482
FXUS61 KPBZ 190711
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
311 AM EDT Fri Jul 19 2024

.SYNOPSIS...
Dry weather will continue through the weekend for much of the
area under high pressure. The main exception will be Saturday,
where scattered showers and thunderstorms are expected mainly
south and east of Pittsburgh with a crossing wave of low
pressure. Periodic shower and thunderstorm chances are expected
next week.

&&

.NEAR TERM /THROUGH TODAY/...
KEY MESSAGES:

- Mainly dry and less humid today

__________________________________________________________________

Patchy fog is expected this morning, mainly north of PIT, and
mainly in the river valleys. Otherwise, dry weather is expected
for most of the area today as surface high pressure builds
across the Upper Ohio Valley region. An upper trough will exit
the region this morning, with rising 1000mb-500mb heights
through the day. This should result in high temperatures a
couple of degrees warmer than yesterday, but still near
seasonable levels. Dew points will remain in the 50s today,
resulting in comfortable humidity levels.

A late afternoon shower is possible across the higher terrain
area of Tucker county WV with diurnal instability, though this
potential is low.


&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
KEY MESSAGES:

- Dry weather for much of the area through Sunday night

- Scattered showers and thunderstorms possible Saturday mainly
  south and east of Pittsburgh with a wave of low pressure

_________________________________________________________________

Dry weather is expected tonight as surface high pressure builds
further across the Upper Ohio Valley region. A shortwave /
vorticity maximum embedded in southwest flow aloft is expected
to track northeastward across the lower Ohio Valley to the Mid
Atlantic region on Saturday. This could spark scattered showers
and thunderstorms for areas south and east of Pittsburgh.
Instability is expected to remain minimal, with general rainfall
amounts a quarter of an inch or less where these showers occur.
Elsewhere, dry weather will continue under surface high
pressure.

The shortwave will quickly exit the region Saturday evening,
with dry weather areawide under high pressure. The high will
then maintain dry weather through Sunday night.

Temperatures should begin to increase a couple of degrees
Saturday, outside of any precip, with warm advection under
southwest flow. This trend will continue Sunday, with rising
1000mb-500mb heights.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
KEY MESSAGES:

- Periodic shower and thunderstorm chances increase through the
  week

- Above average temperatures expected
  ________________________________________________________________

Model ensembles indicate a trough will deepen across the Central
CONUS early next week, before drifting eastward by mid to late
week. This trough should approach the Upper Ohio Valley region
by Thursday. Southwest flow ahead of this persistent trough
will result in warm, moist advection across the region.

A series of shortwaves embedded in the southwest flow, and
diurnal instability, will lead to periodic shower and
thunderstorm chances across the area. At this time, it appears
the more significant shortwave passages will be Wednesday and
Thursday, where highest POPs are focused in the forecast.
Uncertainty still exists though in the exact timing and coverage
of the rain.

Above average temperatures are expected through the period, with
increased humidity levels as well.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Probabilities are elevated that river valley fog is expected to
form in the vicinity of FKL/DUJ with radiational cooling.
GOES-16 Nighttime Microphysics imagery depicts some fog
formation as of 0530Z just north of FKL/DUJ that will likely
overspread further south over the next 2 to 3 hours.

For areas south of BVI, high resolution guidance indicates
isolated pockets of fog. Therefore, have reduced the threat of
fog in the 06Z update and adjusted TEMPOS.

Fog will quickly burn off after sunrise with scattered cu
developing by late morning.

.Outlook...
VFR conditions are expected through the weekend as a ridge axis
builds over the Great Lakes.

&&

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

&&

$$

SYNOPSIS...WM
NEAR TERM...WM
SHORT TERM...WM
LONG TERM...WM
AVIATION...Hefferan/22