textproduct: State College

WHAT HAS CHANGED

Increased pops and coverage of showers early today. The showers and isolated thunderstorms will be limited to the mid and late morning hours for much of the state.

KEY MESSAGES

1) A welcome break from the episodic precip pattern and high humidity will begin today and continue into the upcoming weekend before thunderstorm chances return Sunday.

DISCUSSION

KEY MESSAGE 1: A welcome break from the episodic precip pattern and high humidity will begin today and continue into the upcoming weekend before thunderstorm chances return Sunday.

The nose of a 110 KT upper level jet will moving southeast across Central PA early this Thursday morning with a quite strong, diffluent patter between it, and another just segment across Northern New York.

This Meso-B scale forcing has led to an expanding (but still quite focused) area of showers and a few low-topped TSRA that brought a general 1-2 tenths of rainfall in about a 15 minute period as they moved through KUNV and surrounding areas over the past 1-2 hours. This convection will impact the Lower and Middle Susq Valley through shortly after daybreak, with just a few stray/brief showers possible during the 12-15Z window - mainly across the NW Mtns of PA where a BKN-OVC stratocu layer could persist until around 15Z.

Short range ensemble guidance indicates that mid morning clouds will quickly break with a decent amount of sunshine (mixed with cirrus) developing by shortly after daybreak across the Central Ridge and Valley Region of the state.

The remnants of an area of strong to potentially severe TSRA over the Midwest later this evening will move quickly east overnight as a remnant MCV and likely link up with the right entrance region of a strong jet core stretching from Southern Ontario to the New England Coast, bringing another round of clouds (and a few to several hour period of showers - mainly in the late morning through mid afternoon across the SW 1/3 of the state.

Clearing with a light northerly breeze and comfortably lower humidity will follow for Friday night and Saturday.

Looks like the more active day may be Sunday vs. Monday, but could see the activity linger into Monday. Like recent events, warm advection and directional shear support storm formation, as the warm air moves back into the area on Sunday.

Latest trends suggest the front will have a harder time pushing south of the MD line into the weekend. We still expect a brief break in the episodic tstm precip pattern and very muggy conditions Friday night into Saturday, but the chance of rain will linger over portions of the southern tier of CPA. Ensemble data shows a ramp in precip odds for Sunday into Sunday night in advance of a frontal system pushing eastward from the Great Lakes and Ohio Valley.

AVIATION /07Z THURSDAY THROUGH MONDAY/

A small area of showers (some briefly moderate to heavy in intensity) will move SE through the KMDT and KLNS areas between 09-11Z today, bringing a tenth of an inch or so of rainfall, followed by improving conditions with gradual clearing of the bulk of low and mid-level clouds.

Early morning IFR then MVFR Strato Cu across the NW Mtns will dissipate by early this afternoon. Sunshine dimmed by variable amounts (and thickness) of high clouds will follow for this afternoon and evening.

Flight cats will improve from MVFR to VFR through late morning with widespread VFR probable by 18Z Thu.

Outlook...

Thu...Scattered showers/storms mainly across the southern Tier of PA through Thursday night.

Fri...Mainly VFR. A few afternoon showers or storms possible over southwestern PA.

Sat...AM fog possible, then mainly VFR.

Sun-Mon...Restrictions possible in showers/thunderstorms.

CTP WATCHES/WARNINGS/ADVISORIES

None.