textproduct: State College

WHAT HAS CHANGED

Frost advisory tonight.

KEY MESSAGES

1) Another cold night in store for central PA. Frost Advisory in place for some of our Eastern Counties.

2) Extended stretch of dry and seasonal Fall weather this week, followed by a chance of rain on Sunday into Monday.

DISCUSSION

KEY MESSAGE 1: Another cold night in store for central PA.

High pressure will slide east overnight, with winds shifting around to the SW across west central PA. This should make frost less likely tonight in the places that were coldest this morning. However, temperatures will be cool enough to support patchy fog for the northern tier and Susquehanna valley.

A frost advisory is in place for the portions of Eastern PA in the Middle Susquehanna Valley where conditions are expected to line up the best for frost. The northern tier will likely be cool enough for frost but an approaching upper level wave will induce some southerly surface winds ahead of a cold front overnight. These winds will likely preclude widespread frost formation. The Lower Susquehanna River Valley will likely be too warm for widespread frost formation. Both areas though will likely see some degree of patchy frost, particularly in low lying valleys.

------------------------------------------------------------- KEY MESSAGE 2: Extended stretch of dry and seasonal Fall weather this week, followed by a chance of rain on Sunday into Monday.

High confidence in a prolonged stretch of dry and seasonable Fall weather this week. Expect cool nights and refreshing afternoons with low humidity through Saturday. A tropical disturbance in the gulf will move up north towards the Ohio River Valley this weekend bringing tropical moisture and rain potential Sunday afternoon into Monday. This system looks fairly progressive as it begins to get absorbed into some strong westerly flow in Canada. However, robust forcing and PWATs in the 1.5-1.75" range, particularly in the southern tier of the state, may yield some periods of heavy rain. Uncertainty remains regarding how this disturbance plays out.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

Mostly clear skies, light winds, and cool conditions will be the story tonight. High pressure is in control over central PA and VFR flight conditions will be predominant over the region for the next 24 hours. While there are good conditions tonight for radiational cooling, fog is not expected due to the winds tonight preventing formation. A few high clouds could slide into the area tomorrow afternoon from the northwest, but no restrictions or impacts are anticipated. There is a <20% chance KBFD will see an isolated light rain shower Wednesday afternoon after 22Z, but outside of that everything should remain dry through the next several days.

Outlook...

Thu-Sun. VFR conditions expected.

CTP WATCHES/WARNINGS/ADVISORIES

Frost Advisory from 11 PM this evening to 9 AM EDT Wednesday for PAZ049>053-058.