863
FXUS61 KPBZ 291752
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
152 PM EDT THU MAY 29 2025
SYNOPSIS
RELATIVELY QUIET WEATHER IS EXPECTED TODAY WITH READINGS WARMING
TO NEAR NORMAL. LOW PRESSURE TRACKING ACROSS WEST VIRGINIA WILL
BRING SHOWERS FRIDAY ESPECIALLY FROM PITTSBURGH AREA ON SOUTH.
SHOWERS WILL LINGER FRIDAY NIGHT AND SATURDAY AS ANOTHER LOW
PRESSURE AREA DROPS OUT OF THE GREAT LAKES. COOL AND BLUSTERY
WEATHER IS EXPECTED SATURDAY AND READINGS WILL BE ABOUT 10
DEGREES BELOW NORMAL.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- RAIN CHANCES INCREASE SLIGHTLY IN THE AFTERNOON/OVERNIGHT.
- TEMPERATURES AROUND NORMAL.
-------------------------------------------------------------------
A LOW LEVEL SHORTWAVE RIDING UP THE PREVAILING WESTERLY MID-
LEVEL FLOW WILL ALLOW SOME MEAGER FORCING FOR SHOWER AND
SCATTERED STORM DEVELOPMENT THIS AFTERNOON, THOUGH INTENSE
UPDRAFT DEVELOPMENT SEEMS VERY LOW PROBABILITY WITH AMPLE DRY
AIR IN THE 700MB TO 500MB LAYER AS EVIDENCED BY THE 12Z
SOUNDING. WHILE MOST RAIN WILL BE WARM RAIN, IT IS EXPECTED TO
BE QUITE SHALLOW AND BELOW THIS LAYER. HREF MAXIMUM RAINFALL
RATES ARE AROUND 0.25"/HR AND CONFINED TO ISOLATED, FAIRLY
PROGRESSIVE CELLS. THIS WILL CONTINUE A LOW FLOODING THREAT
LATER TODAY AND TONIGHT AS THIS WAVE MOVES THROUGH.
MID-LEVEL FLOW ACCELERATES OVERNIGHT AHEAD OF THE NEXT WAVE,
BUT THE BEST FORCING DOES NOT ARRIVE UNTIL AFTER SUNRISE. MOSTLY
BROKEN CLOUD DECKS WILL PREVAIL WITH TEMPERATURES RIGHT AROUND
SEASONAL NORMALS.
SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/
KEY MESSAGES:
- WIDESPREAD RAINFALL RETURNS FRIDAY ESPECIALLY PITTSBURGH ON
SOUTH
----------------------------------------------------------------
UPPER TROUGH DIVING SOUTH OUT OF ONTARIO WILL PHASE WITH OHIO
VALLEY TROUGH AND ALLOW IT TO DEEPEN AS IT HEADS EAST. THE
RESULT IS 90-120 METER HEIGHT FALLS ALONG THE MASON-DIXON LINE
ON FRIDAY.
LOW PRESSURE SHOULD DEEPEN AS IT MOVES ACROSS EASTERN KENTUCKY
AND WEST VIRGINIA IN THE MORNING AND HEADS FOR THE CHESAPEAKE
BAY IN THE EVENING. BY THE TIME THE LOW REACHES SOUTHERN NEW
ENGLAND LATE FRIDAY, IT WILL HAVE DROPPED ABOUT 20 MB IN 24
HOURS WHICH IS QUITE IMPRESSIVE FOR THE END OF MAY.
CONFIDENCE IN A SWATH OF RAIN PRODUCING 0.25-0.50" IS
RELATIVELY HIGH FROM ZANESVILLE TO PITTSBURGH TO INDIANA ON
SOUTH. DOWN IN PRESTON AND TUCKER COUNTIES WV, RAINFALL OF
0.50-1.00" IS LIKELY WITH NBM 90TH PERCENTILE PQPF24 PRODUCING
ABOUT 1.75". WPC HAS INTRODUCED A SLIGHT RISK OF EXCESSIVE RAIN
TO TUCKER COUNTY AS A RESULT, GIVEN THE RECENT 2.00-2.50" OF
RAINFALL.
DESPITE THE PRIMARY TROUGH PUSHING EAST TONIGHT AND ENDING UP
AROUND NEW YORK CITY, THE TROUGH DIGGING OUT OF ONTARIO INTO THE
GREAT LAKES SHOULD ARRIVE OVER FORECAST AREA LATE FRIDAY TONIGHT,
WITH HEIGHTS CONTINUING TO FALL ANOTHER 60 METERS TO NEAR 5500
AT 500 MB. THIS TROUGH SHOULD BRING ANOTHER ROUND OF SHOWERS
AFTER MIDNIGHT TO MOST OF THE FORECAST AREA.
LONG TERM /SATURDAY THROUGH THURSDAY/
KEY MESSAGES:
- COOL AND BLUSTERY DAY ON SATURDAY WITH READINGS ABOUT 10F
BELOW NORMAL
- WARMING TEMPERATURES BEGIN SUNDAY AND CONTINUE THROUGH MIDWEEK
-------------------------------------------------------------------
850 MB TEMPS ARE FORECAST TO FALL FROM ABOUT +8C SATURDAY
MORNING TO ABOUT 2-3C SATURDAY EVENING. COOL NORTHWEST FLOW
WITH RATHER SIGNIFICANT LOW LEVEL COLD AIR ADVECTION EXPECTED TO
DAMPEN THE DIURNAL CYCLE ON SATURDAY WITH TEMPERATURES REACHING
THE LOWER TO MIDDLE 60S BY MIDDAY AND THEN REMAINING STEADY OR
PERHAPS FALLING STARTING IN THE MIDDLE AFTERNOON HOURS.
SHOWERS ASSOCIATED WITH THE TROUGH ARE MOST LIKELY IN THE
MORNING WITH DRYING EXPECTED IN THE AFTERNOON.
SUNDAY HEIGHTS RISE ABOUT 60 METERS BUT ONLY A MODEST REBOUND IN
TEMPERATURES IS EXPECTED WITH MINIMAL WARMING AT 850 MB TO ABOUT
+4C.
60 TO 100 METER HEIGHT RISES ARE EXPECTED MONDAY AS UPPER RIDGE
BUILDS FROM THE MISSISSIPPI RIVER VALLEY INTO THE GREAT LAKES.
850 MB MEAN TEMPS RISE TO +10C SO A DECENT JUMP IN TEMPERATURES
SHOULD PUSH US BACK TO ABOUT NORMAL.
HEIGHTS LIKELY KEEP RISING ANOTHER 40-70 METERS ON TUESDAY AND
THE UPPER RIDGE WILL LIKELY BE OVERHEAD INTO WEDNESDAY. ENSEMBLE
GUIDANCE HAS BEEN PERSISTENT IN BRINGING TEMPERATURES UP TO
ABOUT 10F ABOVE NORMAL BY MIDWEEK. THERE ARE ALWAYS FLIES IN THE
OINTMENT, AS SOME OF THE GUIDANCE DOES DEVELOP A CLOSED LOW
ALONG THE ATLANTIC COAST WHICH COULD LIMIT THE WARMING SOME. BUT
GIVEN THE RECENT COOL PERIOD, THERE IS STILL HIGH CONFIDENCE IN
MUCH WARMER WEATHER THAN THE 58F HIGH AT PITTSBURGH YESTERDAY.
THE LAST 80 DEGREE DAY AT KPIT WAS MAY 16TH, AND THERE IS A GOOD
SHOT OF 80 DEGREES OR MORE TUESDAY AND WEDNESDAY. NBM 25TH-75TH
PERCENTILE MAXT ON WEDNESDAY IS 84-90. SO IT APPEARS THAT JUNE
WILL BRING A TASTE OF SUMMER IF THE ENSEMBLES ARE ON THE MARK.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
FOR ANY SITES YET TO RETURN TO VFR EARLY THIS AFTERNOON, EXPECT
THAT THAT WILL OCCUR BY 18-19Z WITH STRATUS ERODING AND BECOMING
A DIURNALLY DRIVEN CU DECK WITH CLOUD BASES AROUND 5-6KFT.
OCCASIONAL GUSTS UP TO 20 KTS CAN'T BE RULED OUT THIS AFTERNOON,
BUT WIND IS LIKELY TO REMAIN BETWEEN 5-10 KNOTS OUT OF THE
SOUTHWEST BEFORE CALMING OVERNIGHT.
SOME AREAS OF FOG ARE AGAIN POSSIBLE TOWARD DAWN ON FRIDAY
MORNING WITH HIGHEST PROBABILITY AT MGW AND LBE WHERE WIND IS
EXPECTED TO BE LIGHTEST AND CROSSOVER TEMPERATURES ARE MORE
LIKELY TO BE ACHIEVED. CONFIDENCE IS LOWER AT OTHER SITES, BUT
IF OTHERS WERE TO BE AFFECTED, IT WOULD LIKELY BE AGC, HLG, AND
BVI. AT THIS POINT, OPTED NOT TO MENTION VIS RESTRICTIONS AT
THOSE THREE, BUT FURTHER CONSIDERATION MAY BE NEEDED FOR THE
NEXT UPDATE CYCLE.
WIND WILL PICK UP OUT OF THE WEST TO NORTHWEST TOMORROW MORNING
AS MID AND HIGH LEVEL CLOUDS THICKEN AND LOWER AHEAD OF
APPROACHING AFTERNOON RAIN CHANCES. TOP DOWN SATURATION WILL
NEED TO OCCUR BEFORE APPRECIABLE RAIN REACHES THE GROUND AND
RESTRICTIVE CIGS ARRIVE. PROBABILITY FOR RAIN IS HIGHEST FROM
PIT/AGC SOUTH AFTER 17Z OR SO. MVFR RESTRICTIONS ARE LIKELY
WITHIN THE SHOWERS WITH A 70-90% CHANCE, BUT ASIDE FROM
PIT/MGW/ZZV, IMPACTS ARE LIKELY TO BEGIN JUST OUTSIDE OF THE
CURRENT TAF PERIOD.
OUTLOOK...
TRANSITION TO NW FLOW WILL MAINTAIN PERIODS OF MVFR CLOUDS WITH
SHOWERS SATURDAY BEFORE HIGH PRESSURE AND DRY ADVECTION FAVOR
VFR SATURDAY NIGHT. THERE IS A HIGH PROBABILITY FOR A PROLONGED
PERIOD OF VFR AND DRY WEATHER SUNDAY INTO EARLY NEXT WEEK.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...CRAVEN
NEAR TERM...MILCAREK
SHORT TERM...CRAVEN
LONG TERM...CRAVEN
AVIATION...MLB
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page