668
FXUS61 KPBZ 171345
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
945 AM EDT Tue Sep 17 2024

.SYNOPSIS...
Slow moving low pressure will return limited rain chances to the
area today into Thursday, mainly for areas southeast of
Pittsburgh. Any rainfall amounts will be light. Dry weather
returns late in the week through the weekend.

&&

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

- Limited rain chances today south of Pittsburgh
-------------------------------------------------------------------

Made some generally minor tweaks to the forecast parameters
based on current conditions, but the overall forecast scenario
remains on track. Vertically-stacked low pressure will continue
to rotate in the vicinity of the Carolinas today. Moisture and
lobes of vorticity, supporting modest lift, will lift across the
Mason-Dixon Line, reaching potentially as far north as I-70
today. This will bring a chance of very light rain showers to
these areas today, with the rest of the forecast area just
seeing increased cloud cover.

While any rain will be welcome, the continued presence of a dry
column (particularly between 800mb and 500mb on the 12Z PBZ
sounding), as well as easterly downslope flow, will limit
rainfall coverage today. East-facing slopes have a better shot
of getting a little more rain, as the flow will be upslope
there. High temperatures are expected to be around 5 degrees
above average.

&&

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

- Periodic low rain chances continue into Thursday
- Seasonable temperatures Wednesday, returning to above average
  readings by Thursday
-------------------------------------------------------------------

The coastal low is progged to drift toward the Mid Atlantic
region by Thursday. Moisture and vorticity advection will
continue to rotate around the low, with some northward push
further across the region later tonight and Wednesday. This
should result in limited rain chances reaching eastern Ohio and
western PA.

Rain chances will shift further southward again on Thursday as
the low opens into a trough and reaches the East Coast. Rainfall
amounts are expected to remain minimal for most of the area,
though the eastern facing slopes of eastern Tucker county has
the best chance at seeing a half an inch or more of rain.
Elsewhere, probabilities of even a tenth of an inch of rain are
generally less than 50 percent, with the greatest chances south
of I-68.

Cloud cover and rain chances should limit high temperatures on
Wednesday, with readings near seasonable levels. Temperatures
should warm Thursday as the low moves eastward and cloud cover
decreases.

&&

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

- Dry weather through early next week
- Above average temperatures through early next week
-------------------------------------------------------------------


A cirrus shield will remain in place across the rest of the
area today, with some lowering and thickening of the cloud cover
expected as additional moisture streams in.
Model ensembles indicate a ridge will build from the from the TX
Gulf Coast, through the Upper Ohio Valley region, and into
eastern Canada Friday, and persist through the weekend.

The ridge is progged to begin to break down and shift eastward
early next week, as a trough tracks across the Midwest. The
ridge should maintain dry weather and warmer than average
temperatures through the long term period. Ensembles indicate a
more zonal flow could develop after the end of the long term
period, with at least some chance for rain towards mid week.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
VFR is expected through the TAF period as mid and high clouds
increase ahead of a low pressure system slowly approaching from
the south. A few stratocu clouds are also possible with some
limited increase in moisture at around 5kft, primarily near and
south of PIT. With the Upper Ohio Valley region on the northern
side of the low, expect a persistent east wind at 5-10kt.

.Outlook...
Occasional restrictions and showers are possible, especially
near MGW, through Thursday as the low slowly tracks across the
Lower Ohio Valley and Appalachians region. VFR is then expected
through Saturday as high pressure builds in.

&&

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

&&

$$

SYNOPSIS...WM
NEAR TERM...CL
SHORT TERM...WM
LONG TERM...WM
AVIATION...Cermak/WM