347
FXUS61 KCTP 271744
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1244 PM EST Thu Nov 27 2025

.SYNOPSIS...
* Gusty west to northwest winds and much colder temperatures to
  end the week
* Lake effect snow will result in significant Thanksgiving
  holiday travel disruptions across northwest Pennsylvania
* Scattered snow showers and a few squalls will impact the
  weather across the Central Mtns, Laurel Highlands and possibly
  the Middle Susquehanna Valley Thanksgiving Day into Friday
* A few periods of snow (Northern PA) and snow/or a wintry mix
  (Southern PA) late Saturday Night and Sunday
* A more significant/widespread winter storm possible Tuesday
  and Tuesday night

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Lake effect snow will be the primary and significant concern
across Northwest PA for this Thanksgiving Day. No changes were
made to the current Winter headlines for several counties in NW
PA or or the Wind Advisory for the Laurel and Wcent Mtns.

Mean low level flow to start the day will be from 250-255 deg,
which will keep the significant single band of heavy LES along
and just inland from the south shore of Lake Erie in NW PA and
SW NY.

This will be short-lived though today as slight veering of the
wind by 5-10 degrees will push the single, intense snow band
into Northern Warren and NW Mckean County by 12Z.

This LES band will transition to 2 or 3, long and more narrow
bands of LES, extending well to the east of RT 219 in NW PA by
late this morning. The bands will then waggle throughout the
next 36 hrs, but fetch will keep the heaviest accums over the
normal snow belt of Warren county and NWrn McKean county.

Limited Glake moisture and deep layer cooling will bring fairly
widespread flurries today across much of the Central and
Northern Mtns, Laurel Highlands and even the Middle Susq Valley
as the depth of the well mixed layer occupied by the dendritic
growth zone of -12C or lower increases from about a 1 kft
thickness this morning to around 2 kft by 00Z Friday.

Drying, low-level downslope flow across the Lower Susq Valley
will result in some significant breaks of sunshine in that part
of the CWA for the mid to late afternoon hours.

Temps today will display only a few to several deg F rise at
best across the Northern and Western Mtns considering the
deepening cold advection and widespread bkn-ovc skies, while
the Susq Valley sees a 6-8 deg F rise from morning lows.

Highs will range from the upper 20s to low 30s across much of
the Northern and Western Mtns to the lower 40s in the Greater
York, Harrisburg, Lancaster areas.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
The next concern would be if a long band from Lake Huron
eventually meets up with LE water and develops at least one
longer band that could extend deep into the CWA. At this point,
most models keep the large Huron-connected band well to the N
of UNV (and along the RT 6 corridor) later tonight through
daybreak Friday, with focus for the Central Mtns being placed
more on a Lake Superior/Nrn Lake Mich and Central Lake Erie
fetch producing another extensive band on a 285 to 90 deg axis
pointed at KDUJ, KFIG and KUNV by 12Z Friday.

There is potential for this band to become quasi-stnry for a few
to several hours which could result in locally 2-3 inches of
wind blown snow along a 15-30 mile stretch of I-80.

The big take-away: Snow for PA will be most-widespread and
heaviest on tonight and Friday AM.

The positions and strength of snow bands on Friday are
difficult to precisely nail down. There is some disagreement on
just how fast/completely the wind will back/turn to the west
and southwest and make the snow go away. Current forecast of
lower PoPs on Friday aftn is reasonable, but we may need to
delay the exit/ending of the snow for 6+ hrs.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
The lake effect snow pattern comes to an end Saturday morning
as low-level flow backs and high pressure begins to build in,
resulting in a lowering subsidence inversion. There is still
some uncertainty with speed/timing, but overall guidance agrees
in bringing another round of precipitation for the area on
Sunday. Thermal profiles appear to be cold enough to initially
support snow, then perhaps mixing with or changing to rain for
the last day of November. Unsettled weather will continue into
early next week as cold air in the middle of the country sets up
a strong baroclinic zone over the eastern US.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
A westerly-flow lake effect scenario has set up for the area
with the main concerns being flight category changes at KBFD in
SHSN and the gusty winds everywhere else.

Lake effect snow is making its way across northern PA with
intermittent flight category changes at KBFD from MVFR to IFR to
LIFR and back. Instead of a long narrow snow band, the area is
seeing more of a cellular cluster of heavier snow bursts as mid
and upper level winds break the snow bands apart as they move
farther from the lake shore. This will keep the ceilings and
visbility bouncing up and down at KBFD for the remainder of the
forecast period.

Elsewhere, gusty west winds will also continue through the
period. Winds will increase somewhat later today with some gusts
approaching 30KTS at times. Given the gusty nature, have left
out LLWS wording as these gusts would imply wind shear. Several
PIREPs indicate such across the area.

Winds at 700mb and 850mb begin to diminish Friday morning so
expect the lake snow coverage to decrease as well. Hoever,
enough moisture remains to leave the entire area with a
StratoCu MVFR ceiling through the end of the period.

Outlook...

Sat...Improving conds; diminishing winds with lingering snow
showers ending.

Sun...Light rain/wintry mix developing from west to east;
restrictions possible. Precip may turn to rain across the south
during the day.

Mon...Mixed/wintry precip likely. MVFR likely. IFR poss.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Lake Effect Snow Warning until 1 AM EST Saturday for PAZ004-
005.
Lake Effect Snow Warning until 1 AM EST Saturday for PAZ006.
Winter Weather Advisory until 1 AM EST Saturday for PAZ010-011.
Wind Advisory until 7 PM EST this evening for PAZ017-024-025-
033-034.
Winter Weather Advisory until 1 AM EST Saturday for PAZ037.

&&

$$

SYNOPSIS...Guseman/Lambert
NEAR TERM...Guseman/Lambert
SHORT TERM...Guseman/Lambert
LONG TERM...Gartner/Colbert/Bauco
AVIATION...Tyburski