404
FXUS61 KPBZ 220150
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
950 PM EDT SUN JUN 21 2026
WHAT HAS CHANGED
RAINFALL TOTALS FROM TONIGHT THROUGH MONDAY NIGHT HAVE TRENDED
A BIT LOWER, AND UNCERTAINTY REMAINS ON WHERE THE AXIS OF
HEAVIEST RAINFALL MAY SET UP. ISOLATED INSTANCES OF FLOODING
AND/OR SEVERE THUNDERSTORMS REMAIN MOST LIKELY TO THE SOUTHEAST
OF PITTSBURGH.
KEY MESSAGES
1) RAIN CHANCES RETURN TONIGHT AND MONDAY. THERE IS HIGH
CONFIDENCE IN A SOAKING RAINFALL, BUT LOW CONFIDENCE IN THE
THREAT OF FLOODING.
2) DRY CONDITIONS MID-WEEK AND POSSIBLE WARM-UP NEXT WEEKEND.
DISCUSSION
KEY MESSAGE 1...
THE SURFACE LOW SLOWLY RIDES UP THE OHIO VALLEY TONIGHT THROUGH
MONDAY, LIKELY CROSSING INTO CENTRAL PENNSYLVANIA AROUND 00Z
TUESDAY. MODELS HAVE AGAIN BEGAN TO SHOW THE WARM FRONT PUSHING
NORTH BY MIDDAY WHICH WOULD LEAVE WESTERN PA AND NORTHERN WV IN
THE WARM SECTOR FOR MOST OF THE AFTERNOON BEFORE THE COLD FRONT
MOVES THROUGH. THIS WOULD HAVE IMPLICATIONS FOR SEVERE WEATHER
POTENTIAL MONDAY EVENING DEPENDING ON CLOUD BREAKS AND SURFACE
HEATING BETWEEN SHOWERS/STORMS. SPC MAINTAINS A MARGINAL (LEVEL
1 OF 5) RISK FOR NORTHERN WV (EXCLUDING THE PANHANDLE) AND A
COUPLE OF COUNTIES IN SOUTHWESTERN PA AND ADDED A SLIGHT (LEVEL
2 OF 5) RISK IN TUCKER COUNTY. LOW-LEVEL FLOW AND 0-1KM WIND
SHEAR OF 30-40 KNOTS CREATE SOME IMPRESSIVE- LOOKING HODOGRAPHS,
ALTHOUGH WHATEVER MEAGER CAPE THERE IS AT THAT TIME IS LIKELY
TO BE ELEVATED. THIS WILL STILL NEED TO BE MONITORED, AS ANY
SURFACE-BASED BUOYANCY DEVELOPING EARLIER THAN ANTICIPATED COULD
RESULT IN AN ISOLATED TORNADO THREAT. WHILE BUOYANCY MAY
IMPROVE DURING THE MIDDAY AND AFTERNOON HOURS, VEERING LOW-LEVEL
FLOW LEADS TO MORE UNIDIRECTIONAL HODOGRAPHS DURING PEAK
HEATING, MAKING DAMAGING WIND GUSTS THE MOST LIKELY ISOLATED
SEVERE THREAT BY THAT TIME.
PRECIPITABLE WATER STILL SURGES INTO THE 1.5 TO 1.7 INCH RANGE PER
HREF/REFS. THE COMPONENT MODELS OF THESE ENSEMBLES ARE A BIT
INCONSISTENT AS TO WHERE THE HEAVIEST BAND OF PRECIPITATION IS
LIKELY TO OCCUR. WITH THE EVENT NOW IN THE NEXT 48 HOURS, HEAVIER
PRECIPITATION TOTALS SEEM MORE LIKELY TO BE CONFINED MOSTLY TO AREAS
SOUTH OF I-70, WHERE 90TH PERCENTILE RAINFALL TOTALS EXCEEDING 1.5
INCHES ARE MOST PREVALENT IN BOTH ENSEMBLES. ANY FLOODING THREAT MAY
BE TIED TO SMALLER-SCALE STORM TRAINING NEAR THE BOUNDARY. WPC
MAINTAINS A SLIGHT (LEVEL 2 OF 4) RISK FOR EXCESSIVE RAINFALL
SOUTHEAST OF A HLG/AGC/IDI LINE.
COVERAGE OF SHOWERS/STORMS WILL DECREASE FROM WEST TO EAST MONDAY
NIGHT WITH THE DEPARTURE OF THE SURFACE LOW, SETTING UP A DRIER
PATTERN AND NEAR-TO-BELOW NORMAL TEMPERATURES FOR THE MIDDLE OF THE
WEEK.
KEY MESSAGE 2...
AFTER THE RAIN ON MONDAY, A HIGH PRESSURE SYSTEM WILL MOVE IN
THE AREA. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES IN
THE MID TO UPPER 70S TUESDAY AND WEDNESDAY. BY THURSDAY, A WEAK
DISTURBANCE WILL BRING THE CHANCE FOR SCATTERED SHOWERS AND
THUNDERSTORMS.
BY SATURDAY, WARMING TREND WILL BEGIN AS AN UPPER LEVEL RIDGE
BUILDS INTO THE AREA. THE PROBABILITY FOR TEMPERATURES IN THE
UPPER 80S TO 90 WILL GRADUALLY INCREASE INTO THE START OF THE
FOLLOWING WEEK.
AVIATION /00Z MONDAY THROUGH FRIDAY/
CIRRUS BLOWOFF FROM UPSTREAM STORMS AND MID-LEVEL JET WILL
CONTINUE TO INVADE THIS EVENING, PROVIDING A DENSE BKN-OVC LAYER
AT 12-15 KFT THAT WILL SLOWLY LOWER WITH TIME AS WARM ADVECTION
CONTINUES TO PROMOTE SATURATION FROM ABOVE.
WARM ADVECTION AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM IS
LIKELY TO INVIGORATE BROAD COVERAGE OF LIGHT RAIN/SHOWERS LATE
TONIGHT. MUCH OF THIS PRECIPITATION WILL GO TO SATURATE THE
COLUMN, SO VERY LITTLE ACCUMULATION IS ANTICIPATED PRIOR TO
SUNRISE. THE MAIN RESULT WILL BE LOWERING CIG HEIGHTS TOWARD
MORNING, WITH A POTENTIAL DIP TO MVFR IN THE 22/1000-22/1300 UTC
RANGE WHEN SHOWERS MAY REACH THEIR PEAK INTENSITY. ALTHOUGH
THERE IS A LOW CHANCE OF THUNDER, ANY DEEPER CONVECTION SHOULD
REMAIN SHORT-LIVED.
AFTER THESE EARLY MORNING SHOWERS, A LULL IN PRECIPITATION IS
MOST LIKELY, PROVIDING A MODEST OPPORTUNITY FOR ATMOSPHERIC
RECOVERY. GIVEN THE LACK OF CAPPING INVERSION, ANY MEAGER
HEATING WILL QUICKLY INVIGORATE CIGS IN THE MVFR RANGE BY
22/1500-22/1600 UTC, AND SHOWERS QUICKLY THEREAFTER. THE DEGREE
OF DESTABILIZATION REMAINS HIGHLY IN QUESTION, AND POTENTIAL FOR
AFTERNOON THUNDER IS THUS UNCERTAIN. THEREFORE, PROB30 WILL BE
USED TO COVER THE TIMING OF POTENTIAL THUNDER DEVELOPMENT ATTM.
STRONG WIND ALOFT MAY LEAD TO AREAS OF WIND SHEAR, BUT WITH
CONVECTION AROUND, HAVE OPTED TO OMIT THE MENTION IN THE TAFS
FOR CLARITY. WILL RE-EVALUATE BEFORE THE 0300 UTC TAF UPDATE.
OUTLOOK...
FOG IS LIKELY MON NIGHT IN THE WAKE OF WIDESPREAD SHOWERS. VFR
CONDITIONS ARE LIKELY TO RETURN TUESDAY AFTER THE MORNING FOG.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...34/CL/LUPO
AVIATION...KRAMAR
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