textproduct: State College

SYNOPSIS

* Rain and a few thunderstorms Saturday afternoon into Saturday night; a strong/severe storm possible along/west of US-219 * Windy and colder with lake effect snow bands Sunday into Monday; changing road conditions/hazardous travel possible * Light rain/snow possible in the southern tier Tuesday followed by a slightly milder/dry trend through the middle of next week

NEAR TERM /UNTIL 6 AM SATURDAY MORNING/

Model signals yesterday for more clouds was on point; there may even be a few sprinkles over the eastern third of the CWA. Limiting factor is very dry air near the sfc with dewpoints falling through the 20s during the day. If cloud trends continue to be persistent, min temps may end up being at least a few degrees too cold on the margin. Followed earlier signal for some clearing across the NW Alleghenies which would favor some areas of advective fog late tonight into early Saturday morning.

SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/

Rain/showers spread southeast Saturday afternoon through Saturday night ahead of cold front. Although smaller-scale developments remain uncertain, latest model output offers little change to prior runs concerning the large-scale pattern evolution Saturday through Saturday night. There remains a low end risk for a few stronger storms over western PA into the Allegheny Front vicinity; SPC has maintained a MRGL risk SWO that covers locations along and west of US-219.

Pattern turns windy and blustery behind the cold front late Saturday night through Sunday. Wind gusts 30-40+ mph are definitely in the cards with potential for advisory criteria. The increasingly strong west-northwest flow will develop across the Great Lakes and open up the potential for lake effect/upslope snow into the interior of CPA Sunday afternoon through Sunday night. Specifically, a multi-lake connected snowband or bands is trending more likely to probable based on the latest higher res model guidance extending from Lake Superior/Huron across Erie into northwest PA. Probabilities are at least 50/50 for advisory level snow accum especially in more persistent NW flow trajectory bands. There may also be an emerging signal for some squalls or very long fetch bands perhaps extending as far southeast as the I-81 corridor.

We were keen to message the multitude of potential hazardous weather concerns over the weekend in ranked order of confidence (high to low):

-strong (non-tstm) wind gusts >40mph -lake effect snow accumulation north of I-80 & west of US-219 -heavy snow bands or squalls -strong thunderstorm wind gusts >50 mph

With rain prior to the cold blustery winds and snow, treatment on roads may be challenging.

LONG TERM /MONDAY THROUGH FRIDAY/

Snow showers and gusty wind continue on Monday and gradually taper off Monday night.

Models show the next system for early next week ejecting out of the central Plains (NE/IA/KN/MO vicinity) as a flat/compact southern stream shortwave and weak sfc low tracking eastward through the Ohio Valley toward the DelmarVA. Ensemble data keeps the bulk of precip and max POPs with this system along and south of the MD line centered on next Tuesday. Any shifts in the track or speed/timing could introduce some ptype issues on the northern edge of the precip. That said, this system could also skirt by far enough to the south and not bring any precip to CPA.

High pressure edging southeast from the Great Lakes appears deliver a dry period around midweek/Wednesday before precip odds trend higher into the end of next week. This pattern setup again favors a potential overrunning rain/mixed ptype scenario.

AVIATION /03Z SATURDAY THROUGH WEDNESDAY/

Low clouds are gradually clearing from northwest to southeast this evening with VFR conditions areawide. High clouds will move in ahead of our next system. Some patchy fog is possible tonight, but shouldn't impact any airfields.

On Saturday, a strong, fast moving low will move down the Saint Lawrence River Valley. Moisture will increase during the day, with a gusty wind developing. A few light showers are possible in the morning and early afternoon, but the majority of showers should hold off until the late afternoon and evening. Ceilings will lower during the day Saturday from west to east, with IFR likely at BFD and JST, MVFR at AOO, UNV, and IPT, and VFR prevailing at LNS and MDT.

Winds will turn more gusty out of the northwest Saturday night and Sunday in the wake of a cold front. Restrictions are likely at BFD and JST, with impacts possible farther southeast in lake effect snow bands that take aim at any airfield.

Outlook...

Sun...SHRA/SN esp NW half. IFR poss. Windy.

Mon...Isold/SCT SHSN NW. Windy.

Tue...SHRA/SN possible early, otherwise dry.

Wed...Mainly dry.

CTP WATCHES/WARNINGS/ADVISORIES

None.