Area Forecast Discussion
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FXUS61 KPBZ 201448
Area Forecast Discussion
National Weather Service Pittsburgh PA
1048 AM EDT Thu Oct 20 2016
Low pressure and a crossing cold front will generate more rain
later today and into Friday. Much cooler weather will follow for
.NEAR TERM /THROUGH TONIGHT/...
A warm front should continue to lift north across the region today
as developing low pressure tracks across the Ohio Valley. Shower
and thunderstorm chances should increase through the day with
increasing shortwave support as a deepening upper trough advances
out of the Midwest. Increasing shear should result in a severe
thunderstorm potential late this afternoon and evening. The main
threat expected is damaging winds, though an isolated tornado is
also possible. The amount of available instability is expected to
be the main limiting factor. With sufficient moisture, ascent,
and training, heavy rainfall could also result in localized
flooding. Maintained a mention of all of this in the HWO.
Instability should wane tonight, though widespread showers should
continue as the surface low crosses the area. Temperatures should
continue to average 10 to 20 degrees above the seasonal levels.
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
Showers are expected to continue Friday as the surface low and
it`s associated cold front slowly moves east of the area. The
upper trough is progged to continue it`s slow approach Friday,
with the axis crossing Friday evening.
Cold advection in northwest flow, and the proximaty of the upper
low/trough should keep shower chances continuing Saturday for
portions of the area. A few locations in the higher terrain could
see a few snow showers mix in at times. Building high pressure and
lowering inversion heights should result in rapidly decreasing
POPs by Saturday evening. Much cooler temperatures are expected,
with readings near or several degrees below the seasonal averages.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Dry, but seasonably cool conditions will return Sunday as warmer
air slowly works back into the area. Ensemble solutions continue
to push a weak front through the area sometime on Monday, which
may provide another risk for scattered showers. High pressure
builds in for the remainder of the long term.
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
General VFR can be expected into the afternoon with exception for
ZZV where encroaching stratus with a sfc trough looks to be
problematic. Conditions will deteriorate at other terminals from
the south late this afternoon and into the evening as showers and
thunderstorms develop with approaching low pressure. Expect
eventual IFR to persist through Friday morning as rainfall gives
wary to stratus in the wake of that exiting systems cold front.
.OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
Periodic restrictions are expected into Sunday as an upper trough
crosses the area.