Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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396 FXUS61 KPBZ 301135 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 735 AM EDT Wed Sep 30 2026 .WHAT HAS CHANGED... Upcoming weekend precipitation chances have decreased, otherwise no major changes were made to the latest forecast. && .KEY MESSAGES... 1) Mainly dry through Thursday, before shower chances return with a Friday cold front 2) Cooler with periodic shower chances for the upcoming weekend && .DISCUSSION... KEY MESSAGE 1... The upper level pattern will continue to feature a trough over the central CONUS as the ridge over the east remains in place but begins to weaken as it shifts to the east-southeast with time. The now closed low at the base of the trough over the central plains now opens and ejects a shortwave into the Lower Ohio Valley. This will bring a cold front to the region entering the Upper OH Valley by Thursday night. A weaker piece of energy may travel the northern area of the ridge and bring some precip to the northern counties on Wednesday night. Otherwise, the main focus will be on the front attempting to move through the region from the northwest. This will track east through the overnight and into the day on Friday. The rainfall threat will not be anything to be concern over since we have been dry over the past week. The NBM suggest rainfall amounts will not be too concerning as the probabilities of exceeding only 0.50" will be between 40% and 60% across the area. As well, the thunderstorm threat on Thursday night and into Friday will be minimal as even the NBM gives a 10% chance of even reaching 500 J/Kg of SB CAPE. Even the prob thunder for this period is only between 10% to 15%. Thus, nothing is worth mentioning in the HWO at this time. KEY MESSAGE 2... Broad upper troughing is progged to set up across the NE CONUS through the upcoming weekend. Saturday should be mainly dry and cooler as surface high pressure builds in from the north, though a crossing southern stream wave should result in shower chances mainly south of I-70. Shower chances then increase on Sunday as a northern stream shortwave rotates through the broad upper trough. Cooler temperatures are expected, with highs just below seasonable levels. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... Fog, more valley-based to the south of PIT and a bit more widespread to the north, is producing LIFR/VLIFR conditions at several terminals at 12Z. Ongoing PBZ 12Z sounding shows that the fog is quite shallow, and it should burn off by 14Z even as a veil of high clouds builds in. Once the fog dissipates, VFR conditions are forecast for the balance of the TAF period, with a light southerly wind. Given the lingering cloud cover, fog should be less of an issue tonight. However, a weak shortwave tracking to the north of PIT may produce a few rain showers at FKL/DUJ after midnight. Outlook... Restrictions in showers are likely with a Friday cold front. Restrictions are possible south of I-70 Saturday, and across the remainder of the area Sunday, with crossing disturbances. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Shallenberger AVIATION...CL