999
FXUS61 KPBZ 161658
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1258 PM EDT Tue Sep 16 2025

.SYNOPSIS...
Other than a shower or two in the higher elevations through
tonight, high pressure will keep dry weather and above-normal
temperatures dominant into the upcoming weekend. Low rain
chances make a return to the forecast early next week.

&&

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

- An isolated light rain shower or two through tonight in the
  higher elevations, otherwise dry
- Continued above-normal temperatures
---------------------------------------------------------------

Low pressure continues to spin at the surface just off of the
North Carolina coast, with a closed 500mb low positioned closer
to Charlotte. Easterly flow to the north of the low continues to
spin high clouds into our region, with some diurnal cumulus also
noted. This easterly flow, a downsloping influence to the west
of the ridges, will help to keep the vast majority of the region
dry through tonight.

The Laurels and the northern West Virginia ridges, especially
east-facing slopes, still have a small chance of seeing a light
rain shower or two from this afternoon through tonight. This is
due to the being on the outer edge of deeper moisture (80-90%
chance of 1 inch or higher precipitable water per the HREF), as
well as upsloping influence. In any case, precip totals will be
quite light. Only the highest slopes of eastern Tucker County
have a better than 20 percent chance of a wetting rain (0.10" or
more). So, this rain will provide little to no help with the
developing drought conditions.

With the slight decrease in 500mb heights/850mb temperatures as
compared to yesterday, afternoon high temperatures should end up
2 or 3 degrees cooler than Monday. The clouds tonight should
keep overnight lows in the mid to upper 50s, or near to a touch
above normal.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
KEY MESSAGES:

- The lack of widespread rain continues
- Still warmer than normal
--------------------------------------------------------------

The coastal low is expected to degrade to an open wave as it
meanders northward into New England by Thursday. It would then
kick out into the Atlantic by Friday morning in response to
building mid-level ridging over the Lower Ohio Valley. A shower
or two may linger in the Laurels/WV ridges Wednesday morning,
but any minimal rain chances will end during the afternoon as
the system departs. Clouds will also pull east with time,
leading to mostly clear skies through Thursday night, save for
some scattered diurnal cumulus Thursday afternoon.

Due to the higher cloud coverage, high temperatures Wednesday
should be a bit closer to climatology east of Pittsburgh,
perhaps within a few degrees of normal, while eastern Ohio
temperatures climb to 8-10 degrees above normal once again.
There is some fog potential Thursday morning with light wind,
higher dewpoints, and model soundings showing a developing near-
surface inversion.

&&

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

- Still dry and warmer than normal through the weekend
- Minimal rain chances return early next week
- Temperatures slightly cooler but still above normal Monday and
  Tuesday
------------------------------------------------------------------

The dry pattern continues through Saturday with high confidence,
as the upper ridge axis crosses the Upper Ohio Valley. The
passage of a weak frontal boundary on Friday will do nothing to
dent the developing drought. With the continued rise in 500mb
heights, temperatures around 10 degrees above normal are still
expected.

Ensembles are continuing a trend of slowing down the approach of
the next upstream trough. Differences remain, but it appears
that the axis of the disturbance remains back over the Upper
Midwest and lower Ohio Valley during the Sunday/Monday period.
This leads to a downward trend in the already low PoPs that were
in place, with only a sub-20 percent chances mentioned north and
west of Pittsburgh through the Monday daylight hours. By
Tuesday, uncertainty in the depth and position of the shortwave
continues to grow, but clusters still show decent confidence in
only a minor eastward displacement by Tuesday, resulting in only
slightly better rain chances. For now, there remains little
potential for a much-needed widespread wetting rainfall.

This uncertainty extends to the temperature forecast a bit as
well. A faster/slightly deeper trough could lead to temperatures
closer to climatology, while the slower solutions would continue
the warmer pattern. This latter solution seems more likely given
the ongoing dryness and better ensemble support, so temperatures
between 5 and 10 degrees above normal seem reasonable for the
forecast.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
High confidence VFR continues through the TAF period as high
pressure remains across the region. Winds will remain light and
variable, though generally easterly. As expected, Scattered
afternoon Cu has developed between 7-10kft. Cu is expected to
erode this evening after sunset and leave just the high clouds
filtering in from our coastal system near SE Virginia.

More notable high cloud coverage is expected keep the lid on
fog potential overnight with cloud fractions dipping to around
40% at their lowest near FKL.


.OUTLOOK....
Surface high pressure near New England will continue to dominate the
weather pattern, promoting VFR and light easterly wind. Clear sky
nights may result in patchy river fog during the pre-dawn hours.

&&

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

&&

$$

SYNOPSIS...CL
NEAR TERM...CL
SHORT TERM...CL
LONG TERM...CL
AVIATION...AK