938
FXUS61 KPBZ 240833
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
433 AM EDT FRI JUL 24 2026
WHAT HAS CHANGED
MINOR UPDATES TO KEY MESSAGE #1
KEY MESSAGES
1) A FEW STRONG TO SEVERE STORMS COULD OCCUR ON SUNDAY IN
EASTERN OHIO; WIDESPREAD SEVERE WEATHER POTENTIAL RETURNS MONDAY
AND TUESDAY
DISCUSSION
KEY MESSAGE 1...
DRY AND QUIET WEATHER WILL PREVAIL THROUGH SATURDAY MORNING
UNDER HIGH PRESSURE. A WEAK TROUGH ACROSS WESTERN PENNSYLVANIA
AND SHALLOW INSTABILITY (600-800J/KG OF SURFACE BASED CAPE) MAY
PROMPT ISOLATED SHOWER ACTIVITY BETWEEN 3PM TO 7PM SATURDAY
AFTERNOON. THE POTENTIAL FOR LIGHTING IS LOW BUT NOT ZERO.
UPDRAFTS MAY STRUGGLE TO DEVELOP DUE TO ENTRAINED DRY AIR.
CONFIDENCE IS INCREASING THAT MESOSCALE CONVECTIVE SYSTEMS
(MCSS) WILL DEVELOP OVER THE GREAT LAKES THIS WEEKEND AS HIGH-
RESOLUTION MODEL GUIDANCE CONTINUES TO COME INTO RANGE. FOR
SUNDAY, THE THREAT FOR STRONG TO SEVERE STORMS MAY STAY WEST OF
OUR REGION, MORE-SO IN CENTRAL AND WESTERN OHIO WHERE A MOISTURE
BOUNDARY WILL LIKELY RESIDE. IF THERE IS A STRONG TO SEVERE
THUNDERSTORM, IT MAY OCCUR IN EASTERN OHIO DUE TO REMNANT
OUTFLOW BOUNDARIES OVER LAKE ERIE OR SOUTHERN MICHIGAN ADVANCING
SOUTH.
THE POTENTIAL FOR WIDESPREAD STRONG TO SEVERE STORMS BECOMES
MORE FAVORABLE MONDAY INTO TUESDAY AS THE RIDGE OVER THE
NORTHERN GREAT LAKES WEAKENS, OPENING THE DOOR FOR UPSTREAM MCSS
TO PROPAGATE INTO THE REGION OR THAT REMNANT OUTFLOW BOUNDARIES
OF DECAYING MCSS REDEVELOPMENT DURING PEAK HEATING.
IF A MESOSCALE CONVECTIVE SYSTEMS (MCSS) DOES DEVELOP AND TRACK
INTO OUR REGION, FORECAST SOUNDINGS INDICATE AN ENVIRONMENT
CAPABLE OF SUPPORTING ALL SEVERE WEATHER HAZARDS, INCLUDING
HAIL, DAMAGING WIND GUSTS, TORNADOES, AND HEAVY RAINFALL.
NCAR MACHINE-LEARNING GUIDANCE HAS A 5-10% OF SEVERE WEATHER
OVER OUR REGION ON SUNDAY; 15 TO 45% CHANCE FOR MONDAY AND
TUESDAY.
COLORADO STATE UNIVERSITY (CSU) MACHINE LEARNING HAS
5-15% CHANCE OF EXCESSIVE RAINFALL (FLASH FLOODING) MONDAY INTO
TUESDAY. THE WEATHER PREDICTION CENTER HAS ISSUED "MARGINAL"
(1 OUT OF 4) RISKS FOR BACK-TO-BACK DAYS.
THE EVENTUAL EVOLUTION OF THIS THREAT WILL LARGELY DEPEND ON
THE AMPLITUDE OF THE EASTERN U.S. TROUGH AND THE STRENGTH AND
POSITION OF THE UPPER- LEVEL RIDGE, WHICH WILL INFLUENCE THE
TRACK AND INTENSITY OF ANY MCSS.
THE THREAT FOR SEVERE STORMS AND PRECIPITATION IS EXPECTED TO
REMAIN LOW WEDNESDAY INTO THURSDAY IN THE WAKE OF A DEPARTING
COLD FRONT AND BUILDING HIGH PRESSURE.
AVIATION /07Z FRIDAY THROUGH TUESDAY/
VFR CONDITIONS WILL CONTINUE TO PREVAIL THROUGH THE TAF PERIOD
UNDER HIGH PRESSURE. PATCHY FOG IS EVIDENT ON GOES-19 SATELLITE
IMAGERY. ADVANCING CIRRUS CLOUDS FROM THE WEST MAY LIMIT
ADDITIONAL FOG DEVELOPMENT THROUGH THE EARLY MORNING HOURS BY
REDUCING RADIATIONAL COOLING.
OUTLOOK... VFR IS EXPECTED THROUGH SATURDAY UNDER HIGH
PRESSURE. SHOWER AND THUNDERSTORM CHANCES RETURN ON SUNDAY AND
MONDAY WITH AN APPROACHING COLD FRONT.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...HEFFERAN
AVIATION...HEFFERAN
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