557
FXUS61 KPBZ 292146
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
546 PM EDT SAT MAR 29 2025
SYNOPSIS
ABOVE NORMAL TEMPERATURES THIS WEEKEND WITH INCREASING RAIN AND
THUNDERSTORM CHANCES LATE SUNDAY INTO EARLY MONDAY. DRY TUESDAY
WITH SLIGHTLY BELOW NORMAL TEMPERATURES AHEAD OF ANOTHER WARMUP
AND UNSETTLED WEATHER TO CLOSE OUT THE WEEK.
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
KEY MESSAGES:
- WELL ABOVE AVERAGE TEMPERATURES CONTINUE
- POTENTIAL RECORD MINT TEMPS
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INCREASING LOW AND MID-LEVEL SUBSIDENCE UNDER A RIDGE AXIS HAS
DISSOLVED LIGHT RAIN SHOWER ACTIVITY ACROSS THE REGION. WITH
SOME CLEARING SOUTH OF I-70, SOME AREAS ARE NEARING 80 DEGREES.
CLOUD COVERAGE ELSEWHERE WILL BE THE ONLY THING HAMPERING
AFTERNOON HIGH TEMPERATURES AS STOUT SOUTHWEST FLOW PROMOTES
WARM ADVECTION.
TONIGHT, SURFACE LOW PRESSURE WILL DEEPEN OFF TO OUR WEST AND
BEGIN TO SLIDE TOWARD THE GREAT LAKES REGION. AS IT DOES SO,
IT'LL DRAG THE WARM FRONT FARTHER NORTH AND LOCALLY INCREASE THE
PRESSURE GRADIENT. DESPITE BOUNDARY LAYER DECOUPLING OVERNIGHT,
WEAK WARM ADVECTION IN GRADIENT-INDUCED SOUTHERLY FLOW WILL
PROVIDE ABOVE NORMAL LOW TEMPERATURES AND CHALLENGE SOME RECORD
LOW MINTS (60F AT PIT, 59F AT HLG, 59F AT PHD).
WITH THE BREAK DOWN OF THE RIDGE, EXPECTED PRECIPITATION CHANCES
TO INCREASE FROM THE SOUTH AND THE WEST AFTER 2AM.
SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/
KEY MESSAGES:
- SHOWER/STORM CHANCES INCREASE SUNDAY AND MONDAY
- UNCERTAINTY TO SEVERE THREAT AND TIMING OF FRONT
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PRECIPITATION CHANCES WILL INCREASE EARLY SUNDAY WITH A
CROSSING SHORTWAVE. EXPECT AN AREA OF SHOWERS TO DEVELOP AHEAD
OF THE WAVE AND SPREAD ACROSS THE UPPER OHIO VALLEY SUNDAY
MORNING. SHOWERS WILL LIKELY CONTINUE THROUGH MOST OF THE DAY AS
A PLUME OF DEEP MOISTURE (PWATS 2-3 STANDARD DEVIATIONS ABOVE
NORMAL) WILL DRIVE NORTHEASTWARD ON THE WESTERN FLANK OF THE
EASTWARD DRIFTING RIDGE. DONT SEE MUCH ATMOSPHERIC
DESTABILIZATION UNTIL LATE IN THE DAY, SO THE RISK FOR
THUNDERSTORMS WOULD INCREASE DURING THE LATE AFTERNOON AND
THROUGH THE EVENING. THE INSTABILITY IS NOT OVERLY IMPRESSIVE
(200-500 J/KG) WITH THE STRONGEST BUOYANCY OVER PORTIONS OF
EASTERN OHIO. THE HEADACHE WILL BE THAT AN UPPER-LEVEL DRY SLOT
WILL PASS OVER THE REGION SUNDAY EVENING WHICH MAY LEAD TO A
DECREASE IN ACTIVITY FOR A PORTION OF THE EVENING AND OVERNIGHT
HOURS.
THE BIG QUESTIONS COME SUNDAY NIGHT, MOSTLY AFTER 7PM, AND
MONDAY MORNING. THE COLD FRONTS EASTERN PROGRESSION WILL SLOW
SUNDAY NIGHT AS THE RIDGE WILL NOT EASILY GIVE WAY AND THE MAIN
TROUGH AXIS WILL BE WELL TO THE NORTHWEST OF THE SURFACE
BOUNDARY. SINCE WE EXPECT MUCH OF THE CONVECTION TO BE DRIVEN BY
THE SURFACE FRONT, IT MAY BE TOO FAR WEST TO HAVE THAT MUCH OF
AN INFLUENCE UNTIL VERY LATE SUNDAY NIGHT OR EVEN MONDAY. THE
OTHER ISSUE IS THAT MOST, IF NOT ALL OF THE MODEL DATA, IS IN
AGREEMENT THAT THE ATMOSPHERE WILL STABILIZE SUNDAY NIGHT, WHICH
COULD FORCE THE CONVECTION ALONG THE FRONT TO BE FORCED TO AN
AREA WITH HIGHER BUOYANCY. MODELS ARE PORTRAYING A SCENARIO
WHERE THE CONVECTION OVER WESTERN OHIO WILL DIVE SOUTHEASTWARD
TOWARD KY AN TN, WHERE MUCH MORE UNSTABLE AIR WILL REST. THIS
COULD LEAD TO AN OUTCOME WHERE WESTERN AND SOUTHERN PORTIONS OF
THE FORECAST AREA GET CLIPPED WITH STRONGER STORMS. STILL A LOT
OF UNCERTAINTY ON THE THREAT FOR STRONG TO SEVERE STORMS SUNDAY
NIGHT AND WHERE THEY MAY IMPACT.
FRONT WILL FINALLY BEGIN TO MOVE EASTWARD AT A FASTER PACE
MONDAY MORNING AS THE MAIN TROUGH AXIS WILL DIG INTO THE MIDWEST
AND GIVE THE FRONT A PUSH. THE RISK FOR SHOWERS AND STORMS WILL
CONTINUE THROUGH MONDAY, AS THE BOUNDARY FINALLY DOES EXIT TO
THE EAST MONDAY EVENING. MODELS ARE SHOWING SOME DESTABILIZATION
ON MONDAY AHEAD OF THE BOUNDARY, SO THE RISK FOR STRONG TO
SEVERE STORMS WILL CONTINUE, BUT UNCERTAINTY REMAINS HIGH.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL BOTH SUNDAY AND
MONDAY.
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/
KEY MESSAGES:
- A COOL-DOWN IS MOST LIKELY MONDAY NIGHT INTO TUESDAY.
- ABOVE AVERAGE TEMPERATURES WEDNESDAY THROUGH FRIDAY.
- POTENTIAL FOR HEAVY RAIN THURSDAY INTO SATURDAY
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DRY AND COOLER CONDITIONS ARE EXPECTED TUESDAY WITH ANOTHER WARM
UP BEGINNING ON WEDNESDAY. ABOVE NORMAL TEMPERATURES ARE THEN
EXPECTED THROUGH THE END OF THE WEEK WITH AN UNSETTLED WEATHER
PATTERN RETURNING ON WEDNESDAY.
THE NEXT TIME PERIOD WHERE THERE COULD BE HAZARDOUS WEATHER
APPEARS TO BE THURSDAY INTO SATURDAY. THERE IS THE POTENTIAL FOR
A STATIONARY BOUNDARY STRETCHING FROM THE MISSISSIPPI RIVER
VALLEY INTO THE OHIO RIVER VALLEY. THE MAIN THREAT WITH THIS
DISTURBANCE WOULD BE HIGH WATER (I.E. FLOODING AND ELEVATED
CREEKS AND RIVERS). PROBABILITY OF 1 INCH OF RAIN RANGES FROM
30-50%, WHICH IS PRETTY IMPRESSIVE FOR 5 DAYS OUT.
AVIATION /21Z SATURDAY THROUGH THURSDAY/
VFR IS EXPECTED TO BE THE RULE THROUGH TONIGHT. RECENT TREND IN
ACARS SOUNDINGS SHOWS CONTINUED MOISTENING OF THE MID-LEVELS
WITH MOISTURE ADVECTION AROUND THE 700 MB LEVEL IN WSW FLOW
ALOFT. THIS WILL SUPPORT CIGS JUST BELOW 10KFT WHICH WILL LIKELY
HOLD ON FOR MOST OF THE DAY TODAY. BROAD, WEAK FORCING HAS ALSO
MAINTAINED AN INCREASE IN RADAR RETURNS ACROSS THE AREA EARLY
THIS AFTERNOON, THOUGH COPIOUS SUB-CLOUD DRY AIR IS PREVENTING
THE BULK OF IT FROM REACHING THE GROUND. SOME OBS OF LIGHT RAIN
HAVE POPPED UP WITH NO ASSOCIATED RESTRICTIONS, SO HAVE
ADDRESSED THIS THREAT WITH TEMPOS AND PROB30S WHERE CONFIDENCE
IS HIGHEST.
DEEP MIXING INTO A 40-50 KNOT LOW LEVEL JET HAS PROMOTED GUSTS
TO 25-30 KNOTS AT THE SURFACE THIS AFTERNOON. THESE WILL
CONTINUE UNTIL SUNSET WHEN THE BOUNDARY LAYER DECOUPLES AND A
LIGHT SOUTHERLY GRADIENT WIND REMAINS OVERNIGHT.
AS A DIGGING CENTRAL CONUS TROUGH SHUNTS THE MID-LEVEL RIDGE
OFF TO THE EAST TONIGHT, BACKING SOUTHWESTERLY FLOW WILL
PROMOTE MOISTURE ADVECTION SATURATING THE PROFILE AND LOWERING
CIGS INTO SUNDAY MORNING. AS RAIN APPROACHES AROUND DAWN, IT
LOOKS AS THOUGH RESTRICTIONS INITIALLY COME FROM VIS AS THE
COLUMN SATURATES AND CLOUD BASES THEN LOWER. MVFR CIG PROBS
DON'T JUMP UP UNTIL CLOSER TO 15Z WITHIN MORE MODERATE RAIN.
JUST AFTER THE CURRENT TAF PERIOD, ENSEMBLE PROBS FOR IFR
INCREASE TO NEAR 70%.
OUTLOOK...
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED OVERNIGHT
SUNDAY NIGHT INTO MONDAY MORNING WITH A RETURN OF RESTRICTIONS.
VFR RETURNS TUESDAY UNDER HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...MLB
NEAR TERM...HEFFERAN/MLB
SHORT TERM...22/88
LONG TERM...22/88/HEFFERAN
AVIATION...MLB
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