352
FXUS61 KPBZ 300345
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1145 PM EDT Fri Aug 29 2025

.SYNOPSIS...
High pressure will provide mostly dry conditions through the
Labor Day weekend, with a slow moderation in temperature back
towards seasonal levels by early next week. The next decent
chance of rain arrives Wednesday into Thursday with an
approaching front.

&&

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

- Dry weather and below average temperature through tonight
- Potential for locally dense valley fog overnight
---------------------------------------------------------------

The prior forecast remains on track. Locally dense fog is
possible tonight, with guidance continually hitting on river
valleys.

.. Previous Discussion ..

Clouds will continue to decrease this evening as surface high
pressure tracks southeastward across Michigan. The clearing sky and
decreasing wind will promote radiational cooling. Widespread lows in
the 40s are expected, with some upper 30s possible in sheltered
valleys/normal cold spots. Would not be shocked if the Canaan Valley
NWR mesonet site manages to drop into the 20s. With the rivers
remaining warm, a round of valley/river steam fog appears
likely. HREF visibility probabilities target areas north of
Pittsburgh as having the best potential for locally dense fog
(perhaps under 0.5 mile visibility in spots).

&&

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

- Valley fog forecast each morning, with a slight warming trend
  in temperatures with dry conditions for most.
----------------------------------------------------------------

Another night of mostly clear skies will lend to efficient
radiative cooling Saturday night as area lows dip into mostly
the 40s. Because of thermal contrast between area rivers and
the air, vally fog will be likely yet again, locally dense at
times but confined in spatial area. Typical sheltered valley and
higher elevations in the I-80 corridor and eastern Tucker may
see some locally cooler spots. High clouds may increase late.

A shortwave trough axis is expected to pass Sunday on the
backside of a departing height min over the Canadian Maritimes.
WInds aloft will reorient more northerly in its wake, though
piratical impacts will be minimal. Height rises in its wake may
result in surface temperatures a bit closer to normal, with a
fair weather cumulus deck. Slightly cooler low levels and warmer
surface temperature may result in a slightly higher, but still
low chance of rain in eastern Tucker County WV.

ANother mostly clear forecast is expected Sunday night with
Valley fog possible, through temperatures may be a few ticks
warmer than the preceding nights with an increase, but still
low amount, of low-level moisture.

&&

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

- Dry, quiet, and seasonable Labor Day.
- The next rain chances appear Wednesday and Thursday, with a
  cold frontal passage likely on Thursday.
-------------------------------------------------------------------

A broad pattern of upper troughing will persist for much of
next week, with a general pattern of surface high pressure and
dry mid-to-upper levels. This should keep the area mostly dry,
with temperatures only getting up to around seasonal normals
Monday and Tuesday, with lows a few ticks below normal in
radiative cooling and daily chances of morning vally fog under
mostly clear skies.

Rain chances finally increase again Wednesday and Thursday with
the approach of the next front. A bit of temperatures and
precipitation uncertainty exists on Wednesday and pre-frontal
southwest flow may advect moisture in along a weak Appalachian
trough. In the event the area does see deeper saturation,
temperatures may be a bit below normal during the day, while in
the event moisture struggles to get into the area, more
seasonable and drier conditions are more likely. More moisture,
of course, would mean a cloudier solution as well.

The cold front itself and affiliated rain (and perhaps thunder)
are fairly confident to pass sometime Thursday and the exact
timing may affect daytime highs. An earlier passage would mean
cooler conditions, while a later passage would mean warmer
temperatures. NBM 25th-75th percentiles sit anywhere between the
upper 60s and upper 70s. A well mixed pre/post frontal
environment with 40kts to 50kts of sfc to 500mb shear also
indicates Thursday might be a gustier day, with winds up to
20mph to 30mph.

Another seasonably cool and mostly dry weekend appears most
likely for the first full weekend in September under residual
upper troughing. CPC outlooks agree, slightly favoring cool
temperatures in the 9-10 and 8-14 day period.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Regional satellite shows a bit more robust stratus and cirrus
over the area and upstream than previously anticipated. BKN/SCT
ceilings are expected to remain near 5kft with before eventually
scattering from north to south early Saturday morning. Because
of this, have reduced fog mention. Clearing by 9-10z should be
sufficient for some river fog development, with greatest
probability at FKL and MGW.

Lingering cold advection and moisture is likely to result in a
few to scattered 3-6kft cumulus Saturday after 15z. Wind will
remain light and northerly through the period.

.OUTLOOK...
Save daily morning fog chances, VFR is confidently forecast
through the Labor Day weekend with prevailing high pressure.

&&

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

&&

$$

SYNOPSIS...CL
NEAR TERM...CL/Milcarek
SHORT TERM...Milcarek
LONG TERM...Milcarek
AVIATION...Rackley