


Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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203 FXUS61 KPBZ 020008 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 808 PM EDT Mon Sep 1 2025 .SYNOPSIS... Seasonable and mostly dry conditions prevail through midweek. Widespread rain chances return Thursday with the approach and passage of a cold front. Gusty winds are also possible with the front passage Thursday afternoon. Cooler and relatively drier weather returns late week. && .NEAR TERM /THROUGH TUESDAY/... KEY MESSAGES: - Seasonable and dry for Labor Day - Patchy river valley fog overnight --------------------------------------------------------------- Another beautiful day is underway to mark the first day of meteorological fall. High pressure with subsidence aloft will keep the area dry with seasonable temperatures. A slight uptick in low-level moisture courtesy of eastern flow off the Atlantic will allow more expansive fair weather cumulus this afternoon, though surface dewpoints remain mostly in the 40s across the area, making for very comfortable conditions for Labor Day. Tonight, cumulus will fade with sunset and loss of mixing, leaving calm and mostly clear conditions overnight. This should promote efficient radiational cooling with lows 5-10 degrees below normal. Cool air above still warm water may allow for patchy river valley fog as well, primarily along the Allegheny headwaters. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/... KEY MESSAGES: - Dry and seasonable again Tuesday - Isolated showers possible south of I-70 Wednesday afternoon ---------------------------------------------------------------- Very little change is expected on Tuesday as surface low pressure lingers across the region, and upper low pressure meanders overhead. Temperatures will again be seasonable with sunshine marred only by daytime fair weather cumulus. Humidity remains low, making for another very pleasant early September day. The upper low will begin to lift out of the area and into the Canadian maritimes Tuesday night while surface wind becomes a bit more southerly. This will aid in better moisture return on Wednesday, increasing humidity a bit and boosting afternoon highs a few degrees above average. A weak shortwave will cross the region by Wednesday afternoon, but will likely arrive before better moisture from the south. NBM PoPs show slight chances for rain Wednesday afternoon from ZZV to MGW, but any showers are likely to remain isolated as deeper moisture remains much farther south across the Tennessee Valley. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... KEY MESSAGES: - Showers, thunderstorms, and gusty winds are expected with a cold front passage on Thursday - Cooler and generally dry weather returns in the weekend ------------------------------------------------------------------- Better moisture arrives Wednesday night into Thursday with increasing southerly flow. This should allow increasing cloud cover and shower chances by early Thursday morning. Cloud cover and rain chance will keep low temperatures near normal for the first time in a while. Better chances of more widespread rain will return Thursday morning/afternoon ahead of the cold front. Some variability remains with the strength of the trough, stronger likely yielding more plentiful rainfall, and weaker keeping most totals below 0.5". With strong forcing, quick frontal movement, and deep mixing below a 50kt 500mb jet, gusty winds of 30-40 mph will be possible Thursday afternoon ahead of and along the front. NCAR ML convective forecasts broadbrush low-end severe potential along the front, but generally keep better chances east of our area. Any severe threat will need to be monitored, especially as we come within CAM ranges. Friday, the closed low may wobble around with some solutions placing the low over Ontario, and other along the southern shore of the Hudson Bay. Again, a more southerly and/or stronger position would mean cooler temperatures, generally more clouds (or even showers) chances on shortwave spokes, and generally gustier winds. A more northern and weaker track would mean the opposite. This keeps next weekends temperature spread anywhere from the upper 60s to mid 70s for highs, daytime wind spread anywhere from 25mph to 35mph maximum gusts, and rain chances anywhere from 0% to 30%. Most ensembles see a warming trend back to near normal temperatures as we head into the middle of next week, with only the exact timing of the warmup the main axis of uncertainty depending on the departure of the eastern trough. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... High confidence VFR conditions continuing through the TAF period under high pressure. A dry boundary layer and plenty of subsidence will make for a continued period of mid and upper level cloud cover for tomorrow as well. Wind settles becoming light to variable tonight. Winds will stay variable through the day tomorrow as well. Some river valley fog is again possible early Tuesday morning but, similar to Monday morning, probability of impacts to terminals is low. .OUTLOOK.... VFR conditions continue through Wednesday. The passage of a cold front on Thursday will bring rain with the possibility of isolated thunderstorms. The boundary is also forecast to bring a strong vertical wind profile, which increases the chance for low-level wind shear and/or wind gusts. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Rackley/Milcarek NEAR TERM...Rackley SHORT TERM...Rackley/Milcarek LONG TERM...Rackley/Milcarek AVIATION...Shallenberger