Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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699 FXUS61 KPBZ 300516 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 116 AM EDT Thu Jul 30 2026 .WHAT HAS CHANGED... No notable changes have occurred within the key message ahead of this weekend. && .KEY MESSAGES... 1) Dry and seasonable weather favored this week before widespread rain returns this weekend. && .DISCUSSION... KEY MESSAGE 1... Rising pressure heights over surface high pressure will allow area temperature to return closer to normal today and ever so slightly above normal Friday while providing dry weather and abundant sunshine. This pattern changes as an upper trough drops southeast out of the northern Rockies towards the Ohio River Valley by Friday evening before crossing the region by early next week. The combination of jet dynamics providing lift with weak moisture advection ahead of its axis results in increased shower and thunderstorm chances. Little more can be said at this point due to large variances in the shape and eastward progression of this trough creating different precipitation timing (along with environmental threats). The range of outcomes seems to be bounded by 1) a more progressive trough hinted by the initial 00z NAM model run that results in storm coverage peaking by Saturday afternoon/evening; and 2) a slower and slightly deeper trough favored by a healthy portion of GEFS ensemble members that results in storms peaking Sunday morning/afternoon. Ensemble clusters generally fall in between these two ranges (peaking late Saturday into early Sunday) and where the current forecast aligns. Due to this variance, precipitation chances could vary in the coming days as models attempt to come in alignment. Additional uncertainty arises in the timing of trough exiting, ranging from Sunday afternoon/evening to Tuesday. So long-range PoP outlooks may also experience similar fluctuations in the coming days. Regardless of the scenarios, the overall hazard risk appears low as buoyancy is likely to be limited (outside of a narrow corridor near the Laurel Highlands on Sunday, probability of SBCAPE being less than 1000 J/kg is greater than 80%). The only hazard to monitor is flood risks as there could be enough of a Gulf moisture draw to push PWAT values near/above the 90th percentile; if this occurs while storm motion is slow and enough instability manifests to aid rainfall rates, localized flash flooding risks could materialize. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... High confidence VFR forecast through the TAF period with diurnal mixing resulting in a few cu and occasional NW wind gusts to 20kts. Outlook... VFR is likely through Saturday morning under the influence of high pressure. Slow upper trough passage will result in multiple periods featuring shower and thunderstorm chances this weekend into early next week. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Frazier AVIATION...Frazier