698
FXUS61 KPBZ 221641
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1241 PM EDT WED JUL 22 2026
WHAT HAS CHANGED
REMOVED KEY MESSAGE ON LINGERING HYDROLOGY IMPACTS.
KEY MESSAGES
1) SEVERE WEATHER AND HEAVY RAINFALL POSSIBLE SUNDAY THROUGH
TUESDAY
DISCUSSION
KEY MESSAGE 1...
THE THREAT FOR SEVERE THUNDERSTORMS COULD RETURN EARLY NEXT WEEK
AS A STRONG UPPER HIGH ANCHORS OVER THE FOUR CORNER STATES AND
NORTHWEST FLOW BECOMES ESTABLISHED FROM THE NORTHERN PLAINS INTO
THE NORTHEAST STATES. THIS FAST NORTHWEST FLOW PATTERN FAVORS
KEEPING DECENT AMOUNTS OF DEEP LAYER VERTICAL WIND SHEAR AND
POTENTIALLY STEEP LAPSE RATES AT MID LEVELS IN PLAY. THERE IS A
TYPICAL AMOUNT OF UNCERTAINTY/DIFFERENCES IN LOCATION AND
TIMING OF SHORT WAVE TROUGHS TOPPING THE UPPER RIDGE AND HEADING
SOUTHEAST ACROSS THE GREAT LAKES AND OHIO VALLEY AREA.
LONG-RANGE GUIDANCE SUGGESTS ONE OR MORE MESOSCALE CONVECTIVE
SYSTEMS (MCSS) MAY DEVELOP OVER THE MIDWEST BEFORE TRACKING INTO
THE OHIO RIVER VALLEY. FORECAST SOUNDINGS INDICATE AN
ENVIRONMENT CAPABLE OF SUPPORTING ALL SEVERE WEATHER HAZARDS,
INCLUDING LARGE HAIL, DAMAGING WIND GUSTS, TORNADOES, AND HEAVY
RAINFALL. MACHINE LEARNING GUIDANCE CURRENTLY INDICATES A 5-30%
PROBABILITY OF SEVERE THUNDERSTORMS FROM SUNDAY THROUGH TUESDAY
ACROSS THE OHIO RIVER VALLEY. CSU MACHINE LEARNING HAS 5-10%
CHANCE OF EXCESSIVE RAINFALL SUNDAY AND MONDAY AND SHIFTS THINGS
MOSTLY SOUTH OF AREA BY TUESDAY. 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.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
MVFR, WITH LOCALIZED IFR, STRATOCU IS EXPECTED TO CONTINUE THIS
MORNING AS A COLD FRONT COMPLETES ITS PASSAGE. MIXING AND DRY
ADVECTION SHOULD RESULT IN CIGS RETURNING TO VFR LEVELS BY EARLY
AFTERNOON. BUILDING HIGH PRESSURE SHOULD THEN MAINTAIN VFR
CONDITIONS THROUGH THURSDAY, OUTSIDE OF ANY EARLY MORNING RIVER
VALLEY FOG.
OUTLOOK...
VFR IS EXPECTED THROUGH SATURDAY UNDER HIGH PRESSURE. SHOWER AND
THUNDERSTORM CHANCES RETURN ON SUNDAY WITH AN APPROACHING COLD
FRONT.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CRAVEN
AVIATION...WM
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