409
FXUS61 KPBZ 311718
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
118 PM EDT Sun Aug 31 2025

.SYNOPSIS...
Seasonable and mostly dry conditions prevail through Tuesday.
Rain chances return Wednesday and Thursday with the approach and
passage of a cold front. The front passage is most likely
Thursday afternoon with gusts of 30mph to 40mph possible. Cooler
and relatively drier weather returns late-week.

&&

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

- More seasonable and dry.
- Low chance of rain in Tucker County, WV.
- Valley fog possible in the morning.
---------------------------------------------------------------

With 850mb temperatures slightly warmer than the day prior, highs
are expected in the mid to upper 70s for most (near to slightly
below normal). Once again, some shallow moisture may allow for an
afternoon fair weather cumulus deck.

Models continue to hint on the low chance of a shower or sprinkle in
the West Virginia mountains. Lower levels show the high beginning to
build into the region while the mid to upper-level flow still has
the edge of the trough near northern WV. This will bring some
northwesterly flow along the WV ridge-line. If the lift is combined
with 100-200 J/kg of surface CAPE (buoyancy), some showers
could develop, however, there is a low probability of them
occuring (up to 20%).

Another radiational cooling night is expected late Sunday under
mostly clear skies and only a light east-northeast wind. This will
allow another night of temperatures dropping 10 degrees below
normal. With these favorable conditions, there is the potential for
some valley fog.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
KEY MESSAGES:

- Valley fog chances each morning with seasonable temperatures.
----------------------------------------------------------------

Benign weather = high confidence forecast! No changes to the
taste of fall weather at the beginning of meteorological fall
/September - November/ for the short term. A splendid day with
wall to wall sunshine for cookouts on Labor day and to grill on
Tuesday.

Only slight warming in the column noted this week, which
supports the continued theme of a slight uptick in daytime max
temperatures. Tuesday will be the warmest day of the week with
values near 80F save for the mountains and locations north of
I80.  A light easterly wind with a weak downslope component
supports a dry airmass with dewpoints in the 40s each afternoon.

Patchy valley fog will occur each morning given the delta T
between land and area rivers. This is mainly in the headwaters
of the Allegheny River.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
KEY MESSAGES:
- A drink for moisture starved lawns Wednesday and Thursday.
- Cold front will drop temperatures Friday into the weekend
  accompanied by gusty winds.
-------------------------------------------------------------------

Little change to the extended forecast as the main weather
system is poised to move through at the beginning of the forecast.
High confidence exists with a wetting rain
areawide as a front moves through Thursday.  There will be slight
timing shifts as we get closer, but pops continue to be increased
into the categorical range.

Cluster analysis largely made up of the GEFS and ENS continue to
advertise a cut off low at H5 days 4-6 dropping south from the
Great Lakes. The main differences center around the strength of the
cyclone as timing differences seem to be better resolved than this
time yesterday. The next period of uncertainty is at the end of
next weekend and how fast the low lifts?  Even though this won`t
have an impact on pops since dry weather is forecast.  It could have
an impact on temperatures as the GEPS and ENS clusters build heights
back toward 580dm /a quicker return to normal or above normal
values/ while GEFS heavy clusters keep heights about 10dm lower /a
slower return to normal numbers/.

The baroclinic zone is projected to cross during the day Thursday.
This will bring needed rainfall to the abnormally dry conditions
that have been documented in the latest drought outlook.  Southerly
wind brings increased moisture into the column.  PWATS climb from
less than an inch Tuesday morning to ~1.4" ahead of the front.  Mean
QPF values Thursday are around 0.50".  There is a 75% chance of a
wetting rain />0.10"/ with a 10% chance of an inch or more.  Given
the start of the summer and how wet it was, hard to think we would
be wanting the 90th percentile forecast to verify!

With fropa during peak heating, there is a low chance
for severe thunderstorms.  Machine learning output from Colorado
State and NCAR highlight a 5-15% for severe weather.  Still too
early to include in any messaging given timing and instability
confidence.

The coolest day of the entire seven day forecast is Friday.  If
temperatures stay in the 60s, we could be looking at potential
record low maximums.  As of now, to attain upper 60s, it would be
only a 10-25% chance of occurrence given the QMD stats from the NBM.
The mean /current forecast/ has daytime highs climbing into the 70s
save for I80 in PA and north of US 30 in eastern Ohio where values
range from 67F-69F.

It is setting up to be another fantastic weekend with sunshine and
temperatures in the upper 60s to mid 70s with a moderating trend
each day.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
VFR conditions will persist into the overnight hours. Few fair
weather cumulus possible this afternoon with winds light out of the
northeast.

Overnight, winds will remain light and become more easterly.
Although skies remain relatively clear, the wind doesn`t become
completely calm. This could inhibit any river valley fog
development.

.OUTLOOK...
Restrictions will return Wednesday and persist through Friday
morning. Wednesday`s precipitation is associated with an upper-level
shortwave trough with rain mainly staying south of Pittsburgh and
could bring some MVFR conditions.

Thursday, the passage of a cold front will bring rain with the
possibility of isolated thunderstorms. The boundary is also forecast
to bring a strong vertical wind profile, which increases the
chance for low-level wind shear and/or wind gusts.

&&

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

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...Milcarek/Lupo
SHORT TERM...McMullen
LONG TERM...McMullen
AVIATION...Lupo