


Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
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381 FXUS61 KCTP 160925 AFDCTP Area Forecast Discussion National Weather Service State College PA 525 AM EDT Thu Oct 16 2025 .SYNOPSIS... * Seasonably cool days and crisp Autumn nights through Friday * Modest warming trend/above average temperatures this weekend * Weekend starts dry and ends wet: breezy/windy conditions and locally heavy rain showers probable Sunday into Sunday night && .NEAR TERM /THROUGH TONIGHT/... Mostly sunny and seasonably cool/breezy today. Max temps in the low 50s to low 60s are near to several degrees below mid October climo. Daytime dryness will peak this afternoon with minRH in the 25-35% range. P-gradient and strong northerly llvl flow between exiting storm in the North Atlantic and high pressure migrating to the southeast from the Upper Great Lakes will result in 20-30 mph wind gusts focused over the eastern portion of the forecast area. Minimum temperatures will reach a short term nadir overnight with frost/freeze conditions probable across the majority of CPA early Friday morning. Fcst low temps range from 25F in the usually colder spots in the NW Alleghenies to around 40F in the Harrisburg metro. Frost advy has been issued for the 7 zones in the LSV where the growing season remains active. A persistent light NNW breeze raises some concern for frost formation especially in the eastern periphery of the CWA adjacent to PHI, but overall risk/confidence is high enough to issue particularly for the valley locations and sheltered rural/agricultural areas (outside of the larger cities and towns) that should experience the coldest temperatures. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Sfc ridge axis migrates slowly eastward Friday reaching eastern PA by 12Z Saturday. This should allow for one more chilly night particularly in the eastern/northeastern valleys. Max temps are neutral to slightly warmer day/day with fcst highs 55-65F. High to mid level clouds will steadily increase from west to east Friday night into Saturday as WAA pattern ramps up heading into the weekend. 500mb ridge axis shifts to the east on Saturday with milder air surging into the area behind an increasingly strong SSW 850mb LLJ. Lead perturbation in the Upper OH Valley could trigger some showers across western/northwestern PA early on Saturday in the vicinity of lifting warm front. Otherwise, it will be a dry and milder start to the weekend with highs +5-10 degrees warmer vs. Friday. Amplifying 500mb trough digging into the mid MS/lower OH valley Saturday night will send a deepening/seasonably strong sub-1000mb sfc low into lower MI by 12Z Sunday. Low level wind fields strengthen in-kind and advect hi pw air >1" northeastward from the Gulf. Blended model guidance favors increasing odds for rain showers over the NW 1/2-1/3 of the forecast area overnight Saturday through early Sunday morning. Noticeably milder readings Saturday night with low temps trending +7-15 degrees warmer vs. Friday night thanks to increasing clouds and southerly flow. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 16/00Z model guidance still not in full agreement concerning the evolution of the sharpening/negative tilted upper trough pushing east from the Great Lakes/Ohio Valley Sunday into Monday. The EC remains the most amplified solution, showing a deep 500mb cut- off low over PA by 12Z Monday. The GFS is much flatter and more progressive with the CMC clustering closer to the GFS albeit a tad stronger/farther south. As the pattern details are ironed out with time, there are some signals flashing for potential isolated svr storm/heavy rain threat Sunday-Sunday night. The tightening p-gradient and strong llvl wind fields with this system will also bring breezy/windy conditions which could easily blow around unsecured objects including Halloween decorations. At a minimum, rain showers should linger into Monday followed by a drying trend Monday night into Tuesday. Time of arrival of the next frontal system for Tue-Wed also in question and is largely dependent on the speed/departure of the Sun-Mon system. EC is again on the deep end of the guidance envelope; max POPs into midweek are painted across the western & northern mtns. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... 515 AM update. Winds have weaken overnight, but expect winds to quickly pick back up shortly after sunrise. Otherwise not really much change. Had updated BFD earlier, tiny area of lower clouds there earlier. Earlier discussion below. Winds kicking up at times since I came in at 1130 PM. Adjusted the fcst for this. Also the evening forecaster had LLWS in for some eastern areas. Anyway, expect clear skies with VFR conditions today into Friday. Main issue today will be gusty winds once sun is up here this morning. Main change was to go a bit stronger with the winds than the 00Z TAF package had, or the guidance. This based on the pressure gradient being a bit stronger today, than earlier. Winds will once again weaken some after sunset today. Next chance for widespread showers will be Sunday, as a cold front nears the area. Outlook... Fri-Sat...VFR. Sun-Mon...Restrictions possible in SHRA. Low probability of a thunderstorm over northwest PA. && .CTP WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 2 AM to 9 AM EDT Friday for PAZ036-057-059- 063>066. && $$ SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Steinbugl LONG TERM...Steinbugl AVIATION...Martin