Area Forecast Discussion
Issued by NWS State College, PA

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000
FXUS61 KCTP 171913
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
213 PM EST Sat Feb 17 2018

.SYNOPSIS...
Low pressure will track northeastward to the Mid Atlantic coast
by this evening. An anomalous upper level ridge will build off
the east coast next week, with a dying cold front pushing into
the state on Wednesday. Abnormally mild conditions will prevail
for much of next week. Temperatures will be more typical of
early Spring than mid Winter.

&&

.NEAR TERM /THROUGH TONIGHT/...
Clouds lowering and thickening at mid afternoon with snow
breaking out from southwest to northeast across the southern
half of centrla PA. Timing slightly ahead of earlier thinking,
but overall scenario in good shape with a widespread 2-4"
snowfall for most south of I80, 1 to 3 inches north, and
locally 5 or 6 possible in a stripe from the South Central
Mountains through the Lower Susq. where some 1" per hour
snowfall rates are possible late this afternoon through early
this evening as jet entrance region enhances the snowfall there
for a few hours. All snow expected except for the possible
exception of far southern Lancaster and York Counties which may
mix with or change to rain later this evening.

Expect the accumulating snow to taper off rather quickly in the
mid evening hours as low pressure passes off the Delmarva.
Lighter orographic snow is likely to linger over the
Alleghenies until after midnight with flurries continuing there
afterwards into the pre dawn hours.

&&

.SHORT TERM /SUNDAY/...
Freshly fallen snow and high pressure will make for a pretty
Sunday morning. Enjoy the snow cover while it lasts though
because afternoon temperatures will rise to the lower to middle
40s central and south, and even upper 30s north, promoting
plenty of melting. Early morning stratus over the
north...otherwise mostly sunny skies expected throughout the
day.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Made minor changes to the fcst package.

Main thing for Sunday night was to lower temperatures...given
new guidance and also that some snow will likely result in
temperatures falling off quickly after sunset.

Took out rain for early Monday morning...except for the far
southwest. This area likely to be above freezing. Points
further east will see rain later on Monday morning...given
time for temperatures to rise above freezing.

QPF for Monday and Monday night will be much lighter than the
event we had Thursday evening, as the warm front lifts quickly
northward.

Overall an anomalous upper ridge builds along the east coast
next week. Heights rise to 588 across southern PA at 500 mb
Tuesday. Much of the area will be well into the 60s Tuesday and
Wednesday...but could warm well into the 70s if winds mix down.

Slightly cooler later in the week...as a cold front slips
southward into the area...as high pressure builds over eastern
Canada and New England. Models keep the basic pattern the
same...so by next weekend...mild conditions could return.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
Snow into far southwestern PA now.

VFR conditions will quickly give way to MVFR and IFR conditions
by late afternoon and early evening...as snow moves into our
area.

Conditions should improve across eastern areas shortly after
Midnight...as the storm quickly moves out of the area. Some
lower clouds and light snow showers could linger across the
central and western areas to just after sunrise on Sunday.

Overall...not a bad day for Sunday. Lots of sun by late morning.
Winds will die down by late aft.

Some showers and lower clouds next week...mainly for a brief
time Monday...and later on Wednesday...but much of the time will
be dry with VFR conditions. Also on the mild side.

Outlook...

Mon...Restrictions return with some light rain.

Tue-Wed...Restrictions likely in rain showers, mainly NW at
times...and late Wed elsewhere.

Thu...Clearing north. Still a chance of showers north.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 2 AM EST Sunday for PAZ027-028-
050>053-056>059-063>066.
Winter Weather Advisory until 4 AM EST Sunday for PAZ024-033.
Winter Weather Advisory until 11 PM EST this evening for
PAZ025-026-034>036.

&&

$$
SYNOPSIS...DeVoir
NEAR TERM...DeVoir/Fitzgerald
SHORT TERM...DeVoir
LONG TERM...Martin
AVIATION...Martin


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