685 FXUS61 KCTP 270240 AFDCTP Area Forecast Discussion National Weather Service State College PA 1040 PM EDT Thu May 26 2022 .SYNOPSIS... An upper low to the west will slide closer on Friday, pushing a cold front through the area. Showers and thunderstorms are expected, some with heavy rain and damaging wind gusts, on Friday. The upper low will be overhead on Saturday, generating more showers. Sunday and Memorial Day look dry and increasingly warm. && .NEAR TERM /UNTIL 8 AM FRIDAY MORNING/... Showers crossing through the Alleghenies are still devoid of thunder. With little thunder upstream (SWrn VA) and stable low layer in place, have removed mentions of TS from the wx grids in the near term. While an isolated elevated strike may occur overnight, it's not significant enough of a chance to carry, esp over a large area. Temps won't move much overnight as the clouds persist and lower some, esp in the east. LNS has gone down to IFR, and others should follow. Upslope and lowering clouds should develop patchy DZ for the east through the rest of the night. && .SHORT TERM /8 AM FRIDAY MORNING THROUGH SATURDAY/... The highest probability of rain will be Friday, as low level jet pushes across the region. NBM POPs between 90-100pct continue to look in good shape based on the strong upper level diffluence and 40-45 kt SSW LLJ ahead of closed low and pwats 2SD above climo. Current model guidance suggests early cloud cover will limit heating significantly over the western half of the state. However, there could be enough breaks and resulting instability over the central/eastern third of the forecast area to support severe convection in the afternoon. This convection could have a difficult time maintaining its intensity as it encounters a potential stratus layer and cooler/more stable airmass east of the Susq mainstem. Shear profiles appear favorable for storm organization and the combination of 0-1km shear and low LCLs suggest an isolated tornado is even a possibility over the southeast counties near the aforementioned western edge of the stratus deck - if enough heating is achieved across the Central Mtns during the late morning/early PM hours. The latest SPC outlook has a SLGT risk of severe across the SE third of PA, with locally damaging wind gusts the primary threat. The combination of instability, high pwats and fairly unidirectional swrly deep-layer shear of 40-50 kts could lead to training cells, torrential downpours and excessive rainfall in a few spots of eastern Pa Friday afternoon/evening. The wettest members of the 00Z HREF support the possibility of spot amounts near 2 inches over the southeast part of the forecast area. Based on latest FFG, this could potentially result in minor flooding for a few locations. The low level jet and plume of deepest moisture is progged to shift east of the region Friday evening. However, lingering showers appear likely into at least early Saturday in association with passage of upper low. Diurnal heating ahead of the low could spawn a few afternoon thunderstorms across the eastern half of the state. However, meager cape and weak shear profiles indicate little threat of severe weather. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... The upper low will finally push east of PA Saturday night and drier air will begin to work its way in from the west, leading to a period of dry weather through midweek. Sunday looks like a very pleasant day with surface ridging passing overhead and temperatures topping out in the mid 70s to low 80s. Summerlike temperatures return just in time for Memorial Day as an upper-level ridge of high pressure establishes itself over the eastern United States. Will see a few more clouds across the northern tier vs. closer to the Mason-Dixon line as rounds of energy ride atop the ridge from the Great Lakes into Ontario/Quebec. Temperatures Monday through Wednesday look to warm into the mid 80s to low 90s as the upper ridge axis centers itself near the Commonwealth. Increasing Gulf moisture through the week will likely make for heat indices in the low 90s for locales across south central PA, prior to an approaching shortwave trough and cool front bringing the return of showers and storms into Thursday. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... A few showers will brush the far western part of the area this evening, in the area where temperatures are warmer. The main thing overnight will be that CIGS will continue to lower, given the moist southeast flow. Some patchy drizzle will be possible, especially across the east. Low CIGS will persist for much of Friday, especially across eastern areas. For now, went with showers on Friday. Potential for storms with storng winds; but a bit early to pinpoint, given that clouds will take some time to burn off. Improving conditions for the holiday weekend, as the cold front moves east of the area on Saturday. Outlook... Sat...Improving conditions. Sun-Tue...Dry weather with VFR conditions. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert/Dangelo NEAR TERM...Lambert/Dangelo SHORT TERM...Lambert/Fitzgerald LONG TERM...Guseman/Wagner AVIATION...Martin