487
FXUS61 KPBZ 161628
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1128 AM EST Sun Nov 16 2025

.SYNOPSIS...
Lake-effect snow is expected north of I-80 Sunday night into
Monday. Another passing system brings a rain/snow mix Tuesday.
Temperatures rise midweek before rainfall returns late-week.

&&

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

- Rain changing to snow this afternoon
- Gusty winds continue; Wind Advisory for eastern Tucker
- Lake effect snow band likely north of Pittsburgh tonight into
  tomorrow; winter headlines in effect through Monday afternoon

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

Morning Update:

With confidence increasing that a lake-effect snow band will setup
within Forest County late tonight into early tomorrow morning,
the Winter Storm Watch was upgraded to a Lake-Effect Snow
Warning.

Intense snowfall rates are expected between 7pm tonight
through 7am Monday. Some areas could receive 1-2 inches per
hour. If snow bands ventures into neighboring counties,
Advisories may need to upgraded to Warnings.

Previous Discussion:

A tight pressure gradient and steep low-level lapse rates keep
gusty winds through Monday. Wind gusts will likely range from
35 to 40 mph. Wind gusts are expected to range from 45 to 55
mph into eastern Tucker County, where a Wind Advisory remains in
effect until 10 AM Monday.

Lake effect showers are expected to increase in coverage late
this morning. Precipitation type will start as rain and then
turnover to all snow, especially near and north of I-80, as
850mb temperatures fall about 10 degrees C over the course of
the coming 12 hours. Showers closer to Pittsburgh are expected
to be largely rain, with daylight temperatures in the low to mid
40s. By sunset on Sunday, little accumulation of snow is
expected with SFC temps largely unsupportive and a lower
likelihood of snowfall rates high enough to overcome these.

That changes as we move into Sunday night. 850mb temperatures
fall to as low as -7C to -9C. This allows for an around 20
degree C difference between 850mb and the lake surface
temperatures, generating very efficient lake effect snow. Model
guidance continues to point towards the generation of a dominant
lake band with a possible Superior/Huron/Erie triple
connection. Placement of this band remains more difficult to
forecast than its occurrence which seems highly likely. At this
time it seems most likely to strike northeastern Forest County
and to a lesser degree, northeastern portions of Venango,
Clarion and Jefferson Counties. The band looks to waver some but
could supply very efficient snowfall from around sunset Sunday
evening into the midday hours of Monday. At this time between
2-5" remains likely in areas that see some residence time of
this band but isolated totals up to a foot of snow seem possible
where the band sits for the longest time.

At this time Winter Weather Advisories have been issued for
Venango, Clarion and Jefferson Counties until Monday afternoon.
These counties will likely see a very sharp gradient in snow
totals from southwest to Northeast. If the snow band ventures
into any of these counties for a prolong period, they could be
upgraded to a Lake Effect Snow Warning.

Low temperatures Sunday morning vary widely from mid 40s south
and west to near freezing north and east. Daytime highs will
display a similar pattern nearing 50 in the southwest and
scraping 40 degrees northeast.

&&

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

- Lake-effect snow continues into Monday afternoon
- Gusty winds diminish through the day on Monday
- Another system crosses the region Tuesday returning a
  rain/snow mix
----------------------------------------------------------------

SFC and 850mb flow looks to back by late Monday afternoon,
shutting off the most efficient lake effect showers and leading
to a general drying trend.

The pressure gradient slackens meaningfully for the first time
in the forecast period Monday night and light winds overspread
the area. This, along with largely clear skies will result in
very efficient radiative cooling and low temperatures Tuesday
morning can be in the low to mid 20s across much of the region.
Areas that have a fresh snowpack on the ground may be able to
push this even further.

Cloud cover and POPs rise again by sunrise on Tuesday as
another disturbance races through the Ohio River Valley spurred
on by a 500mb shortwave. Precipitation may begin as snow across
the region, with residual dry air in the low levels allowing for
wet-bulbing. Through the day however, WAA strengthens and a
turnover to rain is expected by early afternoon. The system
exits east as quickly as it came and POPs begin to fall again by
Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
KEY MESSAGES:

- Above average temperatures mid to late week
- Rain chances rise again late week with another passing
  disturbance likely
-------------------------------------------------------------------

Long range ensembles favor height rises and ridge building
across the Ohio Valley as early as Wednesday morning. This
likely supports above-average temperatures during this period.
Despite upper ridge building, a lingering SFC trough could
support lower end rain chances (roughly 30%) through Thursday.

About 75% of long-range ensembles favor another trough dropping
down from central Canada and flattening the ridge by Friday
morning. At the SFC, there is a signal for another disturbance
emanating from the high plains to rise northeast through the
Great Lakes and drag fronts across the region Friday into
Saturday. Rain chances from this system rise as early as
Thursday night as the warm front is progged to cross the region.
POPs begin to fall off but not disappear by sunrise on Saturday
as the lingering affects of the upper trough could prolong rain
chances. By Saturday, long-range ensembles differ greatly in
the upper-level pattern and confidence in forecast outcomes
drops drastically.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...

Lake-effect showers will continue to cross portions of the
region this morning into Monday. At first, shower precipitation
type will likely start as rain and change over to snow.

Terminals that will likely be impacted will be FKL and DUJ. If
a snow band ventures over one and/or both of these terminals,
LIFR conditions could occur with poor visibility (less than
1/2SM) and reduced cigs. Elsewhere, the probability prolong
restrictions is considered low and VFR is likely.

Confidence in impacts at DUJ is fairly high, but probability is
lower at FKL, where snow showers may be more isolated.

With a tight pressure gradient, expected wind gusts to range
between 25 to 35 kts today into early Monday.

Outlook...
Lake effect snow band(s) may persist across the I-80 corridor on
Monday before diminishing Monday night.

Periodic restriction and precipitation chances are favored
through next weekend as an active weather pattern is likely to
continue.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory until 1 PM EST Monday for PAZ008-015-
     016.
     Lake Effect Snow Warning until 1 PM EST Monday for PAZ009.
OH...None.
WV...Wind Advisory until 10 AM EST Monday for WVZ514.

&&

$$

SYNOPSIS...Hefferan
NEAR TERM...Hefferan/AK
SHORT TERM...AK
LONG TERM...AK
AVIATION...Hefferan/Rackley