Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
051 FXUS61 KPBZ 190614 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 214 AM EDT Sat Sep 19 2026 .WHAT HAS CHANGED... There has come to a be a bit more agreement in the potential of heavy rainfall this weekend and into next week. && .KEY MESSAGES... 1) Rain chances return Sunday into early next week. Rain may be heavy at times, and could lead to localized flooding and/or river rises. && .DISCUSSION... KEY MESSAGE 1... Another period of extended wet weather is forecast to enter the area Saturday night and into Sunday morning. Ascent will mostly be due to a shortwave trough and ridge breakdown in a transition to more quasi-zonal flow for the beginning of next week. The first round will arrive Saturday night into Sunday with the bulk of the moisture axis focused over the northern forecast area to begin the wet period. The totals up north point to the HREF giving a 60% to 70% probability of exceeding 0.50". However, the 90th percentile here shows some 1.00" to 1.75" 24 hour rainfall amounts. With PWAT amounts in the 1.8 to 2.0 range, a 90th percentile amount is certainly more probable. The heaviest rainfall is expected arrive by Sunday morning in the 12Z to 16Z timeframe. This 24 to 36 hours period will likely consist of a few waves of convection bringing heavy rainfall to the region. The other issue will be the MU CAPE values for Sunday tops off at around 1000 J/Kg and this may be enough to increase the efficiency in the rainfall rates. While there likely won`t be enough instability for severe concerns, there is quite a bit of low level shear in place. Will need to watch for an isolated spin- up. Continued rain chances are forecast into Monday, Tuesday, and Wednesday, though temperatures will be cooler and rain is expected to be mostly stratiform. That being said, long duration accumulations have the potential to be sizable, with 90th percentile 48hr totals of up to 2" to 4". While this wouldn`t pose as much a threat for flash flooding, areal flooding and river flooding chances may increase should this high-end potential be realized. The primary way to realize high end potential would be to be positioned immediately north of the stationary boundary with overrunning and/or on the northwest side of a developing coastal low. Should the stationary boundary be too far south or the coastal low to far east, these threats would not be realized. These scenarios will need to be monitored through the weekend and into next week. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... Expect mainly VFR conditions tonight with the exception of MGW and HLG where some fog development is possible. Otherwise, expected light and variable winds through the rest of the night and into the coming day. The next system to impact the area will arrive late tonight. have put some PROB30s at FKL, DUJ, ZZV, and PIT to cover the potential arrival of precip towards the end of the TAF period. Some MVFR impacts are possible with this arrival. Outlook... Restrictions are likely to return Saturday night into Sunday morning with an increased chance for showers and thunderstorms associated with an approaching disturbance. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Milcarek/Shallenberger AVIATION...Shallenberger