Area Forecast Discussion
Issued by NWS Pittsburgh, PA

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924 FXUS61 KPBZ 091722 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 122 PM EDT Wed Jul 9 2025 .SYNOPSIS... A surface front will meander across the region through the week and into the weekend maintaining daily shower and thunderstorm chances. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... KEY MESSAGES: - Stalled boundary along the PA/WV border keeps most convection south of Pittsburgh today. - Daytime highs top out just above normal. --------------------------------------------------------------- Light radar returns move across the area this morning with a weak- mid level wave, but dry sub-cloud layer air is preventing much of this from reaching the ground. Have seen a few reports of light showers, but overall this activity will be unimpactful this morning. Latest surface analysis shows a pseudo-stationary boundary parked along the PA/WV border, which will serve as the focal point for any convective development today once instability increases with diurnal heating. Increased mid and upper level cloud coverage will persist through the period with increased moisture advection ahead of an approaching mid-level shortwave. The cloud coverage that has increased over the course of the night has mitigated any widespread fog development this morning, and do not anticipate the need for any advisories at this time. Models, analogs, and machine learning guidance are all in agreement with minimal strong/severe potential with any convection today. This would be limited to portions of northern West Virginia, where there is better instability/stronger updraft potential, and potential for localized heavy rainfall, but the overall threat is low. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... KEY MESSAGES: - Better coverage of scattered storms Thursday as boundary lifts back north. - Slightly above normal temperatures continue. ---------------------------------------------------------------- Convection fades this evening, with the overnight period largely dry across the region. On Thursday, a crossing shortwave trough will push the aforementioned boundary north again as a warm front, resulting in slightly more diurnal convective coverage. Relatively weak CAPE profiles and relatively low shear suggest a minimal severe threat. Latest MSU-CLP and CIPs guidance does not hint at much potential at all for severe convection or flooding in the period. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... KEY MESSAGES: - Stalled boundary lingers into the weekend at least with continued daily rain chances, currently highest Sunday. - Low rain chances next week as pattern uncertainty increases. - Continued near to above-normal temperature. ------------------------------------------------------------------- On Friday, a wave of low pressure along the boundary may push it further south, keeping higher diurnal shower/storm chances across our southern zones. Precipitable water remains elevated near and south of the boundary, so locally heavy rainfall will remain possible. Mainly diurnal shower and storm chances continue into the weekend, with the best chance for more widespread coverage on Sunday as surface low pressure transitions over the northern Great Lakes and the associated cold front crosses the region. There is some uncertainty in timing of FROPA, so with that, NBM 10th to 90th percentile spreads continue to exceed 10 degrees for most of the region, with possible max values ranging from around 80 to the lower 90s. Severe/flooding potential is non- zero, but on the low end at this time based off latest models, analogs, and machine learning guidance. Uncertainty them propagates into next week. Elevated 500mb heights and zonal flow aloft are most likely, keeping temperatures near to above normal, but differences in disturbances in that flow require low-end PoPs for both Monday and Tuesday. && .AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
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Convective development across northern West Virginia has overachieved this afternoon so far. Impacts to our terminals from this should be tied to only MGW as stratiform rain/more stable nature to the development has shed farther off to the north. So have included a TEMPO down to IFR in TSRA for MGW while this batch passes nearby and the rest of the sites (save perhaps some light rain at LBE) should hold dry with a mid-level cloud deck and light southwest wind. Following sunset, the probability for precipitation decreases. Some fog development is again likely tonight with light to calm wind and elevated surface moisture. Hi res probability favors similar development to Tuesday night, especially where rain falls today, with persistence in a relatively unchanged airmass bringing elevated chances for 1/4SM vis to 50-60% at MGW, LBE, HLG, and ZZV. Other sites are less probable to see restrictions but lesser chances do extend into PIT/AGC. Additional convection is expected on Thursday after 17-18z and will take on a scattered nature. Timing will be difficult to pin down with development potentially off of the lake breeze initially and then cold pools driving further initiation. Any showers/storms could bring brief heavy rainfall and gusty wind. Have included a PROB30 at PIT for now and will continue evaluating as the timeframe becomes included in the rest of the TAF sites. Outlook... A weakly forced but warm/humid environment is favored through the end of the week that will allow for intermittent periods of showers/thunderstorms; confidence is likely to be lower on timing various rounds of precipitation as well as the resultant cig/vis impact they could have during the morning hours. More significant upper level and surface boundary movement appears to arrive over the weekend that will create a more focused and better timed period for convection and restriction development.
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&& .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...88 NEAR TERM...MLB/88 SHORT TERM...88 LONG TERM...88 AVIATION...MLB