FXUS61 KPBZ 302054
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
354 PM EST MON NOV 30 2009
.SYNOPSIS...
COLDER NORTHWEST FLOW WILL BRING A FEW SNOW SHOWERS TONIGHT INTO
EARLY TUESDAY. HIGH PRESSURE WILL BRING DRY CONDITIONS LATER
TUESDAY AND TUESDAY NIGHT. A DEEPENING LOW PRESSURE SYSTEM MOVING
NORTH FROM THE GULF STATES WILL BRING RAIN WEDNESDAY AND WEDNESDAY
NIGHT CHANGING TO SNOW SHOWERS LATER THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
UPPER TROF MOVES EAST THROUGH REGION TONIGHT WITH COLD ADVECTION
IN NORTHWEST FLOW BRINGING SCATTERED SNOW SHOWERS. ONLY LIGHT
ACCUMULATION EXPECTED AS MOISTURE IS LIMITED AND 850MB TEMPS
SPREAD TO LAKE BARELY ENOUGH TO PRODUCE NOTICEABLE LAKE EFFECT.
LEFTOVER SNOW SHOWERS EARLY TUESDAY THEN SURFACE RIDGE CLEANS
REGION OUT LATER IN THE DAY. TEMPERATURES NEAR MOS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
MODELS HAVE COME INTO BETTER AGREEMENT OVERALL WITH SOUTHERN
STREAM CLOSED LOW OPENING AND QUICKLY MOVING NORTHEAST WEDNESDAY
AND WEDNESDAY NIGHT WITH SURFACE LOW MOVING QUICKLY TO OHIO VALLEY
BY THURSDAY MORNING AND THEN TO NEW YORK STATE BY LATE DAY. RAIN
WILL OVERSPREAD THE REGION WEDNESDAY AND CONTINUE INTO WEDNESDAY
NIGHT. DRY SLOT WILL THEN WORK INTO REGION THURSDAY MORNING AS
SURFACE LOW HEADS NORTH AND COLDER AIR WRAPS IN BEHIND SYSTEM
CHANGING PRECIP TO SNOW SHOWERS BY EVENING. MILD AHEAD OF
WEDNESDAY THEN COOLER THURSDAY BEHIND FROPA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
DEEP DIGGING CLOSED LOW WILL MOVE FROM NORTHERN PLAINS TO GREAT
LAKES THROUGH PERIOD BRINGING COLDEST AIR OF SEASON WITH OFF AND
ON SNOW SHOWERS DUE TO LAKE EFFECT AND DISTURBANCES MOVING UNDER
CLOSED LOW. NOT MUCH TO ARGUE WITH FROM HPC PROGS AND FOLLOWED.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
POST FRONTAL AREA OF PRECIPITATION MOVING OUT OF THE MOUNTAINS OF
WEST VIRGINIA AND MD. MVFR TO IFR CEILINGS CAN BE EXPECTED IN THE
THIS AREA OF POST FRONTAL ZONE BUT WILL EXIT THE AREA BY 19Z.
COLD ADVECTION OVER THE AREA AND BREAKS IN THE CLOUD COVER RESULTING
IN SCATTERED LIGHT RAIN OR SNOW SHOWERS...ESPECIALLY IN NORTHERN
AREAS OF PENNSYLVANIA. WEAK SHORT WAVE MOVING THROUGH THIS AREA
FURTHER ENHANCING THE INSTABILITY.
MVFR CEILINGS OVERNIGHT. HIGH PRESSURE BUILDING INTO THE AREA
TUESDAY WITH WINDS TURNING WEST TO SOUTHWEST WITH VFR CONDITIONS.
HIGH PRESSURE WILL CONTINUE VFR CONDITIONS INTO WEDNESDAY. A
STRONG STORM SYSTEM MOVING NORTHEAST FROM THE DEEP SOUTH WILL BRING
RESTRICTIONS IN RAIN THURSDAY WITH SNOW SHOWERS FRIDAY AND SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
