.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR is likely to prevail through 00Z Saturday with flight
restrictions limited to SHRA across Central PA tomorrow morning
& afternoon.
Clouds will increase between 02Z-07Z Friday as a shortwave
approaches from the northwest, with conditions remaining dry
through the night. An initial round of scattered showers is
expected between 12Z-17Z Friday along a narrow NNW/SSE boundary
over Central PA (closest to KBFD/KIPT/KUNV), where milder/moist
air from the southwest meets & rises over cooler/drier air from
the northeast. Most of these showers will move across the drier
side of this boundary, with VFR favored for these showers given
low-level dry air (T/Td spreads around 10 degrees C).
A second round of scattered showers will develop across this
boundary in the afternoon (18Z-24Z), driven by instability
developing on the mild/moist side (HREF mean SBCAPE around 500
J/kg). Visibility restrictions will be more likely with these
showers given the diurnally driven instability in place, with
brief gusty winds also possible given the inverted-V profile in
place (primarily KJST/KAOO/KUNV). For our other sites, spottier
shower coverage is expected due to greater distance from the
frontal boundary & less moisture being available on the drier
side, though visibility restrictions to 5-6SM are possible.
Moreover, a few thundershowers may develop given the
instability, though the low-topped nature of these showers (HRRR
modeled cloud top temperatures warmer than
-30 degrees C) precludes TSRA mentions at this time.
Outlook...
Sat-Sun..Periods of rain with MVFR to IFR conditions.
Mon...VFR likely.
Tue...VFR early, with restrictions west to east as ceilings
lower and showers move in.
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