Area Forecast Discussion
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000 FXUS61 KPBZ 191653 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1253 PM EDT Tue Sep 19 2017 .SYNOPSIS... Generally warm and humid conditions will prevail for the next week across the area. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Main change was to increase and expand PoPs eastward a bit to UCP and the northern WV panhandle. 12Z soundings show a cap above 700mb at KPIT but no such feature at KILN. Model soundings suggest that the cap at the office will hold on, just barely, suggesting a decent eastern edge to precipitation chances. While the bulk of the activity to our west will fall apart as it bumps into the ridge over the CWA, the HRRR looks reasonable in suggesting isolated/scattered convective development in the western counties during the afternoon hours. Equilibrium levels above 30k feet suggest thunder possibilities and have added it in. Temperatures are in good shape and made few changes there. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... While the front continues to struggle to advance eastward through tonight and into Wednesday, the attendant mid-level circulation and weakening cold pool will give it a whirl on Wednesday. GFS/EC guidance suggest it should start to slink SE as is weakens rapidly from afternoon into evening, and the bulk of the mid-level cooling is likely to remain to the SW of the area as it transits SE and falls apart. With that in mind, a chance/slight chance mention of rain showers will remain in the forecast for Wednesday afternoon/evening, especially over eastern Ohio and northern West Virginia. With the passage of the wave Wednesday, high pressure will again resume control with steady warming into the latter half of the week. Fries && .LONG TERM /FRIDAY THROUGH MONDAY/... Deepening troughing over the western CONUS and amplified ridging over the eastern CONUS will yield strong warm advection into the Ohio Valley through the weekend and beyond. This will be especially true as surface high pressure slowly trudges from directly overhead to ever-so-slightly east of the area by early next week. This will increase mixing potential, decrease any easterly moisture fetch into the area over the ridges, and yield a surge in 850 mb temperatures toward +17 to +19C for several days. As a result, highs in the lower elevations will jump at least toward the mid 80s, if not higher, and even in the higher terrain, upper 70s will be possible. With high pressure in control, and ridging amplifying overhead, no rainfall is anticipated during the long term or beyond. Fries && .AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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VFR conditions with diurnal CU and increasing mid/high clouds are expected into the overnight hours as a weak upper trough approaches. Clouds should limit fog potential again tonight/Wed morning., but will go with some restrictions at AGC/FKL/DUJ where less cloud cover could allow for some fog development. .Outlook... Other than local morning fog, no widespread restrictions expected through Sun with building ridging.
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&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$

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