465
FXUS61 KCTP 101131
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
631 AM EST Mon Nov 10 2025

.SYNOPSIS...
* Wintry precipitation will continue to fall over the north and
  western highlands as temperatures fall on the back side of the
  departing surface low.
* Lake-effect and upslope snow showers will be heaviest Mon
  night into Tues, along with the coldest temperatures of the
  season thus far.
* Temperatures should begin to moderate by late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A deep cold airmass will continue to mix down to the surface
and intrude into Central PA this morning, with the morning lows
on track to dip into the low 20s across the NW highlands. This
will be a stark difference to the Lower Susquehanna Valley with
their lows only expected to reach the low 40s as the milder air
retreats southeast. The surface low from Sunday continues to
work its way up through New England. Upslope and lake effect
snow has begun to fall on the backside of this low where surface
temps have already dropped below freezing. No significant
snowfall is expected during the early morning hours today;
however 1-2 inches of snow could fall across Warren and McKean
counties by this late afternoon.

The cloud-layer flow moving across the lakes on Monday will be
light and directionally-sheared at first, then settle into a
more-stacked NW direction. Lake induced CAPE (51F lake water at
ERI) could reach into the 1000J range with clouds tops in the
5-10kft range. However, the cross-fetch is short at that angle
and would likely keep all but NWrn Warren Co from getting much
accum, esp as temps get close to freezing (and the sun makes
the ground/sfc slightly warmer). Anywhere further south or east
of Warren Co will struggle to see too much in the way of snow
during the day as the extent of the moisture transport from Lake
Erie will struggle to extend beyond NW PA during the day.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
As the sun lowers, the flow will back to west a little and get
a significant addition of Lake Huron moisture. This two-lake
fetch and a llJet of 40-45KT will be pointed right into
Warren/McKean Cos for much of Mon night (and into Tues). The
SLRs thru the period will lower to about 17:1 in the nrn mtns.
So, it`s not out of the question for the healthy band/bands to
drop >6" in Warren Co as the moisture rolls uphill. Not so sure
about McKean and Potter Cos, as they are farther from the lakes
and the moisture might not last that long/far into the CWA. The
amount of snow reaching that far south will all depend on the
strength of the Huron connection.

At the same time, the upslope flow into the highest hills of
Somerset Co (and all of PA, really) moistens up again as the
flow backs there, too, and brings the best moisture back N from
WV/MD. The residence time of the (combined) best moisture and
uplift over the Laurels looks short, though. Thus, additional
snowfall Mon night and early Tues is very much in question.
Also, the lower 2/3rds (elevation-wise) of the county will
likely get (way) less than 3" for the whole stretch. So, we`ve
decided not to issue an advisory for Somerset Co at this point
in time. Confidence has increased for the northwest, and a lake
effect snow warning has been issued for Warren Co. Additionally,
confidence is highest in Elk and McKean Cos also seeing 3+" of
snowfall overnight tonight, thus an advisory has been issued for
those counties. Monday night into Tuesday morning will also
feature the coldest temperatures of the week, and gusty winds
will place windchills into the single digits for most of our
northern and western zones.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Upper-level troughing will remain in place through the end of
the week, keeping the chance for rain and snow showers in the
forecast each day through Friday, especially over northwest PA.
A tight pressure gradient will allow for winds gusts in the 30
to 35 mph range Wednesday, with some guidance suggesting the
potential for gusts over the Laurel Highlands to approach 40 to
45 mph.

The December-like cold airmass is forecast to retreat later in
the week, with temperatures returning closer to seasonal
averages. High pressure attempts to briefly build in from the
west which should keep us mainly dry into the beginning of the
weekend, but uncertainty increases by Sunday regarding the
timing of an approaching frontal system.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Chilly northwesterly flow will maintain borderline IFR/MVFR
cigs across the Allegheny Plateau (BFD/JST) today, with
occasional -SHSN. Southeast of the Allegheny Front, MVFR cigs
this morning over the central mtns (AOO/UNV/IPT) should become
low-end VFR this afternoon. For the lower Susq Valley (MDT/LNS),
predominantly VFR cigs are expected this afternoon.
Northwesterly winds will occasionally gust 20+ kts areawide
today.

We could see a period of intensification of the snow shower
activity across the Allegheny Plateau tonight, as a multi-lake
snow band is expected to develop. This was hinted at in the TAFs
with reduced vsbys at JST & BFD overnight.

Tuesday will be blustery, with gusts to 30 kts possible. Snow
shower activity will persist across the Allegheny Plateau.

Outlook...

Wed-Thu...-SHSN and occasional restrictions continue across NW
PA; becoming VFR elsewhere. Breezy W/NW winds continue areawide.

Fri...Some improvement expected, with winds diminishing and
lingering -SHSN across NW PA diminishing as well.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Lake Effect Snow Warning from 10 AM this morning to 1 PM EST
Tuesday for PAZ004.
Winter Storm Watch Tuesday afternoon for PAZ004.
Winter Weather Advisory from 10 AM this morning to 1 PM EST
Tuesday for PAZ005-010.

&&

$$

SYNOPSIS...Lambert/Bowen
NEAR TERM...Lambert/Bowen
SHORT TERM...Dangelo/Bowen
LONG TERM...Bauco
AVIATION...Evanego