FXUS61 KCTP 150924 AFDCTP Area Forecast Discussion National Weather Service State College PA 524 AM EDT Wed Apr 15 2026 .WHAT HAS CHANGED... * Additional details on today's thunderstorm threat && .KEY MESSAGES... 1) Summerlike warmth visits the region this week with near-record daily maxes and daily mins on tap for today and tomorrow. Elevated risk of wildfire spread poss Thu. 2) Several periods of showers and thunderstorms expected during the next few days, with the greatest amount of rainfall likely occurring across northern and western PA. Some storms may be severe, particularly across the northwest late this afternoon and evening. && .DISCUSSION... KEY MESSAGE 1: Summerlike warmth visits the region this week with near-record daily maxes and daily mins on tap for today and tomorrow. Elevated risk of wildfire spread poss Thu. A +2 sigma ridge over the Southeastern US will continue to drive warm air up into the Mid Atlantic and Northeastern US. Temps as of 09z in the 50s and low 60s are still sitting a degree or two above the minT records at IPT and MDT. Record warmth will remain possible through Friday morning. Humidity has accompanied the heat thus far, with dewpoints in the upper 50s and 60s expected again this afternoon. The flow on Thursday will become more SWrly, with more large scale downsloping off the Appalachians resulting in drier air at low levels. RH values in south central PA may dip into the low 20s pct Thu afternoon, which, combined with wind gusts over 20 mph, may result in an elevated risk of wildfire spread, particularly if that area remains rain free today/tonight. We will say goodbye to the warmth for a while come Sunday after a strong cold front knocks temps back to near the freezing mark for the start of next week. ---------------------------------------------------------- KEY MESSAGE 2: Several periods of showers and thunderstorms expected during the next few days, with the greatest amount of rainfall likely occurring across northern and western PA. Some storms may be severe, particularly across the northwest late this afternoon and evening. A decaying MCS moving from Lake Erie into NW PA has produced wind gusts near 40 kts on the Erie lakeshore. As this system moves east, multiple lines of convection may initiate early this morning as waves in the top of the stable nocturnal boundary layer lift parcels high enough to tap into a few hundred J/kg of elevated instability. Sfc wind gusts will likely be less than 30 kts for most places given the stable sfc layer. This first round of convection will be winding down by 10-11 AM, with a lull in the action expected late morning into early afternoon. This afternoon and evening, new convection is expected to initiate along a west-east quasi stationary boundary and remnant outflow boundaries. Cool temps at mid levels above very warm and moist low levels will result in steep lapse rates with SBCAPE progged above 1000J/kg across much of central PA. With about 30-40 kts of 0-6 km bulk shear, discrete cells and clusters/linear segments will be possible. Storm motions near 40 kts and DCAPE of 500-700 J/kg should be sufficient to produce a respectable threat for damaging winds in the NW this evening. There is also some potential for training convection later this evening into tonight over NW PA as the mean flow becomes aligned with WSW-ENE initiating boundaries and moisture continues to advect in from the SW. Convection allowing models suggest there could be a few stripes of 1-3" of rain across NW PA in areas of repeated heavy rainfall. WPC continues a MRGL ERO for this threat. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... A relative minimum in thunderstorm activity is expected through the rest of the night, with only a few showers/isolated thunderstorms showing up on radar as of 06Z. These should largely stay away from any TAF sites, but may get close to UNV. Light winds along with some breaks in the clouds has allowed for locally dense fog to develop across parts of Central PA, and IFR/LIFR conditions are expected at BFD and IPT for much of the night. Confidence is low on visibility restrictions developing anywhere else. LLWS is expected at JST, AOO, and possibly UNV for the rest of the night with a 40 knot low-level jet overhead. An ongoing MCS over Michigan will bring the next round of thunderstorms to the region early this morning. These thunderstorms will weaken as they approach the area, but will enter northwest PA around 11Z. BFD and JST are most likely to see showers and thunderstorms as this line moves through. Conditions should improve to VFR through the morning behind this line for all of Central PA with mainly dry conditions and scattered mid and high clouds. West-southwesterly winds will be sustained at 10 to 15 knots with gusts to 25 knots. Another round of showers and thunderstorms is expected late this afternoon and into the evening. These storms will be capable of producing strong wind gusts, potentially in excess of 40 knots. Northern and western TAF sites are most likely to see showers and storms later today. Fog formation is possible as rain moves out of the area Wednesday night, with BFD and IPT again being the most likely to see fog. Outlook... Thu...VFR most of the time, but brief restrictions possible in hit and miss showers and thunderstorms, mainly across the north and west. Fri...Restrictions possible early, then improving to VFR in the afternoon. Sat-Sun...Restrictions in SHRA possible. && .CLIMATE... Record high daily maxes and mins are possible this week as summerlike warmth visits the region. Here's a look at the records as they stand right now, with a * indicating that the forecast is equal to or greater than the record. Record High Daily Max / Daily Min... For Harrisburg: April 15: 87* (1941) / 61* (2023) April 16: 89 (2002) / 63* (1941) April 17: 91 (2002) / 60* (2002) For Williamsport: April 15: 86 (1994) / 57* (2023) April 16: 90 (2002) / 55* (2023) April 17: 91 (2002) / 58* (1896) && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ WHAT HAS CHANGED...Colbert KEY MESSAGES...Banghoff/Colbert DISCUSSION...Banghoff/Colbert AVIATION...Bauco CLIMATE...Colbert