FXUS61 KPBZ 091957
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
257 PM EST WED DEC 9 2009
.SYNOPSIS...
A STRONG COLD FRONT WILL EXIT THE AREA THIS EVENING. SCATTERED
TO NUMEROUS SHOWERS WILL GRADUALLY DIMINISH...WITH MUCH COLDER
AIR WORKING INTO THE REGION. STRONG WINDS WILL CONTINUE BEHIND
THE FRONT THROUGH TONIGHT...WITH WINDY CONDITIONS PERSISTING
THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A COLD FRONT IS ENTERING WESTERN PA...WITH A BAND OF SHOWERS AND
THUNDERSTORMS ALONG/JUST AHEAD OF THE BOUNDARY. STRONG TO SEVERE
THUNDERSTORMS HAVE DIMINISHED IN INTENSITY AND ARE EXITING INTO
CENTRAL PA...SO WILL NOT INCLUDE TSTM WORDING FOR THIS EVENING.
WILL CONTINUE THE HIGH WIND WARNING THROUGH THIS EVENING FOR THE
LOWLANDS OF OH/WV/PA...AND FOR THE EASTERN UPLANDS THROUGH THE
OVERNIGHT. PRECIP WILL CHANGE TO SNOW SHOWERS THIS EVENING...WITH
UPSLOPE AND LAKE ENHANCED SNOW SHOWERS LIKELY. WITH THE FLOW
W/SW...ACCUMS WILL REMAIN MINOR...AND LIMITED THE MAINLY THE
RIDGES AND ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
SCATTERED UPSLOPE/LAKE ENHANCED SNOW SHOWERS WILL CONTINUE FOR
THE NORTH/RIDGES. WINDS WILL GRADUALLY DECREASE...BUT REMAIN
15-20 MPH WITH GUSTS TO 30 MPH OR SO THROUGH THURSDAY. ANOTHER
CONCERN WILL BE LOW WIND CHILL VALUES THURSDAY NIGHT/EARLY FRIDAY.
GIVEN WINDS OF 10-20 MPH AND TEMPERATURES OF 10-15 ABOVE ZERO...WIND
CHILL VALUES WILL RANGE FROM ZERO TO 5 BELOW FOR THE LOWLANDS...AND
-5 TO -10 FOR THE HIGHER ELEVATIONS. THUS...WILL NOT ISSUE A WIND
CHILL ADVISORY FOR NOW. LOW AMPLITUDE RIDGING ALOFT WILL RESULT
IN MAINLY DRY CONDITIONS FOR FRIDAY/SATURDAY WITH LESS WIND...ALTHOUGH
TEMPERATURES WILL REMAIN SIGNIFICANTLY BELOW NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE WILL SLIDE EAST OF THE REGION SATURDAY NIGHT.
A WEAK SYSTEM PASSING TO OUR SOUTH WILL THEN BRING AN INCREASE IN
MOISTURE AND A SMALL CHANCE OF RAIN AND SNOW SHOWERS SATURDAY NIGHT
AND SUNDAY.
THE NEXT COLD FRONT APPROACHING FROM THE WEST WILL BRING SCATTERED
POPS FOR SNOW SHOWERS AND SNOW SHOWERS MIXED WITH RAIN SOUTH MONDAY
NIGHT AND TUESDAY.
SURFACE RIDGE WILL BUILD BACK INTO THE REGION WEDNESDAY WITH MAINLY
DRY CONDITIONS EXPECTED.
TEMPERATURES ARE EXPECTED TO BE WITHIN A FEW DEGREES OF NORMAL FOR
THE EXTENDED PERIOD.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
COLD FRONT WILL CROSS WESTERN PA DURING THE NEXT FEW HOURS WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS REDUCING CONDITIONS TO
MVFR. BRIEF IFR CONDITIONS ARE STILL POSSIBLE IN HEAVIER SHOWERS.
STRONG PRESSURE GRADIENT WILL CONTINUE TO GENERATE SOUTHWEST TO WEST
SURFACE WINDS 20 TO 30 KT WITH OCCASIONAL GUSTS OVER 40 KT THROUGH
TONIGHT AND GRADUALLY DIMINISHING DURING THURSDAY.
BROKEN VFR CEILINGS SHOULD PREVAIL TONIGHT AND THURSDAY AT MOST
TERMINAL SITES...WITH MVFR CEILINGS AND OCCASIONAL VISIBILITY
RESTRICTIONS IN SCATTERED SNOW SHOWERS AT FAR NORTHERN TERMINALS AND
ALONG THE RIDGES.
GENERALLY VFR CONDITIONS CAN BE EXPECTED AS HIGH PRESSURE BUILDS IN
FRIDAY AND MOVES EAST ACROSS THE REGION THROUGH SATURDAY NIGHT. A
WEAK SYSTEM PASSING TO OUR SOUTH WILL THEN BRING AN INCREASE IN
MOISTURE AND SCATTERED RAIN AND SNOW SHOWERS SATURDAY NIGHT AND
SUNDAY WITH THE POTENTIAL FOR MVFR/IFR RESTRICTIONS.
VFR CONDITIONS SHOULD PREVAIL MONDAY UNDER WEAK RIDGING.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...HIGH WIND WARNING UNTIL 6 AM EST THURSDAY FOR MDZ001.
OH...HIGH WIND WARNING UNTIL MIDNIGHT EST TONIGHT FOR OHZ039>041-
048>050-057>059-068-069.
PA...HIGH WIND WARNING UNTIL MIDNIGHT EST TONIGHT FOR PAZ007-008-
013-014-020-021-029-031.
HIGH WIND WARNING UNTIL 6 AM EST THURSDAY FOR PAZ009-015-016-
022-023-030-032.
WV...HIGH WIND WARNING UNTIL MIDNIGHT EST TONIGHT FOR WVZ001>004-
012-021-022.
HIGH WIND WARNING UNTIL 6 AM EST THURSDAY FOR WVZ023-041.
&&
$$
