST WED DEC 3 2008
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA LATE TONIGHT AND THURSDAY...BRINGING
RAIN SHOWERS LATE TONIGHT...CHANGING TO SNOW SHOWERS BY THURSDAY
AFTERNOON. MUCH COLDER CONDITIONS AND PERIODS OF SNOW SHOWERS WILL
CONTINUE THURSDAY NIGHT INTO FRIDAY AS LOW PRESSURE GRADUALLY EXITS.
UNSEASONABLY COLD CONDITIONS WILL CONTINUE THROUGH THE WEEKEND...WITH
A CHANCE OF SNOW SHOWERS LATE SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
CLOUDS CONTINUE TO INCREASE THIS EVENING WITH SHOWERS MOVING INTO
NORTHWEST PA FROM OHIO. EXPECT MORE WIDESPREAD PRECIP AFTER
MIDNIGHT SPREADING WEST TO EAST. MOSTLY RAIN AT THE START EXCEPT
FAR NORTH AND RIDGES, THEN MIXING OVER AND CHANGING TO ALL SNOW
THROUGH THURSDAY MORNING AND AFTERNOON AS PRECIP DIMINISHES.
ONLY LIGHT SNOW ACCUMULATIONS MAINLY RIDGES AND NORTH OF I-80 THURSDAY.
TEMPERATURES IN THE 30S OVERNIGHT THEN STEADY OR FALLING THURSDAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
UPPER LEVEL TROUGHING WILL AFFECT THE AREA INTO THE WEEKEND. MUCH
COLDER AIR WILL WORK INTO THE REGION...WITH HIGHS FRIDAY REMAINING
IN THE 20S...WITH ONLY A LITTLE MODERATION FOR SATURDAY. WITH THE
CENTER OF THE LOW WELL TO THE NORTH...FLOW WILL REMAIN WESTERLY
VERSUS NW...MOISTURE OFF THE LAKES WILL BE SOMEWHAT LIMITED...SO
WILL KEEP SNOW ACCUMULATIONS UNDER ADVISORY LEVELS...WITH 1-3 INCH
ACCUMS ACROSS THE NORTH/RIDGES THURSDAY NIGHT INTO FRIDAY. A BRIEF
BREAK FROM PRECIP IS EXPECTED UNDER FLAT RIDGING FOR FRIDAY INTO
SATURDAY...BEFORE ANOTHER WAVE WILL APPROACH THE AREA BY LATE
SATURDAY BRINGING A CHANCE OF SNOW SHOWERS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A LOW PRESSURE SYSTEM WILL PUSH EASTWARD INTO NEW ENGLAND SUNDAY.
SNOW SHOWERS EXPECTED TO TAPER OFF MOST AREAS BY SUNDAY NIGHT. COLD
AIR WILL REMAIN OVER THE REGION THROUGH MONDAY...WITH DRY CONDITIONS
UNDER SURFACE HIGH PRESSURE.
NEXT SYSTEM WILL APPROACH FROM THE WEST BY MONDAY NIGHT AND MAKE
SLOW EASTWARD PROGRESS THROUGH THE MIDDLE OF THE WEEK. SCATTERED
RAIN AND SNOW SHOWERS ARE FORECAST MONDAY INTO TUESDAY. NEW MODEL
RUNS NOW TRYING TO FORM A COASTAL LOW LATER TUESDAY INTO WEDNESDAY
TOWARD THE CAROLINAS POSSIBLY MOVING UP THE MID ATLANTIC COAST.
EDGED UP SNOW CHANCE FOR WEDNESDAY WITH UNCERTAIN FORECAST.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL HOLD THROUGH EARLY TONIGHT AS SURFACE RIDGE
MOVES OFF THE ATLANTIC COAST. SOUTHWEST WINDS SHOULD GUST TO 20
TO 25 KT AHEAD OF FRONT OVERNIGHT ESPECIALLY AS FRONT GETS CLOSER
AND 850MB WINDS MIX DOWN. APPROACHING COLD FRONT WILL SPREAD
SHOWERS EASTWARD ACROSS THE REGION BY LATE TONIGHT WITH CONDITIONS
LOWERING TO MVFR.
COLDER AIR WILL PUSH IN BEHIND THE SYSTEM THURSDAY MORNING WITH
PRECIPITATION CHANGING OVER TO SNOW SHOWERS. MVFR STRATOCUMULUS WILL
HOLD THROUGH THE DAY WITH CONDITIONS OCCASIONALLY LOWERING TO IFR IN
SNOW SHOWERS.
IMPROVEMENT TO GENERALLY VFR WEATHER IS EXPECTED BY FRIDAY UNDER
WEAK HIGH PRESSURE.
RESTRICTIONS ARE AGAIN POSSIBLE BY LATE SATURDAY AND SUNDAY AS
ANOTHER LOW PRESSURE SYSTEM CROSSES THE GREAT LAKES REGION.
HIGH PRESSURE IS EXPECTED TO RETURN FOR SUNDAY NIGHT AND MONDAY
BRINGING UNRESTRICTED CONDITIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
