Area Forecast Discussion
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000 FXUS61 KPBZ 250540 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 140 AM EDT MON JUL 25 2016 .SYNOPSIS... A weak and slow moving cold front will pass through the area later today, bringing the risk for more showers and storms. Area dries out by mid week. Above normal temperatures will remain for most of the week. && .NEAR TERM /THROUGH TODAY/... For the overnight, not much change needed. Minor adjustments to pops late and cloud cover. Temperatures have been updated with a blend of hires guidance. A weak cold front will try and cross the region late today, before losing most of its structure as the evening approaches. Expect activity to re-fire today, but timing and coverage remain an issue. Much will depend on what happens with the MCS over the upper midwest and how its large scale outflow will be maintained and what convection may fire with the crossing of the wind shift. Additionally, debris clouds from the aforementioned complex will play a role by restraining max heating potential and in turn overall instability. Plenty of moisture already in place with most locations reporting surface dewpoints near or just above 70 degrees. This would mean today`s convection will be very efficient rain makers, allowing for a high risk for heavy downpours. Models are showing different stories on when and where convection may erupt, as they are attempting to decipher the effects of the western complex and where its energy will eventually travel. Since questions remain on location and timing, have left pops in the chance category. Temps were constructed using the Bias-Corrected blend of hires guidance. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... Front will fizzle out tonight and do little to eject the humid airmass in place. Models are in pretty good agreement that any convection will die out tonight. Noticeably drier air does move in from the north in the mid and upper levels, however humidity levels look to remain rather high through Tuesday with the lack of low level dry advection. It will take until Tuesday night and then finally into Wednesday, when the juicy low level air is shoved to the south. Both Tuesday and Wednesday look dry with a good deal of sunshine. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... Highlights: - Continued above normal temperatures - Best shot at rain arrives Thursday night into Friday Overall no real change to synoptic pattern for much of the week as a broad H5 anticyclone dominates the southern 2/3rds of the CONUS. Our mid level height values will fall a few decameters, but not enough to usher in temps where they should be for this time of year. Based on H8 temps not see a stretch of 90F+ weather like this weekend. However, would not be surprised for eastern Ohio to be right around 90F for daytime highs most of the week. Baroclinic zone that crosses Monday night weakens and washes out over the central Appalachians Tuesday as flow become parallel to the boundary and it encounters increased subsidence. In its wake, slightly cooler weather than what we have experienced takes hold for mid week. By weeks end, another shortwave trough traverses the region sweeping a cold front through. Timing differences reside with ECMWF and GEFS, but ECMWF keeps the recent summer trend going of shortwaves passing outside peak heating hours. GFS opts for a Friday afternoon passage. Either way, the next shot of widespread precipitation appears to be Thursday night into Friday. Zonal flow re-establishes for the weekend with temperatures near the climo average of lower to mid 80s. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... Fairly widespread MVFR conditions will be likely overnight periodically as low level moisture pools and transient fog forms. CIGS will likely periodically run IFR at KFKL and KDUJ as well. A system moving in from the NW for Monday will increase the chances of showers and thunderstorms as is slowly drifts through the area, which also may locally restrict conditions on Monday. After this system drifts through, low level moisture will remain in its wake, which could again mean the return of low clouds and fog for Monday night. Fries .OUTLOOK /MONDAY NIGHT THROUGH FRIDAY/... After the passage of the cold front Monday night, no widespread IFR conditions are expected at this time. && .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.