Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 180332
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1132 PM EDT Sun Mar 17 2024

.SYNOPSIS...
An upper level trough will swing over Pennsylvania Monday,
followed by a reinforcing shortwave and associated cold front on
Wednesday. High pressure is likely to build over the area
Thursday. A dying cold front is likely to approach from the Grt
Lks late next week, as a southern stream shortwave passes well
south of the state.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
The focus for the rest of the night will be over the NW Mtns,
where falling heights ahead of an approaching upper trough will
likely support additional snow showers late tonight. Inversion
heights will remain fairly low, so anticipate only minor
accumulations of up to an inch over Warren/Mckean counties.

Cold advection behind the front should result in steadily
falling temps overnight, with min temps by dawn ranging from the
mid 20s over the NW Mtns, to the mid 30s across the Lower Susq
Valley.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
The upstream mid/upper level trough will drift over the region
late Monday, resulting in a chilly and unsettled Monday.
The combination of falling heights and diurnal heating is
progged to result in steep lower tropospheric lapse rates and
even a bit of cape by afternoon, resulting in scattered snow
showers and even a few heavier squalls over the northwest
counties. Latest CAMS indicate mainly cellular convection, due
to lack of significant shear or a strong front to focus
convection. Progged surface wet bulb temps indicate air temps
could fall several degrees below freezing during any squalls
over the Allegheny Plateau, so can`t rule out locally hazardous
travel in this area during the PM hours. See no reason to
deviate from NBM max temps Monday, which range from the mid 30s
over the higher terrain of the Alleghenies, to the mid 40s over
the Lower Susq Valley.

Large scale subsidence behind the trough should cause any snow
showers to end over the eastern half of the forecast area.
However, a cold west-northwest flow should generate lingering
lake-enhanced, orographic snow showers over the Allegheny
Plateau. Relatively low inversion heights should keep additional
accumuations light (generally less than 1 inch based on model
qpf).

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Latest guidance continues to track a clipper north of the
region Tuesday night into Wednesday. Backing flow ahead of this
feature should result in a break in the lake effect activity
early Tuesday. However, warm advection along the attendant low
level jet is likely to support some light snow across primarily
the N Mtns Tuesday PM. Latest guidance indicates accumulations
of less than an inch.

The passage of the trailing cold front Wednesday should be
accompanied by scattered snow showers, a few of which could
survive into the Susq Valley due to strong forcing ahead of the
upper level shortwave. Steep lower tropospheric lapse rates
indicate the potential of some heavier snow squalls, mainly
across the N Mtns. Fair, but still cool, weather appears likely
Thursday, as the trough lifts out and surface ridging builds in
from the Grt Lks.

Medium range guidance suggests a few rain showers are possible
Friday, mainly over the N Mtns, associated with the approach of
a dying cold front. The bulk of guidance tracks a more
significant southern stream shortwave and associated area of
low pressure well south of PA next weekend. Therefore, fair and
seasonal conditions currently appear likely next Sat/Sun.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Generally VFR to ocnl high end MVFR cigs are expected for the
northern and western mountains for the rest of this evening with
ocnl -SHRA (mixed with or falling as -SHRA in the valleys),
while VFR category sct- bkn clouds will be found across the
central and SE part of PA.

Borderline VFR/MVFR cigs could spill into the central mtns
(AOO, UNV, IPT) during the late evening hours as cooling aloft
occurs with the approach of a few upper level disturbances. The
Lower Susq Valley (MDT, LNS) should remain VFR right through
tonight and Monday.

West-northwesterly wind will frequently gust between 20 and 25
MPH this evening, before subsiding by 5-10 mph overnight then
picking back up to similar speeds and gusts that we experienced
today.


Outlook...

Monday-Friday...Periodic snow showers and reductions, primarily
across the higher terrain of northern and western PA. This will
be enhanced by reinforcing shots of unseasonably cold air and
gusty W/NW winds. West to northwest wind gusts could peak in the
35 to 40 mph range on Wednesday.

&&

.CLIMATE...
Astronomical Spring (vernal equinox) begins on Tuesday March 19
at 11:06 PM EDT.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Fitzgerald
NEAR TERM...Fitzgerald
SHORT TERM...Lambert/Fitzgerald
LONG TERM...Fitzgerald
AVIATION...Lambert
CLIMATE...Steinbugl


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