144
FXUS61 KPBZ 202218
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
618 PM EDT FRI MAR 20 2026
WHAT HAS CHANGED
SEVERE STORM POTENTIAL HAS TRENDED DOWN A BIT FOR THIS EVENING
WITH THE DAYTIME RAIN AND CLOUDS HINDERING DESTABILIZATION.
GIVEN STRONG HEATING AND FAVORABLE DYNAMICS SUNDAY, A SMALL
UPTICK IN STRONG STORM POTENTIAL IS NOTED, AND SPC HAS EXPANDED
THE SLIGHT RISK INTO SOUTHWESTERN PENNSYLVANIA.
KEY MESSAGES
1) LOW POTENTIAL FOR STRONG TO SEVERE STORMS FRIDAY 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...
AN AREA OF STRATIFORM RAIN AND THICK CLOUD COVERAGE WITH LIFT
UNDER THE FAVORABLE UPPER JET EXIT REGION HAS CONTINUED TO
PLAGUE THE AREA INTO EARLY THIS EVENING. THE BACK EDGE OF THE
RAIN WILL MOVE NORTH TO SOUTH ACROSS THE AREA LIKELY CLEARING BY
8PM OR SO. QUICKLY ON THE HEELS OF THAT RAIN IS A COLD FRONT
FOLLOWING A SIMILAR PATH.
DESTABILIZATION THROUGH THE DAY WAS GREATLY INHIBITED BY THE
AFOREMENTIONED FACTORS, BUT THAT SAID, THE POST-FRONTAL
ENVIRONMENT COULD SUPPORT A LOW-END RISK FOR HAIL WITH ANY
STORMS AFTER 8PM OR SO. STEEPENING MID-LEVEL LAPSE RATES WITH
COLDER AIR FILTERING IN BEHIND THE FRONT, APPROACHING THE 7-8
C/KM RANGE, MAY SUPPORT SOME ELEVATED INSTABILITY (LATEST CAMS
SUGGESTING MUCAPE VALUES OF AROUND 500-800 J/KG). COMBINED WITH
0-6 KM SHEAR STILL BETWEEN 40 AND 50 KNOTS, ANY SUCCESSFUL
CONVECTION COULD HAVE SUFFICIENT UPDRAFT/DOWNDRAFT SEPARATION
FOR MARGINALLY SEVERE HAIL IN THE STRONGEST CELLS. THE BIG
QUESTION IS *IF* STORMS OCCUR AS A POST-FRONTAL ENVIRONMENT
TYPICALLY ISN'T WHERE YOU'D EXPECT DEVELOPMENT. BY THIS POINT,
SOUNDINGS ARE GENERALLY IN GOOD AGREEMENT THAT THE SURFACE IS
STABLE, OR AT WORST ISOTHERMAL, SO A DAMAGING WIND AND TORNADO
THREAT APPEARS TO BE ON THE VERY LOW SIDE.
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 AND LEAKING OVER INTO SOUTHWESTERN
PENNSYLVANIA. ACCORDINGLY, SPC HAS EXPANDED THE SLIGHT RISK
(LEVEL 2 OF 5) INTO SOUTHWESTERN PENNSYLVANIA, WITH A MARGINAL
RISK (LEVEL 1 OF 5) ENCOMPASSING THE REST OF OUR AREA.
WEAKENING CONVECTION WOULD ACCOMPANY THE FRONT THROUGH THE
NIGHT, WITH DRY WEATHER AND COOLER TEMPERATURES RETURNING FOR
MONDAY.
AVIATION /22Z 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...MLB/CL
AVIATION...MILCAREK
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