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000
FXUS61 KCTP 072144
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
444 PM EST Sat Dec 7 2019

.SYNOPSIS...
After a fair weather weekend, a volatile and stormy pattern is
expected during the second week of December. Temperatures are
forecast to surge well-above normal Monday and Tuesday,
followed by a sharply colder trend Wednesday into Thursday. The
brief warm-up will be accompanied by periods of rain which may
end as light snow Tuesday night. A mid to late week drying
trend will likely reverse by next weekend with another storm
system on the horizon.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Mainly clear skies expected tonight with min temps in the teens
and 20s.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Clouds increase on Sunday with max temps rebounding 5-10 degrees
over the western Alleghenies. Dry wx will hold during the day
with POPs steadily increasing later Sunday night into early
Monday morning. Leaned toward hires blend/HREF with highest
precip probs in the far southeast zones by daybreak. QPF will be
very light and with southeast flow could almost see a more
misty/foggy/drizzle type pattern developing. Thermal profiles
are very marginal particularly over the interior central mtns
where some spotty light frozen/freezing precip is possible
especially when considering wet-bulb effects. That said, sfc
temps generally AOA 32F suggest little to no impact as
predominant ptype becomes rain into later Monday morning.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Big temperature swings are expected during the period.
A significant warming trend is forecast early next week with
max temperature departures +10-15 degrees above normal
(widespread 40s and 50s). Unseasonably mild minimum temps are
forecast Monday night with departures on the order of 15-20
degrees above normal as the primary PWAT axis (with values
around +2 sigma) slides east across the region.

The mild surge will be accompanied by periods of light to
moderate rain Monday and Tuesday. Rainfall amounts between 0.50
to 1 inch are forecast early next week. The warm air and
rainfall will help to melt the snow over the Allegheny Front
into the Upper Susquehanna River basin. Areas of fog are likely
as the mild air moves over colder ground. Rises on
rivers/streams are expected and will need to monitor risk of
minor flooding across the northern tier. WPC indicates a MRGL
risk of rainfall heavy enough to cause flooding of small streams
and poor drainage areas over our far SW counties Monday into
early Tuesday.

It will turn sharply colder midweek as arctic air blasts into
the region. Temperatures will be on the decline over the NW
Tuesday afternoon (non diurnal over the NW half) and drop
quickly Tuesday night areawide. There will be some potential for
residual water or slush to freeze up quickly by Wednesday.
Highs are forecast to drop by 20-30 degrees between Tuesday and
Thursday, with minimum wind chills in the single digits and
teens Thursday morning.

There is also a chance that the cold air could catch up to the
back edge of the rain and result in a period of snow at the end
of the precipitation event on Wednesday. There should be some
lake effect snow that develops in the wake of the system, but
trajectories appear to be focused more into southwest NY.

Strong 1040+mb high pressure moves NE across the region Thu/Fri.
The more active weather pattern may continue into next weekend
with the GFS and ECMWF both showing a large, dynamic storm
system bringing some modified tropical air up the eastern
seaboard, potentially impacting portions of our region.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
VFR conditions this afternoon through 18z Sunday. Cirrus clouds
with cigs >25000ft will move through the airspace overnight.

Will have to watch potential for swrly LLWS of 40+ kts starting
in BFD Sunday afternoon/evening and overspreading the rest of
the area Monday afternoon into Tuesday morning, as a few waves
of low pressure pass to our west.

Cigs and vis will be reduced in periods of rain Monday and
Tuesday.

.Outlook...

Sun night...Lowering cigs. LLWS poss at BFD

Mon-Tue...Widespread SHRA/MVFR. IFR and LLWS poss. CFROPA Tues.

Wed...Restrictions NW half. Breezy NW wind.&&

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

&&

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

&&

$$
SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Lambert/RXR/Steinbugl
AVIATION...Banghoff/Colbert