Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 241910 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 310 PM EDT Mon Jul 24 2017 .SYNOPSIS... A stagnant mid-level trough will keep very-humid conditions over the region today with a continued threat for showers and thunderstorms. Dry conditions are expected Tuesday through early Thursday. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
A moist, but weakly-unstable airmass remains this afternoon in the sern quadrant of the forecast area ahead of an advancing cold front. Showers and storms have developed in this unstable airmass. But morning cloud cover has limited the magnitude of instability, with updrafts unable to overcome the moderate shear. Storms should exit late this afternoon save for lingering showers in the ridges and possibly coming off the lake. Dry air and steep low-level lapse rates are leading to stratocu advancing from the lakes across the region through the evening. These clouds should clear by morning amid broad subsidence.
-- End Changed Discussion --
&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --
Upper-level heights will rise on Tue ahead of a shortwave ridge, and broad surface high pressure will build into the Great Lakes region. The drying boundary layer and overall subsidence will support a dry, seasonable forecast for Tue/Wed. Low-level moisture will begin to increase again Wed, which will help maintain above-average minima despite light wind and increasing cloud cover.
-- End Changed Discussion --
&& .LONG TERM /THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
Models are consistent for Thu in digging a deep upper-level trough along the Appalachians, which will act on an increasingly-moist and unstable airmass as a cold front crosses the region. Showers and storms along the boundary are highly probable, and PoPs were increased to reflect this expectation. The forecast for Friday into the weekend gets a bit muddy, as the evolution of the upper trough varies among the medium-range models. If the trough progresses sewd, then the weekend is shaping up to be dry and sunny, with seasonable highs. But other model solutions open the upper wave across the Appalachians, keeping the threat for clouds and precipitation (especially overaforementionedthe eastern ridges) into Friday and Saturday. With an amplified upper ridge persisting in the wrn CONUS, it is likely that a mean trough will remain over the ern CONUS for the better part of the extended forecast. The net effect will be overall a seasonably-warm and -active weather pattern.
-- End Changed Discussion --
&& .AVIATION /19Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
At 19Z, a broken line of showers and thunderstorms was located from KDUJ-KAFJ-KPKB, with greatest coverage near MGW. MVFR ceilings will linger across the area today. The slow-moving boundary will sag south through the remainder of the afternoon. By evening, VFR conditions should persist over the area. Lingering low-level moisture may produce some restrictions in the early morning hours Tuesday. Otherwise, VFR conditions are expected through Wednesday. .OUTLOOK... VFR is expected to prevail through mid-week as high pressure builds in. Moisture will return Thu ahead of a sewd-moving trough.
-- End Changed Discussion --
&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$ Kramar

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.