Aviation Forecasts and Information Page - NWS State College PA

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
A weak shortwave moving northeastward across the Great Lakes 
will continue to bring scattered showers and thundershowers over
the Commonwealth through Wednesday afternoon. Although VFR will
prevail, brief MVFR/IFR visibility restrictions are possible in
the heaviest showers (for example, 04:37Z observation at KBFD 
showed 2 1/2 SM visibility in SHRA). Modest CAPE within the 
mixed-phase zone (~50 J/kg of CAPE between -10C and -30C) will 
support occasional lightning in the strongest cells, with 
mentions to be handled by TEMPOs wherever confidence in 
lightning is higher.

Shower activity will generally wane between 14Z-18Z Wednesday, 
with a SCT-BKN VFR cumulus deck in place during the afternoon. 
A few diurnally driven showers/thundershowers may develop 
(PROB30) between 17Z-21Z over the eastern terminals 
(KIPT/KMDT/KLNS) as the shortwave continues exiting the region,
though most areas will remain dry. Otherwise, southwest winds 
will increase to around 10 kts, with gusts of 15 to 20 kts 
likely during the day.

High clouds will filter overhead Wednesday evening ahead of a 
potent low pressure system moving across the Great Lakes. A 
band of -SHRA/-RA will overspread much of the Commonwealth from 
west to east overnight, followed by the passage of a decaying 
MCS. While the MCS will be weakening as it encounters more 
stable air across central Pennsylvania, it will be coincident 
with an unseasonably strong nocturnal LLJ (~65 kts at 850 mb, 
above the 99th percentile for this time of year). As such, a 
period of LLWS concerns + southerly ridgetop wind gusts are 
likely overnight, along with the potential for gusty winds to be
transported within the weakening MCS. 

Outlook...

Wed...Higher chances for -SHRA/-TSRA, restrictions more likely
late. High probability (90+ percent) for LLWS Wed night into 
Thursday morning as the axis of an anomalously strong 
south/southwesterly LLJ slides east across the Commonwealth. 

Thu...Restrictions possible in -SHRA/-TSRA.

Fri...Showers ending.

Sat-Sun...Chance of afternoon showers and thunderstorms over the
north and west.

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