075
FXUS61 KPBZ 202009
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
409 PM EDT FRI MAR 20 2026
WHAT HAS CHANGED
SEVERE STORM POTENTIAL HAS TRENDED DOWN A BIT FOR THIS AFTERNOON
AND EVENING, GIVEN THE PRECEDING RAIN HINDERING HEATING. GIVEN
STRONG HEATING AND FAVORABLE DYNAMICS SUNDAY, A SMALL UPTICK IN
STRONG STORM POTENTIAL IS NOTED.
KEY MESSAGES
1) LOW POTENTIAL FOR STRONG TO SEVERE STORMS DURING THE LATE
AFTERNOON AND EVENING, WITH HAIL APPEARING TO BE THE PRIMARY
THREAT.
2) SOMEWHAT BETTER STORM POTENTIAL ON SUNDAY, WITH ALL SEVERE
THREATS IN PLAY.
DISCUSSION
KEY MESSAGE 1...
SEVERE POTENTIAL FOR THIS AFTERNOON APPEARS TO BE ON THE
DOWNSWING OVERALL. AN AREA OF LARGELY STRATIFORM RAIN IS
ADVANCING SOUTHWARD INTO THE REGION AHEAD OF A MID-LEVEL
SHORTWAVE. AN ASSOCIATED SURFACE COLD FRONT AND PERHAPS SOME
LEFT EXIT REGION JET DYNAMICS ARE SUPPLYING THE LIFT, WHILE
PRECIPITABLE WATER SLOWLY INCREASES IN MEAN LOW-LEVEL SOUTHWEST
FLOW. THIS RAIN SHOULD HINDER DESTABILIZATION DURING THE
AFTERNOON, AND EVEN THE THICKENING CLOUDS AHEAD OF THIS RAIN ARE
INHIBITING SURFACE HEATING. CAM GUIDANCE SUPPORTS THE NOTION
THAT HEALTHY CONVECTIVE UPDRAFTS WILL BE HARD TO COME BY, WITH
HREF MEAN SURFACE-BASED CAPE TOPPING OUT AT 300 J/KG OR LESS.
THAT SAID, THE POST-FRONTAL ENVIRONMENT DURING THE EVENING COULD
SUPPORT A LOW-END RISK FOR HAIL. WHILE THE BOUNDARY LAYER
REMAINS STABLE DUE TO THE RAIN AND THE SETTING SUN, STEEPENING
MID-LEVEL LAPSE RATES, APPROACHING THE 7-8 C/KM RANGE, MAY
SUPPORT SOME ELEVATED INSTABILITY (MUCAPE OF AROUND 500 J/KG).
COMBINED WITH 0-6KM SHEAR STILL BETWEEN 40 AND 50 KNOTS, POST-
FRONTAL CONVECTION SUGGESTED BY CAMS COULD HAVE SUFFICIENT
UPDRAFT/DOWNDRAFT SEPARATION FOR MARGINALLY SEVERE HAIL IN THE
STRONGEST CELLS. IF SOME SORT OF SURFACE-BASED INSTABILITY CAN
DEVELOP, ONE OR TWO STRONG TO MARGINALLY SEVERE WIND GUSTS COULD
BE POSSIBLE.
QPF TOTALS THROUGH TONIGHT TOP OUT IN THE 0.25 TO 0.50 INCH
RANGE, WITH THE HIGHER TOTALS LIKELY IN THE RIDGES AS SUPPORTED
BY HI-RES MODEL DATA. OF COURSE, LOCALLY HIGHER TOTALS COULD BE
POSSIBLE IN ANY HEAVIER STORMS. ANY SHOWERS/STORMS SHOULD
LARGELY PULL SOUTH OF THE REGION BY 06Z WITH THE DEPARTING
BOUNDARY.
KEY MESSAGE 2...
AFTER A QUIET SATURDAY, A SOMEWHAT MORE ROBUST THREAT FOR
SEVERE WEATHER IS PRESENT FOR SUNDAY. WARM FRONTAL PASSAGE
SATURDAY NIGHT, ATTACHED TO GREAT LAKES LOW PRESSURE, ALLOWS FOR
SOUTHWEST FLOW PROMOTING STRONG HEATING DURING THE SUNDAY
DAYLIGHT HOURS. WELL-ABOVE NORMAL HIGH TEMPERATURES ARE
FORECAST, SUPPORTED BY 850MB TEMPERATURES APPROACHING 15C. HIGHS
WILL MAINLY BE IN THE 70S, PERHAPS NEAR 80 IN THE VICINITY OF
THE MASON-DIXON LINE. MUCAPE LEVELS OF AT LEAST 500-1000 J/KG
ARE SUGGESTED BY ENSEMBLES SUNDAY AFTERNOON, WITH A LOT OF THAT
IN THE IDEAL HAIL GROWTH ZONE. 0-6KM SHEAR MAY TOP OUT IN THE
RANGE OF 50-60 KNOTS. AS ANOTHER COLD FRONT DROPS ACROSS THE
REGION DURING THE AFTERNOON AND EVENING, SOME SUPERCELL
STRUCTURES MAY BE SUPPORTED IN THIS ENVIRONMENT, WITH ALL SEVERE
HAZARDS ON THE TABLE. AT PRESENT, PARAMETERS APPEAR BEST
ALIGNED IN EASTERN OHIO. THIS IS WHERE SPC HAS PLACED A SLIGHT
(LEVEL 2 OF 5) SEVERE RISK, WITH A MARGINAL (LEVEL 1 OF 5) IN
MUCH OF THE REST OF THE CWA AWAY FROM THE RIDGES. WEAKENING
CONVECTION WOULD ACCOMPANY THE FRONT THROUGH THE NIGHT, WITH DRY
WEATHER AND COOLER TEMPERATURES RETURNING FOR MONDAY.
AVIATION /20Z FRIDAY THROUGH WEDNESDAY/
SOUTHWESTERLY WIND GUSTS PERSIST TODAY AHEAD OF A SURFACE COLD
FRONTAL PASSAGE. RAIN HAS ALREADY BEGAN ALOFT, WHICH WILL
PROGRESSIVELY FILTER ITS WAY TO THE SURFACE AT PORTS OVER THE
NEXT COUPLE HOURS. THROUGH 00Z, SHOWERS WILL BE HIT OR MISS, AND
WHILE THUNDER COULDN'T BE COMPLETELY RULED OUT, ITS GENERALLY
LESS THAN 20% LIKELY AT ANY GIVEN PORT. ALONG/BEHIND THE FRONT
ITSELF, THE ENVIRONMENT MAY BE A BIT MORE UNSTABLE, BUT THERE
IS A LOW PROBABILITY OF CONVECTIVE DEVELOPMENT, THEREFORE,
MAINTAINED PROB30 GROUPS AT ANY PORTS WHERE AN ISOLATED
THUNDERSTORM IS MOST POSSIBLE AFTER SUNSET.
INTO TONIGHT, RECENT RAINS AND SATURATION IN WAKE OF THE FRONT
WILL ALLOW THE CHANCE OF WIDESPREAD MVFR CIGS, WITH A CHANCE OF
IFR AT DUJ/FKL. DRY AIR ADVECTION IN WAKE OF THE FRONT WILL
PROGRESSIVELY IMPROVE CIGS INTO THE MORNING HOURS SATURDAY.
WIDESPREAD RETURN TO VFR ARE LIKELY BY 16Z.
OUTLOOK... VFR CIGS RETURN LATE MORNING SATURDAY. A FRONTAL PASSAGE
SUNDAY COULD RETURN STRONG THUNDERSTORMS TO THE REGION DURING THE
AFTERNOON.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL
AVIATION...MILCAREK
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