Area Forecast Discussion
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FXUS61 KPBZ 251444
Area Forecast Discussion
National Weather Service Pittsburgh PA
1044 AM EDT Thu Aug 25 2016
A couple of crossing disturbances have returned rain chances to
the Upper Ohio Valley Region for this morning, and again late
this afternoon and evening.
.NEAR TERM /THROUGH TONIGHT/...
The leading short wave trough has nearly cleared the eastern flank
of the area with abundant low level moisture remaining in its
wake. This has allowed for fairly pervasive stratus development
this morning, however diurnal turbulent mixing is starting to
break some of this up, and it is likely to continue to do so going
into the afternoon. As 850 mb temperatures surge toward 19C,
mixing depth increases, and dewpoints continue an uptick into the
70s, heat index values will thus rise toward 95-100 this
Going into the evening, shear will increase, especially over the
northwestern portions of the area with helicity values running up
toward 150 m2/s2. This will occur as the trailing section of weak
mid-level short wave edges through the norther flange of the area.
While the vast majority of large scale lift will be transiting to
our north, this may be enough to kick off a thunderstorm with a
damaging wind gust or tornado late this evening and early tonight.
This was added to the HWO. Fries
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Precipitation chances are projected to wane on Friday as surface
high pressure builds in the wake of a weak front. Have persisted
with a dry forecast through Saturday as per the latest, and
consistent deterministic trends. Warm weather will continue as
zonal flow across the northern ridge periphery shunts warm air
across the region.
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Little change in pattern is indicated through the first half of
next week with the southern U.S. upper high maintaining grip, but
with tropical system encroachment toward the Southeastern Coast. Shortwaves
with the zonal flow over the immediate area would support periodic,
and diurnally-supported precip chances for the long term. Low-confidence
slight to chance POPs were maintained for that eventuality as per
the latest Superblend guidance. Warm temperature can be expected
given the lack of any significant airmass alteration.
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Showers and a few thunderstorms will encroach from the west
during the early portions of the forecast. Expect coverage and
intensity to continue to decrease overnight, so have only included
restrictions in a tempo group. Shortwave that has sparked the activity
will clear the area quickly this morning. Expect a quick return to
vfr conditions after sunrise.
.OUTLOOK /FRIDAY THROUGH MONDAY/...
Periodic restriction chances should persist through Friday with
the approach and passage of a cold front.