Area Forecast Discussion
Issued by NWS State College, PA

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910
FXUS61 KCTP 051033
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
533 AM EST Mon Dec 5 2016

.SYNOPSIS...
A storm system will move in from the Gulf Coast states and bring
another period of a wintry mix of precipitation to the region
Tuesday and early Tuesday Night. Much colder air will move in
after a cold front passes on Wednesday. The end of the week will
feature a prolonged bout of lake effect snow and much-below
normal temperatures.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Last of the real/substantial precip rolling through UNV right now.
While this heavier precip may be SN for a brief time it is rain
here in the valley and the temps are warming everywhere. A
transition to a drizzly morning is in order. Patchy precip will
linger through sunrise - esp in the west. Wind already turning to
the west and becoming gusty in wrn PA. This may dry things up but
dewpoints are still in the m30s in NErn OH. Expect a little
clearing as downslope/warming starts this morning in the SE. Maxes
in the m40s look OK there, and in the u30s-l40s elsewhere.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
High pressure bubble goes right overhead tonight, but it moves
quickly away. Srn stream storm developing along the Gulf Coast
will continue to deepen and consolidate but flow does not buckle
all that much as the old upper low gets caught in the westerlies.
The main sfc low should stay well to the south. But, the secondary
low will move into the OH valley late Tuesday. The most difficult
part of the forecast is the p-type. Many factors pulling at the
forecasters this morning, including but not limited to:

+ Onset of precip - mainly later in the day unless one follows
the outlier/faster EC. This would argue for warmer temps, esp in
the C and NE zones.

+ Amount of warm air intrusion. Seems limited
at this time, but a brief period of FZRA is almost likely at onset
in the Laurels.

+ While much of the precip during the daylight may be snow, it
will likely be falling into a warmer blyr, and will need to fall
pretty heavily to accumulate. We are almost to the shortest days,
so solar help is waning. The coolest locations will be in the
central mtns.

At this time, we will keep the 12-24 hr forecast snow amounts at
or below 2" with the highest amounts over the NC mtns.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Tuesday night will be the end of the precip from the next big
thing. Precip should be tailing off and will effectively stop
before the cold air and front passes late Tues night and Wed
morning. A brief snow squall is possible with the frontal passage.
Winds will get more gusty, too. 8H temps late Wed will be -6C NW
to +1C SE. This is right about normal for mid- Dec, so will paint
the maxes as almost exactly climo.

High pressure nosing in from the southwest for a brief time on
Wed/Night will keep it generally fair. But a few SHSN may occur
in the extreme northern tier due to W winds. The coldest air does
not arrive until Friday. The cold adevection will kick off a LES
event which will last into the weekend. 1000-500H thickness drop
below 520dam - a pretty good indicator that most locations won`t
get to freezing during the days Friday and Sat. Many in the N/W
will not get to 25F. Wind chills will be near zero in the Laurels.
Just the SE valleys could make ol Frosty to sweat briefly in the
aftn.

Sometime in the weekend an upper level trough (Montana Clipper?)
will cross the Upper Great Lakes and may produce more-widespread
snow. The POPs will be highest across the north for now as the
flow is zonal/flat and little moisture will be added to the
syaytem

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Steadiest pcpon has moved east of the region, but lingering light
showers and areas of drizzle will persist into the post dawn
hours with accompanying ifr cigs. Lingering lower stratus
expected in the mountains of the west and north for much of the
morning, but elsewhere expect conditions to improve to VFR by
mid/late morning.

Outlook...

Mon afternoon/evening...No sig wx expected.

Tue...Mixed precip/low CIGs possible, especially late.

Wed...Lingering low CIGs possible.

Thu...Mixed precipitation event - low CIGs possible.

Fri...Blustery and much colder with NW mtn and Laurel Highland
restrictions in SHSN and areas of enhanced Lake Effect Snow.

&&

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

&&

$$
SYNOPSIS...Dangelo
NEAR TERM...Dangelo
SHORT TERM...Dangelo
LONG TERM...Dangelo/Ceru
AVIATION...Jung/Gartner



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