Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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714 FXUS61 KPBZ 260600 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 200 AM EDT Sun Jul 26 2026 .WHAT HAS CHANGED... Thunderstorm chances have decreased today. The severe weather potential continues Monday into Tuesday. && .KEY MESSAGES... 1) Isolated thunderstorms today 2) Shower and thunderstorms, and a severe weather potential, returns Monday into Tuesday && .DISCUSSION... KEY MESSAGE 1... A crossing weak shortwave trough, and convergence along a lake breeze boundary, should result in isolated to scattered showers and thunderstorms mainly north of Pittsburgh this afternoon and early evening. Capping warmth aloft should preclude more significant chances for thunderstorms toward PIT and points to the south. Entrainment of dry air aloft should also limit updraft development, with ML CAPE reaching 500-1000 j/kg this afternoon north of PIT. If updrafts are able to become organized, then gusty wind will be possible with an enhanced DCAPE due to the dry air aloft. Otherwise, after some morning fog, partly cloudy skies are expected today, with highs near average. KEY MESSAGE 2... Uncertainty in the details still exist in the forecast for Monday into Tuesday. An MCS is expected to develop tonight across the Upper Midwest, moving southward overnight. This activity is currently expected to stay west of the forecast area. Recent CAMs have trended toward less convection on Monday. Still expect scattered thunderstorms to develop through the day with building diurnal instability. ML CAPE is progged to range from 1500-2500 j/kg. Expect scattered convection to develop as convective temperatures are reached. More focused areas of thunderstorms will also be possible on any outflow boundaries from upstream convection. Some increase in 0-6km shear is expected (30kt), with some dry mid level air in place. This should result in a damaging wind potential in storms that become organized. Large hail is also possible, along with isolated tornadoes as wind increasingly veers with height. Recent CAMS also indicate a potential MCS Monday night into Tuesday morning, developing over the Great Lakes region and tracking SEWD across portions of the Upper Ohio Valley region. This is in advance of an approaching shortwave trough and surface cold front. While instability should wane somewhat Monday night, a severe storm potential would still be possible with an organized MCS. Localized flash flooding will be possible as well, especially if or where any multiple rounds of storms occur. Uncertainty still remains in the exact development, timing, and tracks of any MCSs, with a low confidence predictability until closer to the event. The trough and surface cold front should cross the Upper Ohio Valley region on Tuesday, with continued showers and thunderstorms. The severe potential will depend on the extent of morning convection and cloud cover, though the latest ML guidance begins to shift the best severe potential sewd through the day. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... Patchy MVFR fog is expected at fog prone airports overnight with calm wind, clear skies, and low level moisture in place. LIFR fog is expected at DUJ, where rain occurred on Saturday. The fog should gradually mix out and dissipate after sunrise. A weak shortwave trough, and convergence along a lake breeze, could result in isolated showers/thunderstorms near and north of a PHD-FKL-DUJ line this afternoon/early evening, though limited coverage precludes a TAF mention at this time. Otherwise, VFR is expected with scattered diurnal CU today, and increasing mid/high clouds tonight. Outlook... Thunderstorm chances increase Monday into Tuesday with the approach and passage of a cold front. A few storms could be severe. Low shower/storm chances continue Wednesday with another passing wave, before VFR returns Thursday under building high pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...WM AVIATION...WM