National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 260359
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1159 PM EDT Tue Jul 25 2017

.SYNOPSIS...
While showers and thunderstorms are expected Thursday and
Friday, the rest of the seven day forecast should be dry with
near normal temperatures.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Main change was to add some clouds southeast of Pittsburgh as
stratocumulus has expanded once again over the area. Hi-res
models have this largely dissipating over the next few hours and
have played the grids that way, although clouds may hug the
eastern slopes a little longer. Valley fog is still expected as
the rivers are quite warm. Reduced low temperatures slightly
given the low dewpoints.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
While widespread cloud cover is not expected tomorrow morning,
valleys are expected to have fog around sunrise. After fog
clears out, a mostly sunny day is forecast. With winds having
swung around from the north to south and less cloud cover
present, highs should warm back towards seasonal levels.

Clouds will be on the increase Wednesday night in advance of a
cold front that will slowly work its way across the region.
Primary change made with this forecast package was to spread out
precipitation over a wider period, partially because of the
surface front taking longer to cross the area and partially
because a second upper level wave will give some reinforcing
lift on Friday. While locations south and east of Pittsburgh are
in a slight risk for the Thursday convective outlook, the
uncertainty in the evolution of the system is also higher than
normal. Likely pops were kept in the forecast, with the mention
of categorical pops removed due to uncertainty in timing.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Showers could linger into Friday night and even Saturday
morning, but so far have not been too aggressive with keeping
pops in the forecast longer. Once conditions dry out, high
pressure over the Great Lakes could keep the rest of the
forecast dry, although another front may cross the Great Lakes
by the end of the forecast period. Temperatures will remain
seasonable.

&&

.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions will persist through much of the early TAF
period with high pressure in place. Expect some MVFR fog to
develop across the valleys and ports early Wednesday morning due
to a radiative cooling night. Based on latest dew point
temperatures and model soundings, not confident to include IFR
fog in TAFs as this time as some models are indicating.

Conditions should improve after sunrise where any fog does
develop, with VFR prevailing thereafter under subsidence.

.OUTLOOK...
Restriction chances return Thursday as low pressure impacts the
Ohio Valley.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...None.
OH...None.
PA...None.
WV...None.

&&

$$