584 FXUS61 KPBZ 090723 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 323 AM EDT Mon Jun 9 2025 .SYNOPSIS... Unsettled weather will be the main concern for today as a cold front will cross the area today and bring the potential for severe weather and flooding today and tonight. Expect high pressure and quiet weather by midweek. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... KEY MESSAGES: - Some patchy fog is present through dawn. - Slight Severe and Excessive Rainfall Outlooks for Today. --------------------------------------------------------------- The current conditions across the forecast area this morning feature some mainly clear skies but a few spots showing some fog development. There will be a few spots of patchy dense through dawn this morning. Some breaks in the cloud cover will be present after sunrise but mid and upper level cloud cover will begin moving into the region. Hence there may be a few concerns about instability heading into this event today. The 500MB closed low will swing the trough axis through IL/IN region by 16Z to 18Z. Timing pins the development of the line of storms into eastern OH by 18Z. At onset, the NBM and the HREF for that matter is only giving roughly 40% to 60% probability for 1000 J/Kg SB CAPE through the coming day. The agreement between the 2 ensembles paints the picture for a developed line of storms crossing the area. Model soundings across the area suggest an almost unidirectional profile from the southwest. This in place along with at least 40 knots of shear, will make for a damaging wind and isolated tornado threat with a 2% tor in place for the forecast area. The other concern here will be the threat of heavy rainfall that could lead to some flooding. The storm motion for development later today will be roughly 20 knots and should be fast enough to nix any flooding potential. As well, the 1.2 to 1.3 PWATs only fall within the 75th percentile. The one concern here is with training storms and if storms fall into this motion, expect the instance of flooding. Given the nature of todays event, chose to hold off on the Flood Watch as instances will be isolated. Additional rainfall will be possible into tonight. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... KEY MESSAGES: - Unsettled weather continues through Tuesday morning. - Conditions dry during the daytime on Tuesday. ---------------------------------------------------------------- By tonight, the upper trough finally advances eastward across the Ohio Valley and northeast of the area by Tuesday evening. More showers and storms will accompany this passage and, given amount of rain that will have fallen on prior days, carry a continued threat for excessive rainfall and localized flooding. With the front out of our region, Tuesday night is expected to be dry. Some fog development is expected towards dawn. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... KEY MESSAGES: - Dry and less humid weather returns Wednesday through Thursday night. - Chance for rain returns Friday through Sunday. ------------------------------------------------------------------- High pressure builds into the region Tuesday night into Wednesday resulting in dry weather from Wednesday through Thursday night, along with a gradual warming trend. A passing trough will bring a chance of rainfall back to the area for Friday. Deep-layer flow during this period will be out of the west-southwest and thus it will remain to be seen if the potential leads to any severe or flood risk heading into the weekend. In fact, the deep layer moisture advection setting up heading in to the weekend will certainly elevate a flooding concern given the continued southwest to northeast orientation of the moisture advection. Saturday and Sunday will need monitored. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... Areas of MVFR to IFR fog and stratus are expected to continue through early this morning. Where clearing has occurred, the stratus and fog were redeveloping with low level moisture in place. Expect this trend to continue through sunrise. After sunrise, mixing should dissipate the fog and gradually lift the cloud cigs back to VFR by mid to late morning. A prefrontal surface trough is then progged to approach and cross the region this afternoon and evening. Expect a line of showers and thunderstorms to develop ahead of this trough, with building diurnal instability through the day (afternoon CAPE values peak around 1000-1500 j/kg.) Included a period of IFR in thunderstorms at each airport for the most likely times of occurrence. Showers will linger after the thunder ends later this evening, with MVFR/patchy IFR overnight with low level moisture in place. Outlook... Restrictions are expected to continue into Tuesday morning, until the passage of a cold front. Expect a gradual improvement to VFR after FROPA, with VFR continuing through Thursday under high pressure. Restriction and shower/thunderstorm potential returns as low pressure approaches on Friday. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Shallenberger NEAR TERM...Shallenberger SHORT TERM...Shallenberger LONG TERM...Shallenberger AVIATION...WM