Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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314 FXUS61 KPBZ 232357 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 757 PM EDT Thu Jul 23 2026 .WHAT HAS CHANGED... No major chances to the forecast in the near-term. Severe weather potential continues to be late Sunday into Tuesday. && .KEY MESSAGES... 1) Severe weather and heavy rainfall possible Sunday through Tuesday with a pattern shift && .DISCUSSION... KEY MESSAGE 1... Confidence remains high that dry and cool conditions will prevail through at least Saturday afternoon under high pressure and northwest flow. Temperatures will return to seasonal averages, so the 40s we saw this morning across parts of the region won`t last long. There is the potential for a few isolated pop up showers and thunderstorms Saturday afternoon on the leading edge of warm, moist advection as flow shifts from the southwest. Brief periods of lightning would be the main hazard. The threat for severe thunderstorms is expected to return early next week as a ridge axis strengthens over the central CONUS and a large-scale low intensifies north of Ontario. The evolving synoptic pattern favors upstream mesoscale convective system (MCS) development upstream over the northern Great Lakes, with subsequent propagation into the region or redevelopment along remnant outflow boundaries and residual convective features. 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. However, the potential for large hail may be limited by a warm freezing level (above 14kft), prompting the melting of hail stones. NCAR Machine-learning guidance continues to indicate a 5-30% probability of severe thunderstorms from Sunday through Tuesday across the Ohio River Valley. Colorado State University (CSU) machine learning has 5-15% chance of excessive rainfall (flash flooding) Sunday and Monday and shifts the potential 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 /00Z FRIDAY THROUGH TUESDAY/... VFR conditions are expected through the TAF period with the exception of a few spots of fog tomorrow morning which will mainly be the river valleys. Expect mainly clear skies through the overnight and tomorrow. Light and variable winds are expected through the period. 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/McMullen AVIATION...Shallenberger