271
FXUS61 KPBZ 031435
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
935 AM EST Mon Nov 3 2025

.SYNOPSIS...
The work week will feature near normal temperature with warm
advection surges aiding seasonably warm readings Wednesday and
Friday. Dry conditions are favored outside of isolated showers
north of interstate 80 today and areas of light rain Wednesday
evening. A weekend pattern shift portends to more frequent
precipitation chances and temperature falling below the daily
average.

&&

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

- Low probability shower/sprinkle possible.
- Warm advection prior to front offers seasonable warm
  temperature across the region

---------------------------------------------------------------

As of 9:30am, a weak trough passage is showing some returns on
radar as it crosses the area. Only a few spotty observations in
Ohio are showing rain accumulation, so much of the bulk of the
returns are likely virga showers, but a brief sprinkle could
not be rules out as it crosses the area through 1pm. No impacts
are expected.

.. Previous Discussion ..

Swift movement of an upper level shortwave across the northern
Great Lakes is expected today, pushing through a nominal surface
cold front by late this evening. Displacement of the surface
boundary plus jet ascent farther north means the region is
unlikely to see any rain outside of a few isolated lake enhanced
showers north of I-80. The front/trough axis impact will be more
tied to increased cloud cover during the late morning to
afternoon hours that will temper insolation; temperature will
remain near the daily average as this cooling effect is expected
to offset modest warm advection in southwest flow ahead of the
cold front.

Deeper mixing and tightening surface gradient is expected to
result in 20-30 mph gusts for lower elevation areas and up to 40
mph in the Laurel Highlands/WV Higher Terrain. Probabilities (no
higher than 20%) do not support wind advisory criteria gusts for
large enough forecast areas.

High pressure will rapidly fill behind the exiting
front/shortwave overnight, creating clear skies and weakening
wind. The degree of decoupling will be the primary determination
in how cold things are come Tuesday morning, but current means
favor slightly below average lows.

&&

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

- Dry and seasonable weather Tuesday.
- Warmer Wednesday prior to cold front and increased rain
  chances
----------------------------------------------------------------

Height rises aloft and surface high pressure strongly favor dry
weather and seasonable temperature Tuesday across the upper Ohio
River Valley.

Another fast-moving shortwave trough is expected to enter the
northern Great Lakes by Wednesday afternoon and deepen slightly
as it enters New England late Wednesday night. Angle and timing
of this shortwave will better allow warm advection in southwest
flow ahead of the cold front, which will push area temperature
to near 10 degrees above the daily average (closer to 5 degrees
for locations north of Pittsburgh). A drop in the trough axis
and its attendant jet will better position enough lift to
introduce precipitation chances north of I-70 and into the
higher terrain. There are subtle variances in low positioning
that would alter where showers may occur; the prior dry air mass
and system pace could cause this to be more of a NW PA and
higher terrain rain shower event while other areas remain dry.
Regardless, any precipitation that falls will be light and offer
little accumulation (less than 10% probability of greater than
0.25" for all areas).

High pressure and height rises aloft are expected to quickly
diminish any rain heading into Thursday morning. Lingering wind
from the surface gradient should limit the degree of overnight
cooling as well.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
- Widespread rain is likely Friday with next low pressure system
- Ensembles coalescing more for a shift to colder, wetter
  pattern
-------------------------------------------------------------------

There is little variance expected Thursday as broad shortwave
ridging crosses over high pressure at the surface, creating dry
and seasonable weather for the upper Ohio River Valley. The
turbulent pattern continues Friday as another, deeper upper
level trough enters the Great Lakes region. Depending on the
timing of the trough/front and its axis of rain, there could be
enough warm advection for above normal readings by early
afternoon Friday. Otherwise, the passage of the trough axis and
surface front is highly likely (60-80% probability of measurable
rain) sometime between Friday afternoon and Saturday morning
before exiting into the Atlantic.

Ensemble model spread does grow through the rest of the weekend
into next week, but the main theme in each plausible scenario is
the development of a deeper trough over the eastern CONUS amid
western U.S. ridging. This pattern favors a turn toward near to
below normal temperature with potential for more frequent bouts
of precipitation chances. Snow is thus becoming a more likely
occurrence sometime between Sunday into early next week,
favoring the higher terrain and northwest PA. That said,
probabilities are very low for any headline-worthy snow
accumulations to occur within the forecast area.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
Any morning valley fog vis obstructions are expected to clear
into an extended period of VFR through the TAF period for area
sites. A moisture starved upper trough passage is expected to
increase wind gusts unto the afternoon, where there is generally
a >70% of winds exceeding 20kts, and a >30% chance of winds
exceeding 30kts. Guidance shows the absolute maximum gusts
possible would be around 35kts; the probability of winds much
stronger than this is low.

Model odds show a 40% to 50% chance of MVFR at FKL/DUJ today
with the upper trough passage, though upstream observations are
showing considerably higher cigs; opted to leave out any
mention in TAFs for now. Outside of this, expect a deck to low-
to-mid levels VFR cu/stratocumulus to increase today with mixing
and the trough approach.

Into tonight, chances of cig restrictions drop to zero,
through-post frontal winds may increase wind shear in a 35kt to
45kt low-jet. It is more likely we decouple tonight, but should
we not, some gusts remain possible. Patchy valley fog could
develop, but is expected to be more muted with stronger winds,
and hence, was not mentioned.

.OUTLOOK...
High pressure will support high confidence (>80% chance) of VFR
Tuesday, but also enough boundary layer mixing for daytime wind
gusts to 20-25 knots both Tuesday and Wednesday. A weak
disturbance brings rain chances back to the area Wednesday into
Thursday, but confidence in any associated restrictions
impacting area terminals remains low.

&&

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

&&

$$

SYNOPSIS...Frazier
NEAR TERM...Frazier/Milcarek
SHORT TERM...Frazier
LONG TERM...Frazier
AVIATION...Milcarek