Area Forecast Discussion
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FXUS61 KPBZ 241212
Area Forecast Discussion
National Weather Service Pittsburgh PA
812 AM EDT Wed Aug 24 2016
A couple of crossing disturbances will return rain chances to the
Upper Ohio Valley Region for late Wednesday and Thursday.
.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --Convective debris from the west continues to encroach upon the
western half of the area this morning. Likewise, surface flow
looks to start to edge around from the south. This will allow for
an increase in humidity today as well as a decent uptick in
temperatures. Under a decent mixing profile at still strong, yet
filtered, sun through the convective debris cirrus, highs should
just back above normal this afternoon. Fries
An eastward shifting Plains-to-Great Lakes shortwave will ensure
increase in rain chance by tonight. That system is progged to be
the first in a series which will traverse the northern flank of
the persistent Southeast CONUS ridge, and maintain periodic precip
chances through Thursday. Improved mid level flow and resulting
deep layer shear are forecast to support possible severe storms
late on Thursday, especially over northern zones where the
southward sagging frontal boundary may spawn more numerous
convection, but that parameter is likely to be offset by marginal
instability limited by very warm mid level temperature.
With little change in pattern as the disturbances will lack ridge
erosion power, expect above average temperatures with the more
humid near term weather, forecast of which was constructed using
consensus short and superblend guidance.
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.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
Precipitation chances are projected to wane on Friday as surface
high pressure builds in the wake of a weak front. Given the
strength of the upper ridge, southward frontal penetration is
questionable, but will generally persist with a dry forecast
through Saturday as per the latest deterministic trends. Warm
weather will continue as zonal flow across the northern ridge
periphery shunts warm air across the region.
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
Little change in pattern is indicated into early next week with
the southern U.S. upper high maintaining grip. Another shortwave
is progged across the Upper Ohio during the Sunday night/Monday
time frame; hence, POPs were maintained for that eventuality as
per the latest Superblend guidance.
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions through most, if not all, of the forecast period.
An approaching shortwave is expected to result in an increase in
mid-clouds this afternoon. Any showers should hold off until late
tonight and showers may end up being non-restrictive.
.OUTLOOK /THURSDAY THROUGH SUNDAY/...
Periodic restriction chances should persist through Friday with
the approach and passage of a cold front.