textproduct: State College

WHAT HAS CHANGED

* Refined PoPs for Sunday * Mid-week warmth may be tempered across the N

KEY MESSAGES

1) Sunday precipitation should stay S of I-80 if not south of the PA Turnpike

2) Thaw next week also has high chance for rain, especially across the north.

DISCUSSION

KEY MESSAGE 1: Sunday precipitation should stay S of I-80 if not south of the PA Turnpike

Low pressure develops tonight over TX/OK as has been advertised for quite some time. Current projections from almost all models has the center of the storm tracking pretty much straight to the east. It should throw precip far to the north, though. Current QPF forecasts don't even make 0.1" along the MD border. But, most models do sneak a little light precip into the state. PoPs of >20pct get up to JST-AOO-MDT. Slight chc PoPs remain as far N as I-80. Temps will be marginal for any of it to reach the ground as snow before sunset as the best timing is for precip to start mid-day Sunday, and end by midnight. If any of this light precip continues past sunset, it may turn to snow. So, we may get the thinnest of coatings, mainly on the grass/mulch, since temps are progged to get up to 40-45F before the clouds thicken up and lower on Sunday. The wind will be light and variable.

---------------------------------- KEY MESSAGE 2: Thaw next week also has high chance for rain, especially across the north.

Temps start their climb Saturday, and maxes get near 50F along the MD border. As high pressure slides east of PA on Tuesday, the warmer air will get into nrn PA. Then, a slightly cooler airmass tries to slide in from the N, creating a baroclinic zone ripe for low pressure areas to move along it and in from the west. The clouds and likely precip (rain) from the first wave will temper the warm up on Wed & Thurs over at least the nrn tier. There is a small chc that the a little snow could mix in over the higher hills of the north. The colder air should work into srn PA Thursday or Friday, but temps look like they'll still be above normal, probably more-so due to cloud cover Thursday. Another wave of low pressure approaches for next Friday.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

Skies will begin this evening relatively clear. However, high clouds are advancing on PA from the NW with the approach of a fast- moving and weak bump in the mid levels. This feature should increase and lower the clouds and make isolated light SHSNs tonight VCTY BFD. But, the main effects to aviation will occur after the sfc trough associated with the shortwave passes. Clouds will (90% chc) lower to IFR at BFD and borderline MVFR at everybody else except MDT and LNS and IPT. IPT is just about the only other spot which could see any snowflakes, but we are not expecting a reduction is vsby with any of those at IPT.

Winds should go mainly calm early tonight; however, as the disturbance moves overhead it could cause a few hours of LLWS across the western terminals. Winds will pick up slightly on Sat behind the front. Clouds should break up some for the SE half of the area on Sat aftn. BFD and JST don't lose the low clouds. On Sunday a system will roll south of PA, but spread some -SN/RA into the southern tier. IFR possible (50%) JST-MDT- LNS in -SN/RA Sun aftn & evening. MVFR expected (100%). Elsewhere, IFR cigs/visby unlikely (30%).

Outlook...

Sun...Low clouds with scattered rain/snow mix over the area.

Mon...Low clouds linger much of the day. IFR expected NW.

Tue...Mainly VFR.

Wed...IFR -RA/cigs N, MVFR -RA/cigs elsewhere.

CTP WATCHES/WARNINGS/ADVISORIES

None.