Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 212004

Area Forecast Discussion
National Weather Service State College PA
404 PM EDT Wed Mar 21 2018

Long-duration, early spring snowstorm will continue to impact
south central Pennsylvania through Wednesday evening. The rest
of the week will feature cooler than average temperatures and
occasional flurries. The weekend now looks to be dry as the
next weather system passes to the south of PA.


Areas of moderate to locally heavy snow will continue across
south- central PA through late evening. This early spring snow
storm has evolved very slowly, allowing heavy, wet snow to pile
up/weight on trees, increasing the risk for sporadic power

Heaviest snow will shift south/east with time into the lower
Susquehanna Valley this evening before tapering off from west
to east early tonight. Final storm totals will range from 10 to
20 inches and will make this the heaviest snow event for the
2017-18 winter season. A check of snowfall records at
Harrisburg indicates a 2-day snowfall over 1 foot would crack
the top-10 2-day March snowfalls, with the benchmark of course
being the 1993 "superstorm."

Webcams and social media reports indicate road conditions are
variable (wet, slushy, snow covered) with heavier rates offset
by relatively warm pavement surfaces and time of day/year.
Expect travel impacts and disruptions to continue through the
evening commute. In addition, watch out for slick spots on
untreated roads, sidewalks and elevated surfaces as areas of
slush and standing water from melted snow will freeze (minimum
temps in the 20s).


Models showing a trailing shortwave diving southeast across the
region on Thursday. Upper level diffluence ahead of this feature
should result in a fair amount of cirrus. Low PWATS and temps
aloft not cold enough to generate moisture flux from the Grt
Lks, so not anticipating anything more than scattered flurries
across the Laurel Highlands.

NBM/Superblend indicating max temps Thursday ranging from the
low 30s over the highest terrain of the Alleghenies, to the low
40s in the Susq Valley. However, a tight pressure gradient west
of coastal low will produce gusty winds, making it feel even
chillier. Bukfit soundings support frequent gusts between


All models tracking closed upper level low southeast across Pa
on Friday, likely supporting scattered, diurnally-driven snow
showers and flurries, mainly over the northern and western

After that, focus will shift toward low pressure lifting out of
the Miss Valley next weekend. NAEFS/ECENS indicate this system
will likely pass too far south to affect central Pa, but will
maintain the slight chance for a period of snow.

After that, all med range guidance is showing upper level
ridging building into the region, supporting a high confidence
forecast of fair weather and warming temperatures early next
week. A dying cold front could approach the area late Tuesday,
potentially spreading showers into the state.

Temperatures should remain below seasonal normals through most
of the long term forecast, as upper trough remains over the
northeast conus. However, moderation is anticipated by Tue/Wed,
as upper trough lifts out.


Widespread restrictions in snow from winter storm will persist
across the southern half and especially southeast into the early
evening. But trend will be for improving conditions to drop
down from the north and work in from the west as storm pulls
away. By late evening, VFR conditions should take hold in most
locations, though increasing northerly flow should keep ceiling
restrictions in the higher elevations of the west and possibly
parts of the southern mountains.


Thu...No sig wx expected.

Fri...Cig restrictions poss NW.

Sat-Mon...No sig wx expected.


Winter Weather Advisory until 8 PM EDT this evening for
Winter Storm Warning until 8 PM EDT this evening for


NEAR TERM...Steinbugl
SHORT TERM...Fitzgerald/RXR
AVIATION...RXR is the U.S. government's official web portal to all federal, state and local government web resources and services.