423
FXUS61 KPBZ 301802
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
202 PM EDT SUN MAR 30 2025
SYNOPSIS
ABOVE NORMAL TEMPERATURES CONTINUE WITH SEVERE THUNDERSTORMS
POSSIBLE SUNDAY NIGHT. A BRIEF BIT OF DRIER AND COOLER WEATHER
IS EXPECTED TUESDAY BEFORE TEMPERATURES AND RAIN CHANCES GO ON
THE RISE AGAIN TO CLOSE OUT THE WEEK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- RAIN COVERAGE LESSENS BY LATE AFTERNOON.
- LINE OF STORMS POSSIBLE OVERNIGHT WITH ALL HAZARDS ON THE
TABLE.
- WELL ABOVE AVERAGE TEMPERATURES CONTINUE.
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THE SECOND PUSH OF RAIN HAS OVERSPREAD THE AREA EARLY THIS
AFTERNOON ALONG A FOCUSED AREA OF CONVERGENCE ON THE NOSE OF AN
ADDITIONAL 850 MB JET. HIGHER PWAT AIR UP TO 1.2" HAS ADVECTED
IN WITH THIS PLUME OF MOISTURE WHICH IS RESULTING IN MORE
MODERATE RAIN AT TIMES, BUT WITH ALL THE MORNING CLOUD COVER,
THERE HAS BEEN LITTLE ROOM FOR DESTABILIZATION. THIS LEAVES
LITTLE ROOM FOR ANY CONVECTIVE ACTIVITY THROUGH THE AFTERNOON
HOURS. HOURLY RAIN RATES LOOK TO BE UNDER CONTROL OVERALL WITH
THE HREF MAX ONE HOURLY VALUES NOT TOPPING AROUND TWO TENTHS OF
AN INCH AND THE MAX SIX HOURLY VALUES FROM THROUGH 6PM AROUND
HALF TO SIX TENTHS OF AN INCH.
WIND WILL BE GUSTY AT TIMES AS WELL WITH MIXING INTO
THE LOW LEVEL JET. PROBABILITY FOR GUSTS >30 MPH SIT AROUND
60-70%. CLOUD COVER AND RAIN WILL MUTE DAYTIME HEATING DESPITE
THE STRONG SOUTHWEST WIND, BUT HIGHS WILL STILL TOP OUT IN THE
MID TO UPPER 60S.
AS WE MOVE INTO THIS EVENING, A LINE OF SHOWERS AND
THUNDERSTORMS CURRENTLY DEVELOPING IN EASTERN ILLINOIS THIS
AFTERNOON WILL PROGRESS EASTWARD ALONG A PRE-FRONTAL TROUGH
MOVING INTO OUR EASTERN OHIO COUNTIES TONIGHT AROUND MIDNIGHT.
CAMS HAVE BEEN WAFFLING AROUND WITH HOW FAR EAST THE LINE
PROGRESSES BEFORE IT WEAKENS. IN GENERAL, THEY OFTEN STRUGGLE
WITH THE LIFETIME OF DECAYING CONVECTIVE COMPLEXES AND WANT TO
DISSIPATE THEM TOO QUICKLY. THAT WAS THE CASE FOR MANY SEQUENCES
OF RUNS UP TO THIS MORNING WITH DISSIPATION IN EASTERN OHIO,
BUT THE 12Z GUIDANCE FLIPPED TO A BIT MORE AGGRESSIVE WITH THE
LINE MAINTAINING ITSELF INTO WESTERN PENNSYLVANIA. HREF PROBS
FOR >500 J/KG OF CAPE CUT OFF RAPIDLY RIGHT ON A ZANESVILLE TO
COSHOCTON LINE AFTER SUNSET TONIGHT. HOWEVER, THE PROBS FOR AT
LEAST 100 J/KG HAS SHIFTED FURTHER EAST AND IS AS HIGH AS 50% UP
TO THE PA BORDER. THIS LENDS HIGHER CONFIDENCE IN IMPACTS AT
LEAST IN EASTERN OHIO, BUT STILL LESS CONFIDENCE FARTHER EAST.
KINEMATICALLY, FORECAST SOUNDINGS SUGGEST THAT THE BULK OF THE
SHEAR WILL BE PACKED IN THE LOWER 3 KM (~35 KT 0-3 KM SHEAR AND
~40 KT 0-6 KM SHEAR), AND THERMODYNAMICALLY, A GOOD CHUNK OF THE
AVAILABLE INSTABILITY ALSO IN THE LOWER LEVELS WITH 3CAPE
VALUES BETWEEN 60-100 J/KG. THIS MAY HAVE A TWO FOLD EFFECT IN
THAT 1) IT CAN HELP OVERCOME THE MARGINAL INSTABILITY AND
MAINTAIN THE LINE AND 2) SUGGESTS ANOTHER ROUND OF QLCS TORNADO
POTENTIAL, ESPECIALLY IN ANY SEGMENTS OF THE LINE THAT BOW AND
ORIENT MORE NORTHWEST TO SOUTHEAST IN ALIGNMENT WITH THE 0-3 KM
SHEAR VECTOR. DAMAGING WIND WILL BE THE PRIMARY HAZARD, BUT IN
COMPARISON TO OUR LAST EVENT, THE LOW-LEVEL WIND FIELD LOOKS
LESS POTENT, SO THOSE SIGNIFICANT GUSTS TO 80+ MPH ARE LESS
LIKELY.
THE ONE WRINKLE IN THIS IS THAT POINT SOUNDINGS FROM SOME OF
THE CAMS HAVE A SHALLOW STABLE LAYER NEAR THE SURFACE. THE
QUESTION WILL BE IF THE FORCING IS STRONG ENOUGH TO PUNCH
THROUGH IT. IF SO, ALL HAZARDS ARE ON THE TABLE. IF NOT, THIS
WOULD MITIGATE THE WIND AND TORNADO THREAT.
SHORT TERM /MONDAY/
KEY MESSAGES:
- SHOWER/STORM CHANCES DECREASE MONDAY MORNING
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A STRONG MODEL CONSENSUS SHOWS THE EASTWARD PROGRESSION OF THE
SURFACE FRONT PICKING UP SPEED NEAR SUNRISE ON MONDAY AS THE
ATTENDANT UPPER-LEVEL TROUGH ADVANCES INTO THE OH VALLEY. FASTER
EASTWARD PROGRESSION OF THE FRONT MONDAY MORNING COULD SET UP A
FAVORABLE TIME WINDOW FOR MUCH OF OUR REGION TO AVOID THE BRUNT
OF ANY SEVERE WEATHER EARLY ON MONDAY. MODEL CONSENSUS IS VERY
STRONG IN SHOWING MOST OF THE DESTABILIZATION MONDAY WELL EAST
OF THE RIDGES TOWARDS THE I-81 CORRIDOR. THIS LEAVES A NON-ZERO
BUT LOW CHANCE THAT IMPACTFUL SEVERE STORMS CAN FIRE ALONG THE
FRONT BRIGHT AND EARLY MONDAY MORNING AS THE FRONT CROSSES THE
REMAINDER OF OUR REGION.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL ON MONDAY.
LONG TERM /MONDAY NIGHT THROUGH SUNDAY/
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
-------------------------------------------------------------------
DRY AND COOLER CONDITIONS SETTLE IN TUESDAY BEHIND THE COLD
FRONT. BOTH ARE RATHER SHORT-LIVED AS ANOTHER SYSTEM CLIMBS
THROUGH THE UPPER MIDWEST ON WEDNESDAY DRAGGING A WARM FRONT
BACK THROUGH THE REGION. THIS USHERS IN THE RETURN OF ABOVE
NORMAL TEMPERATURES AND RAINFALL.
THERE LOOKS TO BE POTENTIAL FOR A BOUNDARY TO STALL ACROSS THE
OHIO VALLEY BEGINNING LATE-WEEK AND LASTING INTO THE WEEKEND.
THE EXACT PLACEMENT AND ANY FURTHER WOBBLING OF THIS STATIONARY
BOUNDARY WILL BE VERY IMPORTANT TO THE EXPECTED IMPACTS BUT IT
LOOKS LIKELY THAT SOMEWHERE IN THE OH VALLEY IS IN FOR ROUNDS OF
RAINFALL AND THE POSSIBILITY OF HIGH WATER IMPACTS. IT REMAINS
VERY EARLY TO SAY EXACTLY WHERE THESE IMPACTS WILL BE GREATEST
BUT CLUSTERED ANALYSIS OF LONG-RANGE ENSEMBLES YIELD SEVERAL
DAYS NEXT WEEK WHERE THE CHANCE TO SEE >1 INCH OF RAINFALL IN
24HRS IS ABOVE 30% IN OUR REGION.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
ANOTHER ROUND OF RAIN ON THE NOSE OF AN IMPINGING 40 KNOT LOW-
LEVEL JET IS MOVING ACROSS THE AREA THIS AFTERNOON BRINGING
MORE RESTRICTIONS THAN THE EARLIER ONE WHICH AIDED IN SATURATING
THE DRY SUB-CLOUD LAYER. MOSTLY MVFR CIGS AND VIS HAVE
PREVAILED IN LIGHT TO MODERATE RAIN, THOUGH SOME EMBEDDED
HEAVIER RATES HAVE RESULTED IN PERIODIC DEGRADATION TO IFR. ONCE
THIS BATCH EXITS TO THE EAST, MVFR CIGS WILL TAKE AN EXTRA HOUR
TO TWO TO LIFT TO A BRIEF PERIOD OF VFR FAVORED UNTIL THE NEXT
LINE OF SHOWERS/STORMS ARRIVES LATE THIS EVENING. SURFACE WIND
GUSTS OF UP TO 30 MPH ARE POSSIBLE THROUGH THE AFTERNOON.
A LINE OF CONVECTION WILL BE PROGRESSING ACROSS OHIO TONIGHT,
AND THERE'S UNCERTAINTY HOW FAR EAST IT WILL BE ABLE TO HANG ON
WITH UNFAVORABLE TIMING WELL AFTER SUNSET. MODEL CONSENSUS IS
THAT IT HANGS ON AT LEAST INTO EASTERN OHIO AFFECTING ZZV WITH
HIGHEST CONFIDENCE AND LIKELY AS FAR EAST AS PIT/AGC. MOST
LIKELY TIMING FOR ZZV IS AROUND 02Z, PIT AT 04Z, AND LBE AT 06Z
IF IT HOLDS TOGETHER THAT FAR EAST. INTRODUCED PREVAILING LOW
END MVFR CONDITIONS WITH TEMPO GROUPS FOR IFR TSRA AT ALL SITES
AROUND THE TIMEFRAME OF THE HIGHEST IMPACT. GUSTS ARE LIKELY TO
BE STRONGER AND MORE SPORADIC WITH THE LINE OF CONVECTION.
THE COLD FRONT ITSELF WILL PASS THROUGH MONDAY MORNING WITH
PERHAPS A FEW SHOWERS ACCOMPANYING IT. COLD ADVECTION IN ITS
WAKE WILL REINFORCE LOW CLOUD COVERAGE AND MAINTAIN A 60-80%
CHANCE OF MVFR CIGS INTO THE DAYTIME HOURS. GUSTY WIND WILL
CONTINUE WITH 60-80% PROBABILITIES OF 30 MPH.
OUTLOOK...
VFR RETURNS TUESDAY UNDER HIGH PRESSURE. 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...MLB
NEAR TERM...MLB
SHORT TERM...88/AK
LONG TERM...88/AK
AVIATION...MLB
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