Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
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253 FXUS61 KCTP 060245 AFDCTP Area Forecast Discussion National Weather Service State College PA 1045 PM EDT Fri Jul 5 2024 .SYNOPSIS... * Persistent heat and humidity stick around through next week * Aside from a few isolated showers and storms on Saturday, a dry weekend is expected * Trending wetter toward the middle of next week with daily chances for showers and thunderstorms. && .NEAR TERM /UNTIL 8 AM SATURDAY MORNING/... Still remarkably muggy out there this evening with temperatures holding in the middle 80s and dewpoints in the middle 70s across southeast PA. The persistence of heat/humidity with no real relief overnight has prompted the extension of the Heat Advisory until 8PM Saturday for the Lower Susquehanna Valley. Mid level ridge axis overhead combined with a strong cap (9.5-10.5C at 700 mb) and earlier widespread and relatively thick, layered cloud cover has minimized development of much shower/storm activity thus far. Conditions have become more favorable for shower activity this evening across the west and will spread east overnight across the Central Zones and much of the Susq Valley as a subtle shortwave/few deg C of cooling aloft moves NE up the Ohio Valley. Showers could still linger until daybreak in the far NE. A few rumbles of thunder are possible, but recent trends indicate the threat for severe weather is very low overnight. Sfc dewpoints in the upper 60s to mid 70s and the increasing cloud cover advecting in with the decaying storms from the SW will lead to a very warm and muggy night with min temps similarly in the upper 60s to mid 70s. Localized, briefly cooler temps in the mid 60s may occur where rain falls. Saturday morning will epitomize the phrase "air you can wear". && .SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... Focus for t-storms will shift to the eastern third of the Commonwealth (Mainly Saturday PM) along and ahead of a weak cold front. A second area of SHRA/Low-topped TSRA are possible along the boundary of the Lake Erie Breeze that should reach NW Warren County and perhaps NW McKean Cty. HREF and its members suggests limited storm coverage likely owing to neutral height falls and weak llvl convergence. Cold front passage has trended a bit faster, so majority of storms should remain east of the area tomorrow and keep most locations dry. Ahead of the front, surface temperatures in the middle 90s will combine with dewpoints still in the upper 60s to middle 70s to produce heat index values near or above 100F Saturday afternoon where a Heat Advisory remains in effect. With little to no chance of rain/storms, only limiting factor for heat index will be the frontal passage. Behind the cold front, dewpoints will trend a bit lower (lower 60s) and cap heat index in the 80s (north & west) and 90s (outside the Lower Susquehanna Valley). High pressure builds in Saturday night and provides a slightly less humid and dry (rain-free) end to the first weekend of July. Lows by Sunday morning will dip into the upper 50s in northwest but stay in the low 70s in the southeast. Clearing skies and ideal radiational cooling should support valley fog in the northwest on Sunday morning. Plenty of sunshine expected Sunday with clear skies Sunday night and temperatures similar to Saturday/Saturday night with slightly lower humidity. It may be worthwhile to find a pool or body of water near which to participate in outdoor activities this weekend. && .LONG TERM /MONDAY THROUGH FRIDAY/... Diurnally driven showers and thunderstorms appear possible on Monday with easterly/southeasterly flow bringing an increase of moisture to central Pennsylvania. Surging PWATs into Tuesday will promote higher chances of precipitation later in the evening and into Wednesday morning as a surface cold front approaches the region. Precipitation is expected to continue through late Wednesday when the cold front shifts east of the area, but have retained PoPs through the end of the Wednesday timeframe based on some remaining uncertainty with regards to timing. Some divergence in model solutions on Thursday and into the end of the week with the North American suite of models outlining surface high pressure taking hold across the region while the European suite of models outline a continuation of showers and storms throughout the period, so have capped chances to SChc outside of peak daytime heating hours where slightly higher probabilities emerge. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Scattered showers, and possibly some thunder, will approach from the Ohio Valley later this evening and should push northeastward across the area through the overnight. Ensemble guidance suggests that we will see a period of MVFR cigs later tonight into Saturday morning over the western (BFD, JST) highlands and the central mountains (AOO, UNV, and possibly IPT). The western highlands may see cigs dip to IFR for a few hours centered around daybreak (~60% chc). Improvement is expected areawide on Saturday, with all airfields returning to VFR conds by afternoon. Outlook... Sun...AM fog possible; otherwise, no sig wx expected with slightly lower humidity. Mon...Predominantly VFR w/ no sig wx expected. Tue-Wed...Scattered showers/storms and restrictions possible. && .CTP WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM EDT Saturday for PAZ036-056-057-059- 063>066. && $$ SYNOPSIS...Banghoff NEAR TERM...Lambert/Banghoff SHORT TERM...Lambert/Banghoff LONG TERM...NPB AVIATION...Evanego