Area Forecast Discussion
Issued by NWS State College, PA

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603 FXUS61 KCTP 231132 AFDCTP Area Forecast Discussion National Weather Service State College PA 732 AM EDT Thu May 23 2024 .SYNOPSIS... A cold front over Northwestern PA will push southeast through the region by early this afternoon preceded by an area of showers and thunderstorms. A ridge of high pressure will slide east across the state Friday brining a nice day with dry conditions and comfortably low humidity. More clouds and an uptick in humidity will arrive for the upcoming weekend and persist through Memorial day with a period or two of showers and possible thunderstorms, mainly on Saturday and Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A period of enhanced meso-B lift will accompany the nose/left exit region of a rather potent, 90 kt upper level jet headed our way from the middle ohio valley. An expanding cluster of fast, NEWD moving showers and thunderstorms were impacting the Western (and soon the Central Mtns and Susq West Branch Valley) over the next 1-3 hours. Stronger convective cells are capable of localized strong wind gusts as their water and small hail-loaded cores collapse through the 35 to 40 kts 850-700 mb speed max. The cold front will drift south to near the Mason/Dixon line by the mid afternoon hours and stretch out more in an east/west direction. This will limit any chance for showers or a thunderstorm to primarily the southern tier counties of PA after 18Z today. SFC dewpoints behind the cold front will fall quickly through the 50s and into the 40s several hours behind the front later this morning and this afternoon with sunshine being filtered by high clouds. The high level cloudiness extending into Northern PA should hold temps down with expected highs ranging from the mid 70s to low 80s, which are still slightly above climo for this time of year. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... Rain chances trend lower from north to south tonight into Friday as surface and upper level ridging builds over the area. Max POPs 25-35% are over the southern tier of central PA near a stalled/pivoting quasistationary front and axis of highest PWATs. Friday looks like a pleasant day across most of the region with temperatures in the upper 70s to mid 80s and a good amount of sunshine. The front lifts back to the north as a warm front Friday night with showers likely by Saturday morning over the western Alleghenies. More widespread showers and storms will develop Saturday afternoon with daytime heating and some enhancement with a prefrontal trough. Saturday will not be a washout by any means, but those with outdoor plans should monitor the weather and head inside if you hear thunder. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Compared to Saturday, the chance for showers and thunderstorms on Sunday will be lower, owing to a weak surface high building across the Lower Grt Lks into PA. However, with a warm front approaching, we do carry slight chance to chance PoPs Sun afternoon, with PoPs increasing to likely Sunday night as the warm front crosses through the region. A deepening upper trough will then likely result in a period of unsettled weather continuing into Memorial Day and the first half of the upcoming week with mainly scattered, diurnally- driven convection expected. && .AVIATION /12Z THURSDAY THROUGH MONDAY/...
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Thunderstorms across the eastern airspace will continue moving eastward early this morning with MVFR vsbys/cigs with locally lower reductions. Rain is expected to continue for the next couple of hours with MVFR cigs/vsbys expected. Improvement is expected by late morning with the majority of the area trending towards VFR conds by 16-18Z Thursday. Some clear skies remain possible across N PA later this afternoon. Guidance has started to indicate some chance of low vsbys and cigs overnight Thursday into Friday morning, with recent GLAMP guidance and RAP guidance suggesting JST to experience an extended period of IFR/LIFR conditions. Given some uncertainty with regards to extent, have kept restrictions limited to JST at this time after 08Z Friday. Outlook... Fri-Mon...Mainly VFR, but chance of showers/AM patchy fog.
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&& .CLIMATE... Daily record maximum temperatures for 5/22: Harrisburg96/1941 Williamsport95/1941 Altoona88/2013 Bradford84/2013 State College89/1975 && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Lambert LONG TERM...Lambert/Fitzgerald AVIATION...NPB CLIMATE...Steinbugl