921 FXUS61 KPBZ 050600 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 200 AM EDT Fri Jun 5 2026 .WHAT HAS CHANGED... Further southward adjustment to the Slight Risk area for severe storms were made for the latest foreast, with most of the area included. The area south of the I-68 corridor was included in a Marginal Risk for severe storms. && .KEY MESSAGES... 1) Continued dry and warm today 2) Showers and storms return Saturday a severe weather potential 3) Dry and warm again early next week && .DISCUSSION... KEY MESSAGE 1... Shortwave ridging will remain across the Upper Ohio Valley region today, with another dry day expected. Temperatures at 850mb are expected to be a degree or two Celsius warmer than yesterday, resulting in high temperatures in the mid to upper 80s for most areas outside of the higher terrain. With mixing, dew points should remain in the 50s today resulting in low humidity levels. KEY MESSAGE 2... A shortwave trough is expected to advance eastward from the Upper Midwest region Friday night, and approach the Upper Ohio Valley region Saturday. An initial vorticity max should bring increased cloud cover and a few showers by Saturday morning. Most guidance does indicate at least some breaks in the clouds, which should result in heating and building diurnal instability. Operational and ensemble guidance has trended toward more instability developing on Saturday after the initial vort max passage, with partial clearing/breaks in the clouds. The latest HREF and NBM Sfc CAPE is now progged from 1000-2000 j/kg north of I-70 by mid afternoon, with 0-6km shear from 30-40kt. At the same time, the shortwave trough axis is expected to be tracking across OH into western PA. Should these parameters verify, there will be a severe weather potential during the afternoon and evening hours. CAMS differ on exact timing and placement of storms, but agree on the overall idea of increasing thunderstorms and severe weather potential. At this time, the main window for severe storms appears to be from around 3pm-10pm. Damaging wind and large hail are both possible. A veering wind profile below 10kft could also result in rotating updrafts and a low tornado potential in discrete cells as well. Waning instability should result in a diminishing severe potential by late evening. The shortwave should exit the region overnight Saturday, through a lingering surface boundary is expected to set up across SE OH into Nrn WV, where continued chance POPs for showers/storms are expected through Sunday. KEY MESSAGE 3... A ridge building across the Upper Ohio Valley region should return dry and warm weather to the area on Monday. Ensembles indicate the ridge should slowly break down on Tuesday as a trough approaches from the Midwest. Shower and thunderstorm chances are expected to gradually increase from W-E Tuesday through Midweek as the trough slowly advances across the region. Above average temperatures are expected through mid week, though would be affect by any convection/cloud cover with the crossing trough. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... VFR is expected to continue through the TAF period, as high pressure begins to break down tonight. High cirrus cloud cigs are expected today, with the cu rule and model soundings indicate a scattered diurnal cu layer should develop. SW wind is expected to gust up to 20kt this afternoon with mixing. Increasing mid clouds are expected tonight ahead of an approaching shortwave trough. Outlook... Diminishing showers and lowering cigs are expected by Saturday morning with an initial disturbance ahead of the main trough. The trough is then expected to cross the region Saturday afternoon and evening, with scattered to numerous showers and thunderstorms developing. Exact timing of impacts to airports is uncertain, though general afternoon/evening impacts are likely. Cig restrictions are possible Sunday morning with low level moisture in place, before VFR returns late in the day under building high pressure. Restriction and shower/thunderstorm potential is expected to slowly return Tuesday from W-E with an approaching trough. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...WM AVIATION...WM