Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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625 FXUS61 KPBZ 120633 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 233 AM EDT Wed Aug 12 2026 .WHAT HAS CHANGED... The heavy rainfall/flooding threat is lower for today (with the Flood Watch to be cancelled early), but the chance for isolated damaging wind/large hail events is a bit higher, mainly north of Pittsburgh. && .KEY MESSAGES... 1) Daily chances of showers and thunderstorms continue through Thursday. The flooding threat is lower for today, but may increase for areas south of Pittsburgh on Thursday. Isolated severe storms are possible north of Pittsburgh this afternoon and evening. 2) The next best chance of numerous showers and thunderstorms arrives Sunday. A break in the pattern may follow early next week. && .DISCUSSION... KEY MESSAGE 1... A (thankfully) quiet night is in progress, as the environment is generally stable with no present forcing for ascent. As such, low clouds and fog are developing and should plague the CWA into the post-sunrise hours. The effective outflow boundary/front remains relatively far to the south and west of the region, as a result of the recent parade of thunderstorm complexes. The ongoing convection in eastern IN/western OH is evidence of this boundary`s position. Expect this general regime to continue through today and tonight, as HREF/CAMs continue to show the bulk of convective activity more closely tied to this boundary. Still, some scattered showers and storms are possible during the later afternoon and evening, once weak capping is overcome in an environment with around 1000 J/kg of MLCAPE. North of Pittsburgh, shear of 30-35 knots may support some storm organization, supporting isolated damaging wind and hail threats. Any such activity should mostly fade away during the later evening hours. The heavy rain threat appears lower today, given the further west favored track for convective complexes and relatively elongated hodographs promoting faster storm motion. HREF/REFS 90th percentile QPF through 8 PM Thursday is an inch or lower for most areas, including the area of the current Flood Watch that expires at 8 AM. As such, this watch will likely be cancelled a few hours early. For Thursday, severe chances appear to once again be limited, with sufficient shear/instability for isolated damaging wind/hail threats at most. The favored zone for convective complexes should remain west of the area, but the richer reservoir of moisture/instability may edge closer, resulting in higher rain chances to the south of Pittsburgh. This will need to be monitored - if the heavy rain threat in this area increases, a new Flood Watch may be necessary. KEY MESSAGE 2... Thereafter the WNW flow pattern continues with nearly daily thunderstorm chances, although a break may be seen Saturday. Sunday still appears to have the higher probabilities of a concentrated area of precipitation given the approach of a cold front. Non-zero severe weather and heavy rainfall threats will persist. A break in the pattern may finally arrive after that front early next week as surface high pressure makes a more definitive push into the Upper Ohio Valley. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... A stable environment is in place across the region, with a welcome break from convection. With low-level moisture in place, IFR to LIFR stratus/fog has already developed at several terminals and is expected to become a bit more widespread as sunrise approaches. Ceilings should lift to MVFR by late morning, and transition into a CU/stratocu layer and return to VFR levels by afternoon. Models continue to show a weak shortwave tracking across the eastern Great Lakes/Upper Ohio Valley during the late afternoon and early evening. Scattered showers and thunderstorms may be the result. Terminals north of PIT (mainly FKL/DUJ) may be slightly more favored for impacts, but confidence in exact timing and placement remains relatively low, and thus continued with PROB30 mentions at all TAF sites. Outlook... Patchy morning fog and stratus is possible Thursday morning. A wave of low pressure tracking along a stationary front will increase shower/thunderstorm chances Thursday into Thursday night. VFR returns Friday night through Saturday night under high pressure. Restriction potential returns with shower and thunderstorm chances on Sunday with the approach of a cold front. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...CL AVIATION...CL