FXUS61 KPBZ 161756
Area Forecast Discussion
National Weather Service Pittsburgh PA
156 PM EDT Thu Aug 16 2018
Periodic shower and thunderstorm chances are expected today
through part of Saturday with a series of crossing disturbances.
Dry weather returns Sunday under high pressure.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Morning update was made only to make minor changes to the next
few hours as rain spreads into eastern OH. Otherwise, forecast
is currently on track.
A shortwave in SW flow ahead of the main Midwestern trough is
progged to approach the region today, with increasing POPs for
showers and thunderstorms. Maintained likely POPs for much of
the area by afternoon when the greatest shortwave support is
progged. Existing cloud cover should limit the amount of diurnal
destabilization and the resultant severe weather potential.
PWATs increase, though a sufficient storm motion should preclude
anything more than an isolated flood potential. Highs should be
near seasonal levels.
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
Maintained likely POPs tonight as the shortwave completes its
passage, and low level jet support increases. Sufficient storm
motion should again limit any localized flood potential to areas
that see training. Included a slight chance of thunder through
the night with the low level jet and minimal elevated
Additional shortwaves in SW flow ahead of the main trough should
support periodic shower and thunderstorm chances through
Friday. Shear is progged to increase some, though cloud cover
should limit instability. A few strong storms are possible if
enough partial clearing and greater destabilization occurs.
Shower and thunderstorm chances are expected to continue Friday
night through part of Saturday as the main upper trough, and
its associated cold front, cross the region. Tapered POPs down
from N-S Sat as the front sinks S. Expect mainly dry conditions
area wide by late Saturday night as the front exits.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Ridging should return dry weather for Sunday and most of Monday.
A trough is progged to advance out of the Plains and
approach/cross our region Tuesday through part of Wednesday.
Maintained likely POPs Tue as the trough and its associated sfc
low/cold front tracks across the region. Slight to low chance
POPs were included for Wednesday until the trough exits E. Near
to above average temperatures should fall to below average
readings by midweek.
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Little change to the 18z set of TAFs as moisture increasing from
the southwest and a supporting shortwave allow for expanding
shower coverage through the afternoon. Instability will be
rather meager west of I-79 but still thought it best to keep a
VCTS mention based on the latest radar and mesoanalysis trends.
VFR should generally prevail, though some visibility
restrictions where heavier showers and storms pass over a
terminal given the saturated atmosphere.
Models continue to suggest some degradation in ceilings
overnight, which seems reasonable given upstream conditions.
Thus, will carry MVFR cigs toward morning for most sites, with
greatest confidence north and west of PIT. Fog should be limited
as a result of continued mixing overnight.
Coverage of showers should decrease toward morning, leading to
a return to high VFR/high MVFR conditions before the next
shortwave approaches later tomorrow.
Brief restrictions are possible until a cold front passage
Saturday. VFR conditions expected later Saturday and Sunday.
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