Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
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575 FXUS61 KCTP 300954 AFDCTP Area Forecast Discussion National Weather Service State College PA 454 AM EST Sun Nov 30 2025 .SYNOPSIS... * A quick-hitting system will bring light to moderate snow (north), a wintry mix (south), and breezy conditions. Freezing drizzle is possible in the Laurels. * A brief period of lake effect snow may affect the far NW Sunday night. * A more widespread/significant winter storm is expected on Tuesday. && .NEAR TERM /THROUGH TONIGHT/... Radar imagery this morning looks much more ominous than conditions at the surface indicate, in large part due to very large dewpoint depressions and remarkably dry air at the surface. A line of warm advection rain/snow showers is approximately parallel to I-99 and will continue to drift slowly northeast over the next few hours. Only light snow accumulation is expected across the Laurels and northern mountains. The primary concern is freezing drizzle occurring on the higher elevations of the Laurels. Model soundings indicate a thick cloud layer of super- cooled liquid water there before sunrise. Temps will be below freezing there despite the thickening clouds. Without (many) snow crystals in the cloud, the more- likely precip type is freezing drizzle. The forcing and upslope flow are poor and non-existent, respectively. It is even more of a downslope flow, esp for Cambria and Bedford. A WW.Y remains in effect until 12PM today for light ice accum at the highest elevations. A cold front will sweep through the CWA from W to E during mid- day, bringing a renewed and perhaps notably uptick in intensity of snow/rain showers. The better lift and instability will be over the NW, and they could get above freezing just before the front arrives. Almost all other locations will likely get to or above freezing, too. The soundings look like snow N of a line from JST-UNV-IPT before the front passes despite the above freezing air temps. Therefore, there could be some heavier snow showers or squalls that could ice up the previously warmed roads/bridges. The highest risk for SQWs would be over the Alleghenies where the SNSQ parameter start to light up as we see some instability develop in the "warm" sector. The vertical profiles look more like mix or rain as you move farther south toward I-81, especially the later in the day things arrive/occur. Maxes will be in the 40s S of I-80 and below 1500ft. For now, only mentions of SNSQ will be in the NW third. FROPA 18Z BFD, 22Z IPT/AOO, 00Z at LNS. Wind will get gusty in the unstable/mixed air, but should be under 30KTs. Some hilltops in the west could get into the 30s. The flow behind the front goes NWrly and still has some kick. Lake effect snow will resume Sunday afternoon and continue overnight coincident with a secondary cold front pushing thru the NW. An additional inch or two of snow is possible in far northwest PA with light accumulations possible down to I-80. Moisture decreases and inversion lowers by sunrise Monday. && .SHORT TERM /MONDAY THROUGH TUESDAY/... Monday should be bland/fair with high pressure arriving and centering overhead. Clouds will probably linger in the W very much like today (Sat) before high clouds move in later in the day on Monday. A few high resolution models keep a lake effect snow band going into late morning west of I-99, but building high pressure should limit any impacts. Another storm will approach the region on Tuesday as cold air in the middle of the country sets up a strong baroclinic zone over the eastern US. High pressure in the Plains should keep cold air in place on the northern side of the precipitation shield from a wave of low pressure progged to move out of the Gulf. This system should move northeast around the base of the aforementioned high pressure system, bringing increasing moisture to the Mid- Atlantic Monday night into Tuesday. The system at this time looks to be somewhat progressive with the lack of a strong area of high pressure to slow the advance of the system. Despite the expected fast forward movement, a deepening coastal low could still provide enough forcing juxtaposed with favorable upper jet dynamics to produce significant snowfall across the region. Snow looks to arrive later Monday night and lift across the region during the day on Tuesday. The eventual track and intensity of the low will have big implications on observed snowfall totals and the northward extent of any mix/rain scenarios. The latest WPC probabilities of 0.25" or greater liquid equivalent snow/sleet paint medium probabilities (40-70%) across most of the region, with slightly lower amounts expected in northwest PA. The latest Winter Storm Outlook highlights a 30-50% chance of Warning criteria snowfall (5"+) in northeast PA, primarily east of US-15. GEFS and ECENS probabilities of 6"+ have trended up a bit also supporting the 30-50% probability in the Poconos, with an even higher likelihood up through coastal New England. If the current track/timing holds, watches may be needed in the next forecast cycle. At this time, though, a plowable snowfall seems like a reasonable bet for most of the region. Guidance has remained consistent overall for snowfall amounts with the last two runs, however some uncertainty remains whether or not warm nosing above the surface could limit snow across the PA/MD border. If mixing is a problem for anywhere in Central PA, it would be for locations southeast of US-30 in York and Lancaster County. Continue to monitor the forecast in the days ahead, especially if you have plans to travel. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Precipitation moves east of the area by Tuesday evening, with perhaps a bit of lake effect or upslope snow into Wednesday morning. High pressure builds Wednesday with a reinforcing cold front moving through Wednesday night into Thursday. This could produce some light snow across mainly the northern tier. Thursday night and Friday look quite chilly, with lows in the single digits and teens while highs only make it into the 20s to low 30s. Otherwise, temperatures will be fairly consistent for the upcoming week and weekend, with highs in the 30s and lows in the teens and 20s. By next weekend, another storm system looks to affect the Midwest and northeast US. Considerable uncertainty remains with the low track of this system. A track northwest of PA would lead to snow changing to a wintry mix and rain, while a track southeast of PA could look pretty similar to Tuesday`s system with primarily snow. Regardless, a prolonged stretch of cooler than normal temperatures and an active storm track through the northeast looks to continue into the first week (and more) of December. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... Some radar returns across north/western Pennsylvania are likely struggling to reach the ground in the near-term with low- level dry air in place. Better chances for precipitation come after 06Z Sunday based on a consensus of GLAMP/HREF guidance, thus have trended back any mentions of precipitation at BFD until after 06Z Sunday. Snowfall will begin with restrictions to MVFR/high-end IFR at BFD as there remains some uncertainty with respect to how east the heaviest band of snowfall will extend between 06-08Z Sunday. There remains a lower probability solution where the heavier band sneaks into BFD closer to 07Z and brings (V)LIFR restrictions; however, confidence remains too low (~20-30%) to include in the 00Z TAF package and might be better resolved in the 06Z TAF package with current radar trends available at that time. Precipitation is expected (based on GLAMP/RAP/HREF guidance) to enter JST/AOO closer to the 11-12Z timeframe and gradually extend eastward with prevailing MVFR restrictions limited to JST/AOO/UNV at this time. There remains a lower confidence solution where lower ceilings develop at IPT (~30% probability) so have outlined a PROB30 group for this outcome. IFR restrictions after 12Z will look confined to western terminals (BFD/JST) for the 00Z TAF package. Moderate-to-high (~60-70%) confidence in LLWS exists at all airfields outside of UNV/IPT/MDT/LNS after 11Z with the cold frontal passage and increased low-level flow behind the frontal passage across central Pennsylvania. Recent TAF package continues mentions for these restrictions, with slight timing adjustments based on RAP/GLAMP model guidance. Outlook... Mon...Mixed/wintry precip likely early on. MVFR likely. IFR possible. Tue...Snow possible, before a possible mix later in the day across the south. Restrictions possible. Wed-Thu...Trending drier, lingering snow across NW PA. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon EST today for PAZ033. && $$ SYNOPSIS...Banghoff NEAR TERM...Banghoff SHORT TERM...Banghoff LONG TERM...Banghoff AVIATION...NPB