514 FXUS61 KCTP 300603 AFDCTP Area Forecast Discussion National Weather Service State College PA 103 AM EST Tue Dec 30 2025 .SYNOPSIS... * Gusty winds and lake effect snow showers will bring hazardous travel to Central PA today and Tuesday. * A weak clipper system will bring light snow to western PA Tuesday night. * A more significant system will bring several inches of snow to locations west of US-219 on New Years Eve along with a threat of snow squalls along an Arctic cold front. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... KEY MESSAGES: - Temperatures will continue to plummet overnight as wind gusts push wind chills into the single digits to low teens by Tuesday morning. - Frequent wind gusts over 40mph are expect this evening and overnight, with high end gust potential over 60 mph in the Laurel Highlands. - Significant lake effect snow accumulation is expected over northwest PA. -------------------------------------------------------------- In the wake of this morning's front, strong low- level cold advection is ongoing, along with very windy conditions. Many locations have already recorded gusts over 45 mph. Although the strongest isallobaric forcing is progged over upstate NY and southern Canada, very impressive pressure rises, good post- frontal downward momentum transfer, and an overall strong wind field into the upper part of the boundary layer across PA, argue for widespread wind gusts of 40-50 mph, and isolated gusts of 55-65 mph over the Alleghenies and points just downstream. A High Wind Warning remains in effect for several of our Western and SW zones, with a Wind Advisory for the rest of the area. The period of strongest winds is anticipated to continue through the evening hours, when BUFKIT Time/Height cross- sections show the 60 kt wind contour as low as 1000 ft AGL and within the lower third of the well-mixed Blyr. This is almost a slam dunk for 50 kt gusts across the Warned Area. After morning highs in the 40s-mid 50s, temperatures are currently in the teens across the northwest mountains and will continue to plummet tonight. Frigid wind chills will also become an issue tonight and Tuesday morning in particular (apparent temperatures +/- single digits). These values don't quite reach cold weather headline criteria (-10F). As of 3PM this afternoon, the leading edge of stronger snow showers/squalls is just pushing into northwest PA. Southwesterly wind gusts will veer around to westerly or northwesterly this evening, helping steer lake effect snow bands into Central PA. 75th to 90th percentile snowfall totals (a good bet where the most persistent bands reside) argue for 3-8" of snow from northern Warren into northwest McKean county, where a Winter Storm Watch was upgraded to a Lake Effect Snow Warning. A favorable fetch off the lakes along with upslope effects should support efficient snowfall accumulation in the Laurels through Tuesday afternoon as well. Have hoisted a Winter Weather Advisory for Elk down to Somerset for the potential of a few inches of snow along with blustery winds and reduced visibility in blowing snow. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... Snow showers and areas of more persistent, heavier LES will continue into Tuesday with the deep cloud layer occupied by the favorable DGZ of -12 to -18C. As the parent surface low pressure system lifts northeast, the surface pressure gradient will wane on Tuesday afternoon, resulting in slackening winds into the evening. We also expect a lull in snow showers by Tuesday afternoon. It will be a brisk day on Tuesday with high temperatures in the upper teens to near freezing and wind chills shaving about 10-12 degrees off of those thermometer readings. Hi-res guidance depicts a compact shortwave drifting southeast across western PA on Tuesday evening into Wednesday morning. This will bring additional, mainly light, snowfall accumulation to locations west of US-219. A local enhancement of snow in the northwest mountains could also necessitate a short-fused Advisory, but impacts should be fairly limited. In the wake of the shortwave, winds shift around to a more westerly fetch, which would also direct lake effect snow bands into NY as opposed to Warren County. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... On the large-scale, a cold, cyclonic NW flow pattern will reside over much of the eastern CONUS this period, underneath a deep upper low in eastern Canada. On Wednesday afternoon (New Years Eve), a wave of low pressure will drift eastward across the Great Lakes, and drag an Arctic front south through the Commonwealth. Underneath a favorable left exit region of an upper jet, this front could produce a threat of snow squalls late Wednesday evening into the New Year. Anyone planning to travel for the New Year should be prepared for the risk of snow squalls. If a Snow Squall Warning is issued, delay travel or exit the highway at the next opportunity. A snow squall produces blizzard-like conditions with gusty winds, heavy snow, and significantly reduced visibility. In addition to the threat of snow squalls, fairly robust moisture associated with this system will bring a more potent batch of snow to the region. Snowfall totals over 4" are possible west of US-219 with localized amounts >6" in the higher elevations of western Somerset County as well as in the typical lake effect zones of northwest PA. A Winter Storm Watch is now in effect for Somerset County from 4PM Wednesday through 10AM Thursday for the significant snowfall potential on the western ridges. Additional Watches/Warnings may be needed in northwest PA along with advisories along the spine of the Alleghenies if confidence continues to increase. In the wake of this system, a reinforcing shot of arctic air later Thursday into Friday should support wind chills in the single digits and teens once again. Then, temperatures should gradually moderate this weekend, as heights aloft slowly start to build. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... Current radar outlines lake effect snow showers continuing throughout the northwestern half of the forecast area, with restrictions most likely at BFD/JST/AOO/UNV in the near-term through ~12Z Tue. There remains a non-zero chance and IPT sneaking in brief periods (~30-45 minutes worth) of IFR as snow showers make a close approach to the airfield between 06Z-10Z Tue; however, confidence remains too low (~20%) to include mention in the 06Z TAF package. A combination of HREF/NBM model guidance has been implemented for lake effect and upslope snow mentions, with highest confidence at BFD/JST based on recent observations and current radar trends. HREF probabilities in snow at AOO/UNV begin to decrease in the 06Z-12Z TAF period so higher (~50-60%) confidence on mentions being removed from the TAFs after ~09Z Tue. Gusty winds currently being observed will stay consistent overnight with ENS guidance suggesting a potential (slight) uptick in winds through 12Z. Winds remain mainly unidirectional with height; however, an increase of ~40kts between 925mb and 850mb will bring about some low-level speed shear throughout the overnight hours through 12Z Tue, especially at JST/BFD/AOO/UNV before potential decreases after sunrise. Gusty winds gradually taper off between 12-18Z Tue with high (~80-90%) confidence in gusts across the entire area dropping below 30kts by 18Z Tue. Outlook... Wed...Chance of snow showers across the north and west, dry southeast. Thu...Chance of snow showers. Fri...Mainly dry. Slight chance of a snow shower at BFD. Sat...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... Wind Advisory until noon EST today for PAZ004>006-010>012-019- 026>028-035>037-041-042-045-046-049>053-056>059-063>066. Lake Effect Snow Warning until 4 PM EST this afternoon for PAZ004-005. Winter Weather Advisory until 1 PM EST this afternoon for PAZ010-017-024-033. High Wind Warning until 4 PM EST this afternoon for PAZ017-018- 024-025-033-034. Winter Storm Watch from Wednesday afternoon through Thursday morning for PAZ033. && $$ SYNOPSIS...Jurewicz/Lambert/Banghoff NEAR TERM...Jurewicz/Lambert/Banghoff SHORT TERM...Jurewicz/Lambert/Banghoff LONG TERM...Jurewicz/Banghoff AVIATION...NPB