Area Forecast Discussion
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000 FXUS61 KPBZ 261915 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 315 PM EDT Wed Jul 26 2017 .SYNOPSIS... Showers and thunderstorms return Thursday and Friday as a cold front and upper level low pressure system move through. Dry and seasonable weather returns this weekend. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Dry weather is expected tonight, although clouds will increase in advance of the cold front moving into the region. The cloud cover will keep temperatures about 5 degrees warmer than last night`s values. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... Similar to previous forecast, forecast confidence for this period remains low. The one general concept that the deterministic models agree on is that the overall rain shield on Thursday should be somewhat farther to the south. Have increased the gradient in pops from north to south, pushing the line of likely pops farther south and keeping chance pops to the north. However, overall precipitation along the cold front remains somewhat unorganized. Due to concerns about instability, the risk of convective weather on Thursday has been lowered by the Storm Prediction Center down to a marginal area across all counties. Damaging winds remain the primary threat. There should be a bit of a lull in precipitation Thursday night as the surface front plunges south, but precipitation will redevelop as an upper level low drops into the Ohio Valley on Friday and helps to restrength low pressure along the front. All locations have likely pops on Friday. Forecast models continue to slow down the departure of precipitation Friday night into Saturday, and have decided to keep pops in the forecast longer through this time period, with morning showers on Saturday only expected in Pittsburgh and locations east. While the severe threat has diminished on Thursday and is not present on Friday, flooding could still be a possible concern. The entire vertical sounding remains quite moist, and warm cloud depths could support plenty of downpours. In addition, flow will be rather weak on Friday, meaning that any storms that do develop will be slow moving in nature. Rainfall could range anywhere from a half inch along Interstate 80 to more than 2 inches in southernmost Tucker County from Thursday morning through Saturday. However, no flood watches have been issued at this time because of the extended time period over which the rain is expected to fall. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... High pressure across the Great Lakes should keep weather dry through the extended forecast, with temperatures remaining seasonable through the period. A front may approach from the northwest by the middle of next week, but the timing remains highly uncertain. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... VFR conditions today with light and variable winds. A couple of hours either side of sunrise, possibility of restrictions of 3-5 miles in BR/HZ. By later in the day Thursday, expect chance of scattered showers and thunderstorms. .OUTLOOK... Restriction chances return Thursday night through Friday and possibly into Saturday as low pressure impacts the Ohio Valley. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$ is the U.S. government's official web portal to all federal, state and local government web resources and services.