Area Forecast Discussion
Issued by NWS
FXUS61 KPBZ 252251
Area Forecast Discussion
National Weather Service Pittsburgh PA
651 PM EDT Thu Aug 25 2016
Showers and thunderstorms will move through the area this evening
and tonight with very warm conditions continuing through the
.NEAR TERM /THROUGH FRIDAY/...
An eastward moving short wave trough moving across the eastern
Great Lakes with best mid and upper level support well north of
the region. Scattered thunderstorms have developed along a weak
boundary/lake breeze across eastern Ohio into northwest PA. With
plenty of low level instability these storms will continue to
expand a bit and sink southeast through the evening, but coverage
may not be as widespread as previously expected. With elevated dew
points a warm and muggy night in store with well above average
temperatures. Otherwise adjusted hourly temperatures and sky
cover based on latest observations.
Shortwave will be well east for Friday with quite warm and humid
conditions as high pressure builds across the region.
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
Upper ridge of high pressure centered over the Mid-Atlantic will
continue to build through the weekend. This, and a broad area of
surface high pressure drifting across our north will keep our
area dry through a majority of the weekend with a warming trend.
Dewpoint temperatures will drop back down to around 60 by Friday
night, but will slowly creep back up through Saturday and into
By Sunday, the very humid air mass will return with dewpoints in
the mid to upper 60s common. This, and a draw of warmer air from
the south will combine for high heat indices that may near 100
degrees. How warm we get Sunday may largely depend on the arrival
of clouds associated with a disturbance passing well to our
north. Model guidance indicates the potential for
afternoon/evening showers and thunderstorms as a mid-level wave
tries to flatten the upper ridge. With the best forcing riding
over the ridge and staying to our north, coverage of showers may
.LONG TERM /MONDAY THROUGH THURSDAY/...
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 /00Z FRIDAY THROUGH TUESDAY/...
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.