Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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227 FXUS61 KPBZ 270330 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1130 PM EDT Wed Jun 26 2024 .SYNOPSIS... Dry weather resumes today with shower and thunderstorm chances returning for the weekend. Near normal temperatures today will rise into the weekend. && .NEAR TERM /THROUGH THURSDAY NIGHT/... KEY MESSAGES: - Fog development expected this morning. - Dry weather resumes today with near normal temperatures. ------------------------------------------------------------------- A moist, cool airmass remains after recent showers and thunderstorms across the region, and with relatively light wind and temps approaching saturation, patchy fog development is expected overnight (especially for river valleys absent of low level cloud coverage). Any stratus or fog should erode by mid- morning, with mainly upper- level clouds lingering thru the day. Cool, dry northwest flow will develop as high pressure builds in from the northwest with increasing subsidence diminishes lingering stratocu through the morning, which should eventually turn into scattered afternoon cumulus. Cold advection and partial cloud cover will result in more seasonable afternoon temperature while post- frontal mixing may support NW wind gusts around 20 mph. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... KEY MESSAGES: - Dry weather continues. - Temperature rises above normal again Friday. ------------------------------------------------------------------- The surface high will shift over New England by Friday as heights aloft rise ahead of the next upper level shortwave trough. Positioning of the high will support weak warm, moist advection amid mostly clear skies to raise area temperature about 5 degrees above the daily average. Broad ascent may increase mid to high level clouds and even low probability showers Friday night as weak perturbations ahead of the main upper level trough axis. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... KEY MESSAGES: - Shower and thunderstorm chances return Saturday into Sunday with the next low pressure system. - Low probabilities exist for a damaging wind and flooding threat with these thunderstorms. ------------------------------------------------------------------- Broad ascent within warm, moist southwesterly flow ahead of the main upper level trough axis will support increasing shower and thunderstorm probabilities starting early Saturday morning. Arrival of a more notable embedded shortwave and the surface cold front Saturday afternoon and evening is likely to help concentrate convective activity (currently favoring NW PA) and spreading it southeast through Sunday morning. Variation in storm timing and environment remains large due to differences in upper trough depth/timing as well as convective evolution prior to its (and cold fronts) arrival. Latest analysis suggests a low probability risk for damaging wind (mean values currently show 30-40kts of 0-6km shear) and localized flooding (tall-skinny CAPE values around 1500 J/kg with PWATs approaching daily maxima). Will mention threat in HWO and monitor evolving forecasts for this period. Dry weather and seasonable temperature is likely by late Sunday into Monday as the upper trough axis moves east and high pressure builds in from the western Great Lakes. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... Storms continue along a line from near IDI to MGW, advancing ewd. In the wake of these storms, residual showers will last an hour or two before quickly eroding. The cool, moist airmass in the wake of storms is likely (70-80%) to support fog development overnight and possibly low cigs, with potential for LIFR vsby early Thu morning. Rapid improvement to VFR is expected by mid-morning after any morning restrictions. .Outlook... VFR is expected through Fri amid high pressure. Restrictions are possible Fri night with a crossing warm front. Restrictions are likely Sat and Sat night with showers and thunderstorms ahead of and along a crossing cold front. VFR returns Sun under high pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...88 NEAR TERM...88 SHORT TERM...88 LONG TERM...Frazier AVIATION...Kramar/WM/Hefferan