


Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
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033 FXUS61 KCTP 011617 AFDCTP Area Forecast Discussion National Weather Service State College PA 1217 PM EDT Tue Jul 1 2025 .SYNOPSIS... * Increasing threat for damaging winds and heavy rainfall this afternoon; significant flash flooding impacts possible * Drier/less humid/more comfortable conditions are likely for mid to late week with a high confidence of dry weather with seasonable temperatures on Independence Day * Trending warmer and more humid this weekend; unsettled pattern returns by Sunday && .NEAR TERM /UNTIL 11 PM THIS EVENING/... Severe T-storm threat via SPC MCD #1529 Convection is building to the east across southwest into south central PA at midday ahead of a low-amplitude shortwave trough that is progressing east across the Upper OH Valley. While there is some near-term uncertainty of how quickly this initial activity will strengthen amid weak DCAPE, the downstream airmass is destabilizing quite well with sfc temps into the mid 80s. This will yield an uptick in convective intensity as clusters impinge on richly moist airmass where 70-75F surface dew points are pervasive. Although lower-level winds will remain weak and predominately veered, moderate mid to upper-level westerlies will support organized multicells capable of producing multiple strong to isolated severe gust swaths. Scattered damaging winds appear likely towards mid to late afternoon. A severe tstm watch is likely to be issued by 17Z/1PM. Flash Flooding: FF threat remains locked in across south central and southeast PA. 12z IAD sounding came in with daily record pwat of 2.07" along with a daily record WBZ 0 height supporting a very deep warm-cloud layer within the lower troposphere. This environment along with tall/skinny CAPE profiles are highly representative of a strong prospect for not only heavy rain, but significant rate driven cores (2-3+ in/hr) that can efficiently drop several inches of rain in a very short span of time. The potential magnitude of rain/rates combined with very saturated antecedent conditions with locally 4-6" in some spots in the past 24 hrs suggest significant flash flooding impacts are possible. From a historical perspective, the WPC moderate risk of excessive rainfall (risk level 3 out of 4) typically only occurs 5-6x a year in PA, and this is the second MDT risk in the past 30 days. WPC should send a new MPD with more details shortly. Shower activity slowly shifts to the southeast tonight with any post frontal clearing expected to result in fog formation into Wednesday morning. && .SHORT TERM /11 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... The front seems like it should be clearing the SE late this evening, perhaps around midnight. Thus, the precip should be tapering off then. The clearing anticipated behind the precip will probably cause fog, especially in the central mountains where they won`t have time to dry out like the NW may. Cross- lake flow may introduce a couple of showers over the NW early tonight. Dewpoints only dip to around 60F in BFD, but 60+ numbers remain across the rest of the CWA through morning. Most everyone will get down to their dewpoint by morning. Have added a bit more fog to the forecast for tonight. Wed looks like a fair and warm summer day. The gradient isn`t very strong behind the front, so the wind should be under 10MPH out of the NW. maxes generally 80-85F, with a deg or two variancein the normal cool (elevations) and warmer (urban) spots. There is a small (20 PoP) chance for a shower over the far SE. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure begins to build southwest of the region, providing fair weather for the middle of the week and into the weekend. Best chances for precipitation through Saturday will remain due to a cold frontal passage across the northern half of Pennsylvania. Cold front remains relatively moisture-starved; however, generally think forcing will be enough to cause a shower and afternoon/evening thunderstorm. The biggest feature of the post-frontal airmass will be much lower dewpoints and refreshing nights/mornings. There is high confidence in lows dropping into the 50s and low 60s Thursday and Friday nights, which will be a significant and welcome change from the long-duration heat/humidity we have experienced over the past few weeks. Independence Day activities should be under fair skies, comfortable temperatures, and pleasant northwest winds. Low pressure approaching the Great Lakes by Sunday morning will bring about increasing chances for precipitation for the second half of the weekend and into the beginning of next week. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... Another round of t-storm impacts expected this afternoon across CPA airspace. Fog will be a concern tonight into early Wednesday morning. Outlook... Wed...AM fog, then VFR. Thu...Primarily VFR; stray PM shower/t-storm possible. Fri-Sat...AM fog possible; otherwise VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... Flood Watch until 11 PM EDT this evening for PAZ036-057-059- 063>066. && $$ SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Dangelo LONG TERM...Banghoff/NPB AVIATION...Steinbugl