textproduct: State College

WHAT HAS CHANGED

* No significant changes

KEY MESSAGES

1) Frost/freeze conditions are probable Monday night and Tuesday night

2) Not much rain expected for the first 10 days of October

DISCUSSION

KEY MESSAGE 1: Frost/freeze conditions are probable Monday night and Tuesday night

Aside from varying amounts of mainly mid level clouds with some virga across our SE zones skies were mainly clear near and to the north of the Interstate 80 corridor with some patchy valley fog developing across the Northern Mtns where air/waters delta Ts were 20 deg F or more.

Noticeably cooler/drier air already filtering into CPA with dewpoints in the 40s, to low 50s in the SE. This lead to a refreshingly crisp start to the 1st weekend of October with abundant sunshine and low humidity.

The coldest air of the early Autumn season is poised to arrive by early next week with frost/freeze conditions expected Monday night and Tuesday night over much of the forecast area. Locations to the northwest of I-81 have the highest odds for frost with min temps around the freezing mark in the northern tier. ------------------------------------------------------------- KEY MESSAGE 2: Not much rain expected for the first 10 days of October

The cold front that brought clouds and some periods of light rain to the region on Friday has become nearly stationary early today from the Interstate 81 corridor in Virginia to the Delmarva Coast.

Variable amounts of clouds will persist across Southern PA today with nothing more than a few light sprinkles possible. Abundant sunshine, a 5 to 10 mph North to Northeast wind, fairly low humidity in the 30s and 40s this afternoon, excellent visibility and near normal high temperatures will kick off this first weekend on October across Central and Northern PA.

A fast-moving and amplifying trough moving our way from the Northern U.S. and South-Central Canada will bring a periods of increased moisture and cloud cover for Sunday into Sunday night across much of Central and Southern PA with a likelihood of some light rain, thanks to periods of modest meso-B uvvel associated with the right entrance region of several jetlets moving over, or just to the north of PA.

The best chance for light rainfall amounts of several hundredths, up to one tenth of an inch will be across portions of the Lower Susquehanna Valley and adjacent Southeastern PA. Elsewhere across the Central Ridge and Valley Region of the state, the Laurel Highlands and Northern Mtns, there may be just enough rain to wet the ground at times but only measure a few hundredths of an inch.

Outside of this narrow window for light precip, expect a prolonged dry stretch to last through next week as a large area of Canadian high pressure dominates the pattern.

AVIATION /07Z SATURDAY THROUGH WEDNESDAY/

Winds take on a northwesterly/northerly flow pattern behind the front as drier air filters in. The band of mid to high level clouds stretching from southwest to northeast will be mostly gone by morning leaving clear skies in its wake.

Patchy fog is possible at KBFD and KIPT by daybreak on Saturday, but there is not enough confidence to prevail any restrictions there. Fog may be more likely at KBFD as clouds have cleared out quicker than at KIPT. Some light valley fog is being noted on Satellite around BFD around 05Z which will be watched for any amendments should it reach BFD. An otherwise pleasant day is expected on Saturday with high clouds moving to the south of the area and mainly sunny skies across PA.

Outlook...

Sun...Restrictions possible as a weak low pressure system develops along the residual frontal boundary over the Mid- Atlantic. -RA possible, more so across southern and eastern PA.

Mon...Dry conditions with VFR prevailing. AM fog possible.

Tue-Wed...Dry conditions with VFR prevailing. AM fog/frost possible, especially across the Allegheny Plateau and Laurels.

CLIMATE

September 2026 precipitation rankings

IPT: 11th wettest (6.84") MDT: 26th wettest (4.72") AOO: 9th wettest (5.58") BFD: 10th wettest (4.85") JST: 3rd wettest (7.31") *since 2000 STC: 6th wettest (7.90")

CTP WATCHES/WARNINGS/ADVISORIES

None.