Area Forecast Discussion
Issued by NWS State College, PA

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307 FXUS61 KCTP 142347 AFDCTP Area Forecast Discussion National Weather Service State College PA 747 PM EDT Mon Aug 14 2017 .SYNOPSIS... A series of weak disturbances aloft will pass through the region over the next day or so. Fair and less humid weather will return for midweek before a new frontal system approaches the area Thursday and Friday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A weak area of low pressure, located over Virginia early this evening, will track south of the region overnight. At 23Z, most of the showers are confined to the Mason Dixon Line. However, expect showers to spread northward across the Susq Valley later this evening, as increasing isentropic lift develops ahead of a strengthening southerly low level jet. A blend of latest near term model output and radar trends support the highest (categorical) POPs this evening across the Lower Susq Valley, then a diminishing chance of showers after midnight, as low level jet shifts east. Across the northwest mountains, some modest CAPE combined with approach of shortwave over the Grt Lks could support a couple showers along the Warren/Mckean county border this evening. Mostly cloudy skies and a southerly breeze should hold temps up tonight, with mins mostly in the 60s. The exception will be across the northwest mountains, where evening cu will gradually diminish to mostly clear skies. The resulting radiational cooling should promote areas of valley fog over the northwest mountains late tonight, as depicted by the SREF and NAMDNG. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... Another weak wave of low pressure will be tracking south of Pa Tuesday morning, supporting a chance of showers over that part of the state. Expect a diminishing chance of showers across the southeast counties by afternoon, as wave passes east. Across the rest of the forecast area, diurnal heating combined with approach of shortwave should yield scattered afternoon showers/tstorms. Current model output suggests upper level shortwave and best large scale forcing will be exiting the area by early afternoon, so dont`t expect coverage of showers/storms to be that great. Latest NationalBlend/Superblend indicate afternoon POPS in the 20-30 pct range. Model soundings showing fairly impressive deep layer shear, but relatively dry air and only modest CAPEs indicate a low chance of severe weather. Partly sunny skies should boost temps to the low and mid 80s in most locations by Tuesday afternoon. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... Wednesday continues to look dry for now. However, the remnants of a weak cold front from the north drops southward toward the area. 00Z EC showed a low with strong warm advection for Thursday. The EC was deeper than faster with the low on Thu. Some variation with guidance with the end of the week. For now, did edge the POPS up some for Sunday and Sunday Night, to line up with others, the blend, and timing of the front better. Did not want to go too high, as events lately are largely clusters of convection. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Expect CIGS to lower overnight, along with some fog. Some showers to linger across the far south overnight into at least Wednesday morning. Central areas should see improvement by late morning or early aft. A cold front dropping southeast could result in a shower or storm across the northwest by late aft. .OUTLOOK... Wed...VFR. No sig wx. Thu-Fri...VFR. Sct Tstm impacts likely. Sat...No sig wx. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...Fitzgerald SHORT TERM...Fitzgerald/La Corte LONG TERM...Lambert/Gartner AVIATION...Martin

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