048
FXUS61 KPBZ 171842
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
242 PM EDT Wed Jul 17 2024

.SYNOPSIS...
Showers and thunderstorms will continue through the evening with
a crossing front. High pressure will return dry conditions and
seasonable temperatures the remainder of the week and into the
weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Showers and storms expected along and ahead of a cold front
  crossing over the course of the day.

- There is a conditional risk of severe storms with the primary
  threat being wind as well as a localized flood threat.

 __________________________________________________________________


Shower and thunderstorm coverage continues with the slow
progression of the cold front this afternoon. Overall,
convection has remained disorganized with echo tops not making
it beyond 30kft. Still there is approx 1500j/kg of surface
instability and 30kts of shear so some storms may be able to
keep themselves together long enough to generate a few
strong/severe wind gusts. This is supported by SPCs marginal
risk across the region. Probably more notable is the high PWAT
values over the region in moist southerly flow and the rather
slow progression of the cold front (at least until the upper
trough pivots closer to the lower Great Lakes). This could lend
to a localized flood threat with training storms with high
rainfall rates. Have highlighted this in the HWO through the
evening hours.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
KEY MESSAGES:

- Dry and cool conditions Thursday with temperatures moderating
  to near normal Friday.

  _________________________________________________________________

Once the front passes tonight, more dry and seasonable
conditions are expected as surface high pressure builds eastward
over the region. Low- level cold and dry advection will keep
temperatures near or even a few degrees below average Thursday
and Thursday night with valley fog chances.

Stout mixing into the day on Friday under high pressure will
result in temperatures near normal, and fairly low humidity.
This will leave the area feeling comfortable for the last day of
the work-week.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
KEY MESSAGES:

- Mainly dry weekend with high pressure in control.

- Precipitation chances return for the start of the week.
-------------------------------------------------------------------

Digging trough over the central Plains may lead to a slight
increase in 500mb heights Saturday/Sunday. This may also bring
some moisture return to the upper Ohio Valley but at this time,
precipitation looks to be limited to the ridges south and east
of PGH. With rising heights, temperatures will trend higher to
slightly above normal. Strengthening southwesterly flow will
return precipitation chances into early next week ahead of
approaching low pressure.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Scattered showers and thunderstorms are ongoing this afternoon
ahead of a cold front which is slowly creeping southeastward
through the area. A mix of VFR/MVFR cu should slowly lift to
more widespread VFR by late afternoon with additional heating
and mixing occurring, though locally lower cigs/vis can still be
expected in and around the heavier showers and storms. The weak
front pushes through by roughly 03Z, followed likely by a
stratocu deck with VFR cigs except along the higher terrain east
and southeast of LBE/MGW where low cigs/vis may linger through
Thursday morning under weak upslope flow. VFR is expected by
Thursday afternoon as cooler and drier air moves into the area
behind the front.

Generally light southwest winds this afternoon ahead of the
front become light and variable overnight, then northwesterly on
Thursday in the wake of the cold front. So far, gusts in storms
have remained weak, around 20 knots, though these could
increase to 30-40 knots in late afternoon and evening as
additional heating and better lift along the front itself
support deeper convection.

.Outlook...
VFR is expected Thursday through Sunday under building high
pressure.

&&

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

&&

$$

SYNOPSIS...34
NEAR TERM...34
SHORT TERM...34
LONG TERM...34/88
AVIATION...Cermak