textproduct: State College

WHAT HAS CHANGED

* No major changes to the forecast at this time. There is a low chance of isolated rain/snow showers for south-central PA, mainly during the afternoon.

KEY MESSAGES

1) Low pressure system passes by to the south this afternoon, but may bring isolated rain/snow showers just north of the PA/MD border

2) End-of-February warm-up before a system brings the next chance for light accumulating snowfall Saturday night into early Sunday

3) Keeping an eye on additional rounds of wintry weather early next week

DISCUSSION

KEY MESSAGE 1:

An upper level shortwave embedded in the flow of broad upper level trough over the eastern U.S. and a developing surface low will both be passing by to the south this afternoon and exiting the mid-Atlantic coast by early evening. While most of the moisture associated with this disturbance is expected to remain south, clouds will increase and there is a low chance (~20-30%) of rain/snow showers extending north of the PA/MD border up to about I-81/I-78 corridor, primarily between 17-22Z. While surface temperatures are expected to be in the upper 30s and low 40s in this area during the afternoon and most of the light precipitation is expected to be in the form of rain, there is enough dry air aloft that can lead to enough evaporative cooling to allow for the potential of wet snow to at least mix in during this time. Highs across Central PA today range from the low and mid 30s to the north to the upper 30s to mid 40s south.

KEY MESSAGE 2:

Surface high pressure building in and warm air advection bring an end-of-February warm-up and a taste of spring to the area Friday and Saturday. High temperatures Friday will be mainly in the upper 40s and low 50s (a bit cooler in the low-to-mid 40s in the higher terrain to the north). Highs Saturday will mainly be in the low-to-mid 50s with some areas of South Central Pa reaching the upper 50s and even making a run at 60 degrees south of the PA turnpike.

A cold front crossing the area Saturday night and early Sunday morning is expected to bring the next chance of rain and snow showers to Central PA and with a cold, Canadian high pressure area dropping in from the NW out of central Canada, colder air will be making a return for the second half of the weekend and early next week. Sunday features a wide range in temperatures with highs from the 20s to the north to the low 40s over South Central PA. Monday's highs are expected to be in the 20s and low 30s.

KEY MESSAGE 3:

A couple of disturbances will be monitored heading into early next week. Deterministic and ensemble model guidance show a system from the Midwest moving into the mid-Atlantic region Monday. With the fresh injection of cold air in place, this would lead to the next chance of widespread snowfall, especially from around I-80 on south. Additional chance of rain and snow showers continue Tuesday into Wednesday but the cold air will be gradually retreating during this time.

AVIATION /07Z THURSDAY THROUGH MONDAY/

KBFD is expected to bound between VFR and MVFR ceilings through 12Z-14Z with light west to west-northwest flow persisting and tapping into just enough moisture off of Lake Erie. As winds become calm and the flow aloft slightly more west-southwest, the ceiling restrictions are expected to lift for the rest of the TAF period.

The remaining terminals are expected to be VFR through the 06Z TAF forecast with clear skies in place early followed by increasing clouds as a surface low passes by to the south this afternoon and evening. While there is a slight chance of a rain shower or a few flurries around KLNS and KMDT from 17Z-22Z, restrictions are not expected.

Outlook...

Thur. Night...VFR conditions expected.

Fri-Sat...Dry conditions with VFR probable. Rain and snow showers and associated restrictions possible Sat. Night into early Sun.

Sun...Mainly VFR

Monday...Snow showers possible and associated restrictions. Confidence is low but KJST, KAOO, KMDT and KLNS look to have the best chance at this time.

CTP WATCHES/WARNINGS/ADVISORIES

None.