814
FXUS61 KPBZ 311851
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
251 PM EDT MON MAR 31 2025
SYNOPSIS
SHOWERS AND A FEW THUNDERSTORMS EAST OF PITTSBURGH WILL EXIT
THIS EVENING WITH A COLD FRONT. DRY WEATHER AND COOL
TEMPERATURES ARE EXPECTED TUESDAY WITH HIGH PRESSURE. ANOTHER
FRONT WILL APPROACH AND STALL NEAR OUR REGION WEDNESDAY NIGHT
AND LINGER INTO THE UPCOMING WEEKEND. THIS FRONT WILL PRESENT
SEVERE WEATHER THREATS WEDNESDAY AND THURSDAY, AND A HEAVY RAIN
THREAT INTO THE WEEKEND.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE EAST OF
PITTSBURGH INTO THE EVENING WITH A COLD FRONT.
- SEVERE WEATHER THREAT APPEARS QUITE LOW.
- GUSTY WIND AND FALLING TEMPERATURES BEHIND THE FRONT.
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THE COLD FRONT IS CURRENTLY MOVING ACROSS THE CWA, NOW EAST OF
PITTSBURGH, WITH JUST A THIN BAND OF SHOWERS ALONG IT.
SHORTWAVE ENERGY ROTATING ACROSS THE MIDDLE OHIO VALLEY AND WEST
VIRGINIA WILL PROVIDE A PUSH OF MOISTURE AND LIFT TO AREAS
SOUTHEAST OF PITTSBURGH, LEADING TO AN INCREASE IN COVERAGE OF
SHOWERS AND STORMS AHEAD OF THE FRONT OVER THE NEXT FEW HOURS.
THE RISK OF SEVERE WEATHER WITH ANY THUNDERSTORMS APPEARS QUITE
LOW, WITH MINIMAL BUOYANCY EXPECTED TO DEVELOP IN THE FAR
SOUTHEASTERN CWA AHEAD OF THE BOUNDARY, ALTHOUGH AMPLE SHEAR
DOES EXIST IN A DEEP-LAYER SENSE. MACHINE-LEARNING GUIDANCE IS
UNIMPRESSED WITH THE SEVERE THREAT AS WELL. STILL, NON-SEVERE
GUSTY WIND WILL BE POSSIBLE WITH THESE STORMS, THE THREAT OF
WHICH WILL END DURING THE EVENING WITH THE DEPARTURE OF THE
FRONT. PERHAPS A QUARTER TO HALF-INCH OF RAIN IS POSSIBLE WITH
ANY THUNDERSTORMS THAT DEVELOP IN OR NEAR THE NORTHERN WV
RIDGES. TEMPERATURES WILL BEGIN TO DROP SOON AFTER FROPA WITH
COLD ADVECTION COMMENCING QUICKLY BEHIND.
ALTHOUGH PRECIPITATION WILL BE LARGELY OVER BY MIDNIGHT,
MOISTURE TRAPPED UNDERNEATH A SUBSIDENCE INVERSION WILL KEEP
PLENTY OF CLOUD COVER IN THE REGION OVERNIGHT. LOWS WILL BE
MUCH COOLER THAN RECENT NIGHTS IN NORTHWEST FLOW WITH VALUES
DIPPING NEAR TO BELOW FREEZING NORTH OF I-70, AND INTO THE
MIDDLE 30S IN THE FAR SOUTHERN CWA.
SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/
KEY MESSAGES:
- DRY WEATHER THROUGH TUESDAY NIGHT.
- SLIGHTLY BELOW-NORMAL HIGHS TUESDAY, WITH MODERATION BEGINNING
TUESDAY NIGHT.
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CROSSING SURFACE HIGH PRESSURE WILL PROVIDE A QUIET WEATHER DAY
ON TUESDAY, WITH SOME SUNSHINE FORECAST AFTER LOW-LEVEL MIXING
AND WARMING HELP TO DISSIPATE THE MORNING CLOUD COVER. DAYTIME
HIGHS SHOULD END UP A FEW DEGREES BELOW CLIMATOLOGY.
FLAT MID-LEVEL RIDGING CROSSES AROUND 00Z WEDNESDAY, WITH WARM
ADVECTION TUESDAY NIGHT PROVIDING MODERATING LOW TEMPERATURES
AND AN INCREASE IN MID AND UPPER LEVEL CLOUD COVER.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
KEY MESSAGES:
- ABOVE AVERAGE TEMPERATURES WEDNESDAY THROUGH SATURDAY
- SEVERE THUNDERSTORM POTENTIAL WEDNESDAY AND THURSDAY
- POTENTIAL FOR HEAVY RAIN THURSDAY INTO SATURDAY
- QUIETER WEATHER POSSIBLE SUNDAY/MONDAY
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ENSEMBLES ARE SUGGESTING THAT THERE IS HIGH CONFIDENCE IN RIDGING
SETTING UP OFF OF THE SOUTHEAST CONUS COAST STARTING ON WEDNESDAY
AND LASTING INTO THE WEEKEND. THIS WOULD LIKELY SET UP PERSISTENT
SOUTHWEST FLOW ALOFT ACROSS THE OHIO VALLEY. A FRONTAL BOUNDARY WILL
LIKELY ADVANCE INTO THIS AREA AND STALL GENERALLY FROM THURSDAY INTO
THE WEEKEND, WITH SOME WOBBLES IN ITS POSITION DURING THIS PERIOD.
THIS FRONT WILL PRESENT THE POTENTIAL FOR BOTH SEVERE WEATHER AND
FLOODING THREATS.
THE BOUNDARY FIGURES TO APPROACH THE REGION WEDNESDAY EVENING, WITH
PERHAPS A STRONGLY-FORCED LINE OF STORMS IN OR NEAR EASTERN OHIO
APPROACHING AS EARLY AS THE AFTERNOON. ENSEMBLES HAVE LITTLE
DOUBT THAT THERE WILL BE SUFFICIENT DEEP-LAYER SHEAR, WITH THE
VAST MAJORITY OF MEMBERS SUGGESTING AT LEAST 50 KNOTS IN THE
SURFACE TO 500MB LEVEL. CAPE LEVELS ARE MORE UNCERTAIN, WITH
BEST PROBABILITIES OF A FEW HUNDRED J/KG (GREATER THAN 30
PERCENT OR SO) TO THE WEST OF I-77. PROBABLY NOT COINCIDENTALLY,
THIS IS WHERE SPC HAS A DAY 3 SLIGHT RISK OUTLINED (AS DOES CSU
MLP GUIDANCE), WITH A MARGINAL RISK ACROSS THE REMAINDER OF OUR
CWA, WHERE STORMS WOULD TRAVERSE DURING A PERIOD OF DIURNAL
STABILIZATION. A DAY 4 SEVERE RISK IS ALSO OUTLINED FOR THE
MAJORITY OF THE CWA AS THE FRONT LINGERS, WITH BUOYANCY ONCE
AGAIN MORE UNCERTAIN THAN SHEAR. AREAS SOUTH OF PITTSBURGH MIGHT
HAVE A BIT HIGHER THREAT.
THE SIGNALS FOR HEAVY RAIN WITH THIS FRONT ARE CERTAINLY THERE. AN
EXTENDED PERIOD OF PRECIPITABLE WATER VALUES NEAR OR ABOVE THE TOP
END OF CLIMATOLOGY IS POSSIBLE FROM WEDNESDAY NIGHT THROUGH
SATURDAY, AND WITH LIKELY PERIODS OF CONVERGENT FLOW WITH THE FRONT,
THERE IS POTENTIAL FOR SOME IMPRESSIVE 72-HOUR RAINFALL TOTALS,
PARTICULARLY IN EASTERN OHIO. GEFS M-CLIMATE PROGS ALSO SHOW THE
POTENTIAL FOR AN AXIS OF RAINFALL EXTENDING INTO FAR WESTERN PA
THAT COULD EXCEED THE 20-YEAR CLIMATOLOGY RELATIVE TO GEFS
REFORECASTS - BOTTOM LINE, A POTENTIALLY SIGNIFICANT RAINFALL
EVENT FOR THE OHIO VALLEY. WHILE THE POSSIBLE RAINFALL TOTALS
GENERALLY ARE HIGHER TO OUR SOUTHWEST, NBM PROBABILITIES OF 2
INCHES OR MORE OF TOTAL RAIN FROM 8 AM THURSDAY THROUGH 8 AM
SATURDAY ARE 50 PERCENT OR GREATER IN EASTERN OHIO, AND SLOWLY
DROP OFF EAST OF THE PA/OH BORDER. 90TH PERCENTILE VALUES OF 3
TO 4 INCHES SHOW UP DURING THIS PERIOD, WHICH COULD REPRESENT
VALUES IN A RELATIVELY SMALL BAND WHERE CONVECTION ENDS UP BEING
MOST FAVORED. FLASH FLOODING MAY BECOME A CONCERN IN SPOTS
DEPENDING ON WHERE THE HEAVIER AXIS OF CONVECTION SETS UP. LONG-
RANGE ENSEMBLE RIVER GUIDANCE ALSO SHOWS THE POTENTIAL FOR
PLENTY OF STRONG RISES ON AREA RIVERS, WITH AT LEAST ACTION
STAGES POSSIBLE FOR MUCH OF THE AREA, WITH SOME POTENTIAL FOR
MINOR RIVER FLOODING IN AT LEAST EASTERN OHIO. IT'S STILL A BIT
TOO EARLY FOR ANY FLOOD WATCHES, BUT THESE MAY BECOME NECESSARY
OVER THE NEXT DAY OR TWO.
ABOVE-NORMAL TEMPERATURES WILL ACCOMPANY ALL OF THIS RAIN INTO
THE WEEKEND. IMPROVEMENT IN THE WEATHER PATTERN IS POSSIBLE BY
SUNDAY OR MONDAY AS A STRONGER GREAT LAKES SHORTWAVE COULD
FINALLY KICK THE BOUNDARY TO THE EAST, ALTHOUGH THERE IS MODEL
DISAGREEMENT THIS FAR OUT ON TIMING AND STRENGTH. BELOW-NORMAL
TEMPERATURES COULD RETURN WITH SOME OF THESE SOLUTIONS, ALONG
WITH A DRIER PATTERN.
AVIATION /18Z MONDAY THROUGH SATURDAY/
MVFR CONDITIONS WILL REMAIN THE THEME THROUGH TONIGHT. LOW LEVEL
COLD ADVECTION IN THE WAKE OF THE MORNING COLD FRONT WILL REINFORCE
CLOUD COVERAGE BENEATH A SINKING INVERSION THROUGH THE OVERNIGHT
HOURS TONIGHT. FKL/DUJ ARE MORE LIKELY TO GO IFR AFTER 00Z OR
SO WITH 50-70% PROBABILITIES FILTERING IN WITH INCREASED LAKE
MOISTURE. REDEVELOPMENT OF SHOWERS ALONG THE EXITING BOUNDARY IS
LIKELY THIS AFTERNOON EAST OF PIT. HIGHEST CHANCE TO SEE
IMPACTS TO VISIBILITY IN RAIN WILL BE LBE/MGW, BUT THE BACK EDGE
OF THE PRECIP SHIELD IS GOING TO BE CLOSE TO BOTH PORTS. GIVEN
UNCERTAINTY IN DIRECT IMPACTS, OPTED TO TEMPO IN RESTRICTIONS IN
RAIN THIS AFTERNOON. WIND GUSTS OUT OF THE NORTHWEST TODAY IN
THE COLD ADVECTION REGIME ARE FAVORED TO REACH 20-25 MPH.
SOUNDINGS KEEP THE LOW LEVELS MIXED OVERNIGHT SO STILL EXPECT
GUSTS TO CONTINUE OVERNIGHT.
THE MID-LEVEL TROUGH AXIS WILL PASS THROUGH TONIGHT AND BACK FLOW TO
THE WEST/NORTHWEST AND DRIER AIR WILL WORK IN ALLOWING CLOUD
COVERAGE TO BEGIN TO SCATTER. WITH DAYTIME MIXING ON TUESDAY,
THE MOISTURE WILL ERODE AND VFR CONDITIONS RETURN WITH HIGH
CONFIDENCE IN THE MORNING HOURS. ASIDE FROM SOME CIRRUS
STREAMING IN AT THE END OF THE CURRENT TAF PERIOD, SKIES WILL BE
MOSTLY CLEAR BY THE AFTERNOON HOURS.
OUTLOOK...
LOW PRESSURE MAY BRING ANOTHER ROUND OF RAIN AND RESTRICTIONS
WEDNESDAY INTO THURSDAY WITH AN UNSETTLED PATTERN CONTINUING TO
CLOSE OUT THE WEEK.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...CL
NEAR TERM...CL
SHORT TERM...CL
LONG TERM...CL
AVIATION...MLB
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