FXUS61 KCTP 200115 AFDCTP Area Forecast Discussion National Weather Service State College PA 915 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 /00Z WEDNESDAY THROUGH SUNDAY/... VFR conditions are expected to prevail for this hot afternoon. Winds have become gusty with daytime heating and ridging building from our south, gusts could reach up to 25kts. Convection is already being observed over the southwestern airfields, but forcing is weak making coverage and strength of these storms uncertain for the remainder of today. Instability is high enough that any storm that does develop will likely contain lightning until after sundown. The most likely airfields to be impact by these storms through 00Z will be JST and AOO. Tonight, the low pressure system over the Great Lakes will approach from the northwest. This will cause ceilings to lower and bring additional rain chances from northwest to southeast for the day on Wednesday. MVFR ceilings are likely ahead of the cold front at BFD, JST, AOO, UNV, and IPT. The only site likely to experience IFR ceilings will be BFD early tomorrow morning, elsewhere should remain MVFR or better. Lastly, LLWS mentions were included at our northern terminals (KBFD/KIPT) through the evening/overnight hours as 900 mb winds increase to around 40 kts due to pressure gradient between low pressure over Southern Canada & Bermuda High over the Western Atlantic. Outlook... Wed...Restrictions probable through Wednesday night with widespread showers/storms along CFROPA. 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. ** Note: The high temperature for State College will be reported around 7AM on 5/19. This is due to the State College CO-OP observations running 7AM-7AM. Thus, today's (5/18) high temperature will be reported in tomorrow's (5/19) observation. This record, for reference, is 92 degrees set in 1962. --------------------------------------------- Abnormally warm temperatures will continue on May 19th, thus multiple sites could challenge daily record high temperatures. Daily Maximum High Temperatures for May 19th: * Harrisburg: 95F set in 1962 * Williamsport: 96F in in 1996 * Altoona: 92F set in 1996 * Bradford: 85F set in 1962 * State College: 92F set in 1934, tied in 1996. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ WHAT HAS CHANGED...Lambert/Steinbugl/Bauco KEY MESSAGES...Lambert/Steinbugl/Bauco DISCUSSION...Lambert/Steinbugl/Bauco AVIATION...Bowen CLIMATE...Beaty