Aviation Forecasts and Information Page - NWS State College PA

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Winds have shifted northerly in the wake of yesterday's weak 
frontal passage, allowing for drier air to filter in across the
Commonwealth. A subsidence inversion at around 1500 ft is 
contributing to periods of MVFR ceilings across the Allegheny 
Plateau and Laurels (KBFD/KJST/KAOO) as low-level moisture
remains trapped beneath the inversion. While the central 
mountain terminals (KUNV/KIPT) are favored to remain VFR through
Thursday evening, intermittent MVFR ceilings will be possible 
(20-30% chance) into the morning hours on the periphery of 
greater low-level moisture to the north and west. Farther 
southeast (KMDT/KLNS), restrictions are less likely through 
Thursday evening due to lower relative humidity values at the 
inversion height (RH to around 80% vs. 90-100% farther 
northwest).

As the weak front slides southward across the Mid-Atlantic, 
southerly return flow will build out ahead of a more potent low
pressure system approaching the southern Great Lakes, allowing
for the boundary to lift northward as a warm front this 
afternoon and evening. Winds of 5 to 10 kts will veer throughout
today, shifting from N-NW in the morning to S-SE in the 
afternoon. Scattered showers and lowering ceilings will 
accompany the warm front later today, with IFR ceilings likely 
(50-70% chance) to overspread central Pennsylvania from west to 
east between 00-06Z Friday as warm air advection drives moisture
back in across the region. 

Moreover, nocturnal LLWS is likely (50-70% chance) over the 
western airfields (KBFD/KJST) Thursday night as an LLJ ahead of
the system brings southwesterly winds at 925 mb to 35-40 kts. 
LLWS is less likely with points eastward, farther from the low 
pressure center moving over the southern Great Lakes.

Outlook...

Fri...Higher chances of SHRA with isolated TSRA. Restrictions
increasingly likely. Gusty S-SW winds likely ahead of front,
with gusty NW winds behind front.

Sat...Lingering SHRA across N/W PA with some -SHSN mixing in
early Saturday morning. Restrictions likely at airfields that
mix over to SHSN. Precipitation tapers off by sunrise, VFR
prevails with gusty winds. 

Sun-Mon...AM fog possible; otherwise, VFR conditions prevail.

&&