FXUS61 KCTP 200143 AFDCTP Area Forecast Discussion National Weather Service State College PA 943 PM EDT Tue May 19 2026 .WHAT HAS CHANGED... * Little threat for wind gusts over 40 KTS early tonight across NW PA with the line of SHRA/TSRA well in advance of a cold front. * Increasing odds for a noticeably cooler and rather wet start to Memorial Day weekend (lowered max temps for Sat by several deg F with extensive low clouds, llvl easterly flow and periods of rain/drizzle/ridge shrouding fog. && .KEY MESSAGES... 1) Scattered strong thunderstorms are possible across the NW mtns early tonight, then across south central PA and the Lower Susq Valley Wednesday afternoon 2) Major cooldown arrives Thursday and lasts into Memorial Day weekend with widespread soaking rainfall (over 1 inch) likely Friday and Saturday && .DISCUSSION... KEY MESSAGE 1: Scattered strong thunderstorms are possible across the NW mtns early tonight, then across south central PA and the Lower Susq Valley Wednesday afternoon SPC trimmed back its SLGT Risk area for SVR out of NW PA with its 0045Z update. A weakening line of showers and thunderstorms will be moving across our NW Mtn zones between 02-05Z with some wind gusts of 35-40 KTS possible, more so across the region south of Route 6 where the best combination of SFC based CAPE over 1000 J/KG and DCAPE of ~1000 J/KG will exist. Elsewhere across Central PA and the Susq Valley, expect a partly to mostly cloudy and rather muggy night with sfc Tds in the low to mid 60s in most places. More comfortable conditions will occur across the NW Mtns where rain-cooled air and sfc dewpoints only around 60F will be found. Dual to multi-Layered clouds with just some widely scattered light showers Wednesday morning will be followed by a few periods of showers in the early-mid afternoon, near and to the north of I-80. Convective focus shifts to south central PA Wednesday afternoon with narrow plume of weak to moderate CAPE fcst ahead of the aforementioned cold front. Steep low level lapse rates may support a few instances of strong to severe winds. The magnitude & location of the severe threat will be highly dependent on CFROPA timing and amount of cloud cover. SPC MRGL risk (level 1/5) covers the southeast half of the CWA where max temps are fcst btwn 80-90F. ----------------------------------------------------------------- KEY MESSAGE 2: Major cooldown arrives Thursday and lasts into Memorial Day weekend with widespread soaking rainfall likely Friday and Saturday Relief from the early season heat wave arrives in earnest on Thursday with max temps 20-30 degrees lower vs. Wednesday across the southeast half of the forecast area. Strong high pressure slides from the Lower Great Lakes to off the New England coast to close out the week. Model data shows the high channeling southward down the east-side of the Appalachians, setting up a cold air damming type event heading into Memorial Day weekend. Earlier shifts noted, "We may not be bearish enough on daytime temperatures." Did trim max temps Saturday down by 4-5 deg F given the thick clouds, moderately strong east-serly llvl flow and periods of soaking rain that will dampen at least the start of the holiday weekend. WPC 48hr QPF amounts are quite wet with a widespread 1-2.5 inches fcst from 12Z Friday to 12Z Sunday. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... Widespread VFR conditions prevail as of 01Z Wednesday, with these conditions likely (80-90% confidence) to continue at all airfields outside of BFD through ~12Z Wednesday. In this timeframe, approaching a line of SHRA with embedded TSRA will approach NW PA closer to the ~03/04Z timeframe. This will likely bring low-end VFR to high-end MVFR ceilings which will persist throughout the entire overnight period and throughout much of the evening hours on Wednesday (~22/23Z Wednesday). Closer to the 12Z timeframe, increasing signals for IFR at BFD based on a consensus of HREF ensemble members and multiple cycles of GLAMP model guidance, so have decided to include these in the TAFs with moderate (~40-50%) confidence on timing. A brief period of lower ceilings trending towards LIFR will be possible; however, confidence remains too low for inclusion in the 00Z TAFs. Elsewhere, the aforementioned line of SHRA/TSRA is expected to diminish in intensity/coverage overnight, leading many airfields unlikely to receive any SHRA in the 00Z-12Z Wednesday timeframe. Recent HREF runs have been fairly consistent with the progression of a low-level cloud deck across all of central Pennsylvania, so have included these mentions and slightly adjusted timing based on recent HREF/NBM/GLAMP model guidance in order to outline initial onset of MVFR restrictions. There is high (~70-80%) confidence on SHRA/TSRA reforming during the late morning to early afternoon hours (mainly after 16Z) with increasing coverage into the evening hours. Current SHRA mentions have been included at all terminals across central Pennsylvania based on recent forecast/HREF/GLAMP model guidance with most uncertainty with respect to timing. In terms of TSRA coverage, the highest potential at this time is outlined across SE PA (MDT/LNS) where enough instability will be present in order for some mentions in the TAF. At this time, have trended towards PROB30s; however, if the cold frontal passage trends quicker than forecast, could see mentions removed at MDT/LNS in future TAF packages. Outlook... Thu...Lingering showers across S PA, restrictions possible. Fri...Restrictions likely with rain moving in from south to north, lasting into Fri night. Sat-Sun...Restrictions likely with rain. && .CLIMATE... The following climate sites across central Pennsylvania set new daily high temperature records for May 18th: * A record high temperature of 92 degrees was set in Altoona, breaking the previous record of 91 degrees initially set back in 1962. This record was tied two times previously, back in 1996 and 2017. * A record high temperature of 86 degrees was set in Bradford, breaking the previous record of 85 degrees set back in 1962. --------------------------------------------- As of the 5PM Daily Climate Reports on May 19th, two stations across central Pennsylvania have *potentially* broken their warmest low temperature records for May 19th: * Harrisburg has an observed low temperature of 68 degrees, which would break the previous record of 67 degrees set in 2017. * Bradford has an observed low temperature of 61 degrees, which would break the previous record of 60 degrees set in 1998. ** Please note the two above *potential* records are not finalized until the midnight climate reports are sent out, which should occur sometime around ~2AM 5/20. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ WHAT HAS CHANGED...Lambert/Steinbugl/Bauco KEY MESSAGES...Lambert/Steinbugl/Bauco DISCUSSION...Lambert/Steinbugl/Bauco AVIATION...Beaty CLIMATE...Beaty