892
FXUS61 KPBZ 222358
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
758 PM EDT FRI MAY 22 2026
WHAT HAS CHANGED
ALONG WITH THE ISSUED FLOOD WATCH, THERE IS A LOW PROBABILITY
FOR CONVECTIVE SHOWERS SATURDAY AFTERNOON TO DEVELOP BRIEF
TORNADOES.
KEY MESSAGES
1) FLOOD WATCH TODAY INTO TOMORROW FOR HEAVY RAINFALL AMOUNTS
2) LOW PROBABILITY FOR A BRIEF TORNADO FAVORING SOUTHEAST OHIO
SATURDAY AFTERNOON
2) SHOWERS/THUNDERSTORMS CHANCES CONTINUE INTO EARLY NEXT WEEK
3) WARMER BY THE MIDDLE OF NEXT WEEK
DISCUSSION
KEY MESSAGE 1...
MODERATE TO HEAVY RAINFALL IS EXPECTED LATE THIS EVENING INTO
EARLY TOMORROW MORNING, MAINLY BETWEEN 8PM AND 6AM AS A LOW
PRESSURE SYSTEM ADVANCES INTO THE REGION FROM THE SOUTH. THE
REASON BEHIND THESE HEAVIER RAINFALL AMOUNTS IS STRONGER
SOUTHWEST OVER SOUTHERN OHIO, ENHANCING FRONTOGENESIS. PROBABILITY
OF EXCEEDING 2 INCHES OF RAIN IN THE NEXT 24 HOURS IS ELEVATED
(ABOVE 70%) FOR PORTIONS OF EASTERN OHIO AND WESTERN
PENNSYLVANIA. THEREFORE, A FLOOD WATCH WAS ISSUED. ROADWAYS
NEAR CREEKS AND STREAMS WILL LIKELY BE THE AREAS OF CONCERN WHEN
IT COMES TO FLOODING.
WITH HIGH-RESOLUTION MODELS DEPICTING SATURATED TEMPERATURE PROFILES
(PWAT VALUES NEAR 1.50 INCHES), INSTABILITY WILL BE VERY LOW.
THEREFORE, THE PROBABILITY OF THUNDERSTORMS IS CONSIDERED LOW AS
WELL (LESS THAN 10%) FOR THE NEXT 24 HOURS. IF A THUNDERSTORM
EVOLVES, IT WOULD MOST LIKELY BE SATURDAY EVENING AS MID-LVL DRY
AIR ADVANCES INTO SOUTH CENTRAL OHIO. LIGHTNING WOULD BE THE
MAIN THREAT.
KEY MESSAGE 2...
AS PART OF THE FLOOD THREAT, POSITIONING OF THE SURFACE LOW
EVENTUALLY IN NORTH CENTRAL OH BY SATURDAY AFTERNOON FAVORS A
CONVERGENCE ZONE FOR CONVECTIVE INITIATION ACROSS SOUTHEAST OH
(AROUND I-77 CORRIDOR). ASSUMING ENOUGH DESTABILIZATION OCCURS
WITH HEATING AMID BREAKS IN CLOUDS, HREF FAVORS CAPE VALUES
APPROACHING 1000 J/KG (AND NEAR 150 J/KG 0-3KM CAPE) WITH
100-200 0-1KM SRH VALUES (BUT WEAK 0-6KM SHEAR) AND LOW LCLS.
THESE FACTORS LEND TO A LOW PROBABILITY TORNADIC THREAT,
HIGHLIGHTED BY THE SPC MARGINAL RISK, WHERE MINI SURGES
(SPECIFICALLY, EASTWARD SURGES) IN A CONVECTIVE LINE DEVELOP A
SHORT-LIVED TORNADO, EVEN IF NO LIGHTNING COMES TO FRUITION.
THE MAIN WINDOW FAVORS 3PM-8PM SATURDAY BEFORE LOSS OF
LIFT/HEATING ERODE THREAT POTENTIAL.
KEY MESSAGE 3...
SHOWERS ARE LIKELY SUNDAY NIGHT AS THE SHORTWAVE TROUGH CROSSES
THE UPPER OHIO VALLEY REGION. A THUNDERSTORM IS POSSIBLE THOUGH
INSTABILITY IS EXPECTED TO BE LIMITED. SHOWER/STORM CHANCES ARE
EXPECTED TO DECREASE FROM NW-SE THROUGH THE DAY MONDAY AS THE
UPPER SUPPORT EXITS, AND A SURFACE TROUGH SETS UP ACROSS THE
MID ATLANTIC TO LOWER OHIO VALLEY REGION. ANOTHER CROSSING
SHORTWAVE WILL RETURN SHOWER AND THUNDERSTORMS CHANCES FOR
TUESDAY, MAINLY SOUTH OF I-80.
KEY MESSAGE 4...
A WARMING TREND IS EXPECTED THROUGH MID TO LATE WEEK. A WEAK
TROUGH COULD BRING A FEW SHOWERS/STORMS WEDNESDAY, THOUGH
BUILDING HIGH PRESSURE SHOULD RESULT IN MAINLY DRY WEATHER BY
LATE WEEK.
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
RAIN IS OVERSPREADING THE REGION AT THIS TIME. ALONG WITH IT,
DROPS TO IFR ARE NOTED ACROSS OH AND ARE ENCROACHING ON OUR
WESTERN PA PORTS AT THIS TIME. A STOUT DOWNSLOPE EASTERLY WIND
IS HELPING TO KEEP SOME HIGHER CIGS CLOSER TO THE RIDGES AND
THESE ARE REACHING AS FAR AS AGC AND PIT. HREF PROBABILITIES FOR
MVFR CIGS SHOW THIS POCKET DECENTLY WELL. THERE COULD BE A
COUPLE OF HOURS OF FLUCTUATION IN CIGS AT PIT, MORE AT AGC AND
THEN SOME QUESTION AS TO WHETHER MGW/LBE DIP INTO MVFR AND FOR
HOW LONG. FOR NOW THE CURRENT TAFS REPRESENT A BIT MORE
PESSIMISTIC FORECAST FOR CIGS BUT THOSE 4 PORTS COULD SEE LONGER
PERIODS OF HIGHER CIGS.
THE HEAVIEST RAINFALL MOVES FROM SOUTH TO NORTH OVERNIGHT
LARGELY FROM 02-10Z. WIDESPREAD COVERAGE OF RAIN ENDS FROM
SOUTHWEST TO NORTHEAST BEGINNING FOR ZZV CLOSER TO 09Z SATURDAY.
AFTER THIS, SHOWERS BECOME MORE SCATTERED IN NATURE THROUGH THE
REMAINDER OF THE DAY, WITH THE POSSIBILITY THAT THERE COULD BE
SOME STRETCHES OF DRY OR VCSH ACTIVITY IN THE AFTERNOON.
CEILING RESTRICTIONS WILL MAKE LITTLE IMPROVEMENT THROUGH
SATURDAY. SHOWERS CAN BECOME A LITTLE MORE WIDESPREAD WITH
EMBEDDED THUNDERSTORMS IN THE WARM SECTOR TOMORROW AFTERNOON AND
EVENING.
SOUTHEASTERLY WINDS WILL REMAIN SUSTAINED BETWEEN 08-12 KTS
OVERNIGHT AND COULD REMAIN GUSTY WITH FLUCTUATIONS IN GUSTS.
WINDS CAN BE SUSTAINED BETWEEN 10-15 KTS TOMORROW WITH GUSTS
BETWEEN 20-30 KTS. THE HIGHEST GUSTS WILL LIKELY BE OBSERVED AT
LBE WITH THE ADDED HELP OF DOWNSLOPE EFFECTS.
OUTLOOK...
WIDESPREAD CEILING RESTRICTIONS WILL CONTINUE LATER SATURDAY
INTO THE OVERNIGHT WITH ISOLATED RAIN CHANCE. SOME IMPROVEMENT
IS POSSIBLE SUNDAY UNTIL A COLD FRONT APPROACHES LATER IN THE
DAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR PAZ020-021-029-031.
OH...FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR OHZ039>041-048>050-
057>059-068-069.
WV...FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR WVZ001>004-012.
DISCUSSION...HEFFERAN/FRAZIER
AVIATION...AK
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