210
FXUS61 KPBZ 081849
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
149 PM EST THU DEC 8 2022
SYNOPSIS
CLOUDY CONDITIONS WILL PREVAIL TODAY; A WEAK DISTURBANCE COULD
RESULT IN LIGHT PRECIPITATION SOUTH OF I-70 THIS EVENING. PERIODIC
PRECIPITATION CHANCES, INCLUDING A WINTRY MIX FOR PORTIONS OF
THE REGION, INCREASE LATE FRIDAY INTO SATURDAY.
NEAR TERM /THROUGH TONIGHT/
HIGH PRESSURE OVER THE GREAT LAKES IS EXPECTED TO ADVANCE DRIER
AIR FROM THE NORTH INTO THE REGION TODAY. A HEAVY CLOUD DECK
WILL REMAIN WITH COLD AIR ALOFT, CONDENSING WHATEVER WATER
VAPOR WE HAVE AVAILABLE WITHIN THE BOUNDARY LAYER.
A CROSSING SHORTWAVE MAY BRING LIGHT RAIN CHANCES FOR AREAS
SOUTH OF INTERSTATE 70 LATER THIS AFTERNOON. THE NBM 95TH
PERCENTILE IS RANGING ON PRECIP AMOUNTS TO BE BETWEEN A TRACE TO
0.20 INCHES IN THE RIDGES OF WEST VIRGINIA THROUGH MIDNIGHT.
HIGH TEMPERATURES ARE EXPECTED TO BE AROUND 5 DEGREES ABOVE
SEASONABLE LEVELS.
SHORT TERM /FRIDAY THROUGH SUNDAY/
HIGH PRESSURE CENTERED OVER ERN CANADA IS PROGGED TO RIDGE
FURTHER ACROSS THE UPPER OHIO VALLEY REGION FRIDAY, WITH MAINLY
DRY WEATHER EXPECTED TO START THE DAY. THE RIDGE SHOULD SHIFT
EWD THROUGH THE DAY, AS A SHORTWAVE TROUGH AND ASSOCIATED
WEAKENING SFC LOW APPROACHES THE REGION FROM THE UPPER MIDWEST.
RAIN CHANCES COULD INCREASE FRIDAY NIGHT WITH THE CROSSING
SHORTWAVE. HOWEVER, THE NBM OVER THE LAST 12 TO 24 HOURS HAS
BEEN TRENDING DOWN ON PRECIP CHANCES/OVERALL QPF DUE TO THE
INFLUENCE OF THE RIDGE. IF PRECIP DOES OCCUR, IT WILL LIKELY BE
LIGHT. NOTE, AREAS ALONG THE HIGHEST TERRAIN OF THE LAUREL
HIGHLAND AND WV COULD SEE A BRIEF PERIOD OF LIGHT FREEZING RAIN
WITH COLDER TEMPERATURES IN UPSLOPING ERLY FLOW IF PRECIP DOES
FORM.
ANY ONGOING PRECIP SHOULD END SATURDAY MORNING AS THE SHORTWAVE
EXITS THE REGION, AND FLAT RIDGING BRIEFLY BUILDS ACROSS THE
UPPER OH VALLEY REGION AHEAD OF THE NEXT MIDWESTERN SHORTWAVE.
TEMPERATURES FOR BOTH FRIDAY/SATURDAY SHOULD REMAIN SEASONABLE
OR SLIGHTLY ABOVE AVERAGE WITH A BUILDING RIDGE.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/
LONG TERM MODEL GUIDANCE PROJECT A SHORTWAVE TROUGH, AND ITS
ASSOCIATED COLD FRONT, QUICKLY EXITS THE REGION SUNDAY NIGHT
INTO MONDAY. MODELS HAVE BEEN CONSISTENT OVER THE LAST FEW RUNS ON
LAKE ENHANCED FOLLOWED BY LAKE EFFECT SNOW IN THE WAKE OF THE
FRONT EARLY NEXT WEEK.
PROLONG RIDGING TUESDAY THROUGH EARLY WEDNESDAY WILL KEEP THE
REGION DRY, GRADUALLY WARM IS ANTICIPATED THROUGH THIS PERIOD AS
WINDS SHIFT FROM EAST TO SOUTHWEST.
OVER THE LAST 24HRS THE NBM HAS DELAYED THE TIMING OF
PRECIPITATION, ASSOCIATED WITH A ROBUST (BUT SLOW MOVING) LOW
PRESSURE SYSTEM DEVELOPING ACROSS THE PLAINS. WITH THIS LATEST
FORECAST UPDATE, HIGHER PRECIP CHANCES ARE CURRENTLY TIMED TO
START AFTER DAWN WEDNESDAY. WITH COLD/DRY AIR, FROM LINGERING
HIGH PRESSURE INSTILLED ACROSS THE REGION, PRECIP TYPE MAY START
AS A WINTRY MIX FOR A PERIOD OF TIME BEFORE SWITCHING OVER TO
RAIN UNDER WARM ADVECTION. HOWEVER, NOTE THAT CONFIDENCE IS NOT
VERY HIGH DURING THE WEDNESDAY TIME PERIOD. SOME ENSEMBLE MODELS
ARE EVEN DELAYING AN INCREASE IN PRECIP CHANCES UNTIL THURSDAY.
AVIATION /17Z THURSDAY THROUGH MONDAY/
CIGS GENERALLY IN THE MVFR RANGE CONTINUE ACROSS AREA TERMINALS.
SOME SLIGHT IMPROVEMENT HAS BEEN OBSERVED SINCE DAWN WITH MIXING
AND DRIER AIR NEAR THE SURFACE, BUT OTHERWISE MOISTURE REMAINS
TRAPPED UNDERNEATH A STOUT INVERSION AROUND 850MB, OR ABOUT
3000FT AGL.
IMPROVEMENT TO VFR IS EXPECTED LATER THIS AFTERNOON AND EVENING
AS DRY ADVECTION AND MIXING INCREASES BEHIND THE REINFORCING
FRONT, AND AS SFC HIGH PRESSURE BEGINS TO BUILD IN. MVFR CIGS
ARE POSSIBLE AGAIN LATE TONIGHT FOR FKL AND DUJ AS THE LOWER
LEVELS BECOME SATURATED.
OUTLOOK.
VFR EXPECTED FRIDAY BEFORE RESTRICTION POTENTIAL RETURNS WITH
RAIN FRIDAY NIGHT, AND AGAIN SATURDAY NIGHT AND SUNDAY. VFR
RETURNS MONDAY UNDER HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...HEFFERAN
NEAR TERM...HEFFERAN
SHORT TERM...HWOPBZ/07 LONG TERM...HEFFERAN AVIATION...BROWN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page