textproduct: State College

WHAT HAS CHANGED

* No major changes

KEY MESSAGES

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

2) Little to no rainfall forecast through Saturday, October 10th

DISCUSSION

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

The coldest air of the early Autumn season will push southeast into Central PA early in the upcoming week with frost/freeze conditions expected Monday night and Tuesday night over at least the NW half of the CWA, with min temps around the freezing mark across the Northern Tier counties of PA.

------------------------------------------------------------- KEY MESSAGE 2: Little to no rainfall forecast through Saturday, October 10th

Increasingly moist low-level southeasterly flow will bring thickening/low clouds and a few periods of very light rain/drizzle to areas along and east of the Allegheny Front and south of Interstate 80 today into this evening.

Total rainfall is expected to be just a few to several hundredths of an inch in most places that see rain today, with an outside shot at up to 0.10 of an inch across portions of the Lower Susq Valley, NE along the I-81 corridor (across the higher terrain of Schuylkill County where llvl upslope flow will be maximized). This will be the only precip for the next 7 days.

A secondary cold front followed by colder WNW flow could bring a couple of showers downwind of Lake Erie tonight into early Monday as lake/850 mb delta Ts will be 18-19 deg C.

A subtle subsidence inversion based at 7-9 KFT AGL Monday and more notable inversion based at 5-6 kft agl Monday night, relatively short fetch over Lake Erie and the lack of very cold air aloft with cloud top temps of 0 to -5C will lead Lake- Induced CAPE of up to 500 J/KG Monday and 300-400 J/KG Monday night/Tue Morning. This will bring some thin/meandering bands of SHRA that will extend into our NW zones at times.

Otherwise, we continue to have high confidence in a prolonged dry stretch through next week as a large area of Canadian high pressure dominates the pattern.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Southwesterly flow will continue streaming in today's moisture which will provide for restrictions to develop as the morning progresses. This will mostly come in the form of low cloud decks overspreading the region leading to mostly MVFR restrictions. Have toned back some of the IFR mentions in this mornings set of TAFs but kept it prevailing to some degree at AOO and IPT. This airmass may provide some IFR continuing at JST anf coming into UNV so may need to watch those sites for future mentions later this morning/this afternoon.

Restrictions are likely to remain throughout Sunday with southern terminals most likely to see drizzly/misty conditions that may lower surface visibility. Removed -SHRA at JST and AOO with latest thinking trending towards drizzly conditions rather than full on showers. This is due to a weaker upper level forcing mechanism and unimpressive PWATs should preclude a heavier rain threat. Low clouds with widespread MVFR/IFR restrictions are likely until a cold front passes through late Sunday night/early Monday morning with drier air filtering behind it.

Outlook...

Mon-Thu. VFR prevailing. Brief restrictions possible in late night and early morning fog.

CTP WATCHES/WARNINGS/ADVISORIES

None.