009
FXUS61 KPBZ 180718
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
318 AM EDT Thu Jul 18 2024

.SYNOPSIS...
Low clouds and fog will end this morning as high pressure builds
across the region. The high will maintain dry and less humid
conditions through the weekend for much of the area. Areas south
and east of Morgantown could see scattered showers and
thunderstorms Saturday with a weak wave of low pressure to the
south.

&&

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

- Areas of stratus and fog ending

- Mainly dry and less humid weather after the passage of a cold
  front

__________________________________________________________________

A cold front extended across west central PA through northern
OH. The front has become nearly stationary with the 500mb almost
parallel to the front. The front should begin to accelerate
southeastward this morning as the 500mb flow becomes more
westerly ahead of an approaching shortwave trough.

Areas of fog and stratus continue across the region with low
level moisture in place, and additional moisture pooling in the
vicinity of the front. Increase mixing and dry advection is
expected after FROPA, which should result in a gradual
dissipation of the fog and stratus. A few showers or a
thunderstorm are possible across Preston and Tucker counties as
the front completes its passage this morning.

Otherwise, building surface high pressure will result in dry and
less humid conditions today. Expect a scattered to broken
cumulus cloud layer after the initial low clouds dissipate, as
convective temperatures are reaches, and as an upper trough
crosses the region. High temperatures will be closer to average
for this time of year than in recent days.

&&

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

- Dry through the period north of I 68 under high pressure

- Southern stream shortwave brings shower and thunderstorm
  chances south of I 68 Saturday
  _________________________________________________________________

Surface high pressure is expected to slowly build across the
Midwest and Upper Ohio Valley regions through Saturday night.
Dry weather and lower humidity levels are expected to continue
for most of the area. River valley fog is expected tonight, as
air temperatures fall into the 50s, while river water
temperatures are in the 70s and 80s. This should create steam
fog in the valleys.

Increasing mid and high clouds are expected across the region
Friday night and Saturday as a shortwave trough approaches and
tracks across the lower Ohio Valley/Mid Atlantic regions. This
wave is expected to spark scattered showers and thunderstorms
near and south of the I 68 corridor on Saturday. THe wave will
exit the East Coast Saturday night, with clearing skies and dry
weather.

Seasonable temperatures should begin to increase by Saturday
north of the I 68 corridor, where more sun is expected. Precip
could hold cooler temperatures in place south of I 68.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
KEY MESSAGES:

- Mainly dry weather to start under high pressure

- Periodic shower/thunderstorm chance return by late Monday
  through mid week
-------------------------------------------------------------------

Shortwave ridging, ahead of an approaching Central CONUS trough,
will maintain dry weather through most of Monday. Increasing
1000-500mb heights and warm advection should return temperatures
to above average readings again, with increasing humidity
levels.

Model ensembles indicate the approaching trough will drift
slowly eastward through the middle of next week. Moist
advection, and individual shortwaves embedded in southwest flow
ahead of the approaching trough, should return scattered
showers and thunderstorms to the forecast late Monday through
mid week. Temperatures should average above seasonable levels
through the period.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Sufficient low-level moisture, from passing showers and storms
over the last 12 hours, has created areas of fog and low-lvl
stratus early this morning. The cold front has stalled in the
vicinity of BVI/FKL/ZZV. Adjustments have made to the TAFs for
prolong period of IFR/LIFR for a majority of most sites.

Fog/stratus will likely dissolve between 12Z to 14Z with diurnal
heating. Then, VFR is expected at all ports. VFR Cu should
develop with daytime heating, mainly between 14Z to 16Z.

.Outlook...
MVFR to IFR fog may develop for FKL/DUJ during the early morning
hours of Friday. Otherwise, VFR conditions are expected Friday
afternoon into Saturday 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