Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
369 FXUS61 KPBZ 010806 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 406 AM EDT Tue Sep 1 2026 .WHAT HAS CHANGED... A slight risk has been added for the forecast area for Tuesday and Tuesday night. A slight risk remains in effect for Wednesday. Heat risk looks to be the greatest on Wednesday but storms and cloud cover complicate that. && .KEY MESSAGES... 1) Additional shower and thunderstorm chances at times through late week, with some possibility for severe storms. 2) Heat and humidity build through mid week && .DISCUSSION... KEY MESSAGE 1... The 500MB ridge over the central CONUS will shift east as northwest flow sets up over the Great Lakes and into the Upper Ohio Valley. This will set up a series of shortwaves to travel southeast over the region the next few days. The timing of the shortwaves over the next few days will be the main issue as hi- res models and ensembles are not handling the setup very well in the timing and placement. There is a conditional potential for severe storms on Tuesday. ML CAPE increases to between 2000 and 3000 J/kg by late afternoon and into the evening but consensus in the models suggests a more overnight threat and MU CAPE aloft suggests a good 2000 to 3000 J/Kg CAPE overnight if the instability can be tapped into during the overnight hours. Wednesday appears to be a day where the threat will be more in the late afternoon and evening. Current indications are the ridge should begin to break down late Wednesday and Thursday, as a shortwave and surface cold front approaching. The potential for severe storms will also increase by Wednesday evening, increasing again on Thursday as convection increases in diurnal heating along the slow moving front. Increasing NW flow aloft should result in increased shear and diurnal instability. The potential continues for severe storms into Thursday. The latest ML guidance indicates the increasing severe potential, especially late Wednesday and Thursday. KEY MESSAGE 2... Rising 500mb heights with the building ridge should result in warmer temperatures each day through mid week, with the heat peaking Wednesday when the ridge is strongest across the Upper Ohio Valley region. Most locations outside of the higher terrain should reach the 85 to 90 degree range today, though there is a continued potential for convection and/or patchy cloud cover which could affect daytime highs. The heat should peak Wednesday, as highs in the upper 80s to lower 90s for most areas. The combination of heat and humidity should result in heat index values in the mid to upper 90s Tuesday and Wednesday. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... A VFR forecast is mainly in effect through the period. Overall, westerly to southwest winds are expected up to 10 knots through the day. Showers and thunderstorms are possible through the day with mainly being isolated. The main threat appears to be in the evening and overnight Tuesday into Tuesday night. Where showers and storms disrupt the terminals, there will be lapses in flight conditions through the period. Have put in PROB30s to account for the continued uncertainty. Locations such as ZZv may miss out on the convection completely. Outlook... Shortwave movement along the northern periphery of the ridge could create short periods through the week where showers/thunderstorms may occur. Due to difficulties modeling these features, timing/coverage of storm potential may be difficult until 6-12 hours before arrival and cause larger- than-normal fluctuations in TAF storm timing. Additionally, storm environments may be conducive to gusty, erratic winds plus heavy downpours that could contribute to restriction development. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Shallenberger AVIATION...Frazier/Shallenberger