Area Forecast Discussion
Issued by NWS Fairbanks, AK

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FXAK69 PAFG 021337
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
437 AM AKST Fri Dec 2 2016

.SYNOPSIS...
Aloft...
A long wave trough over mainland Alaska will persist through Sat
then move east Sun as a long wave ridge over the Bering Sea moves
east over mainland Alaska Sun. A series of short wave troughs will
move north over eastern Alaska through Sat in this long wave
scenario with snow and clouds over the eastern third of the
Interior. Clearing skies over the west side of the long wave
trough have brought temperatures into the 20 and 30s below in the
western Interior. Skies will clear over the Eastern Interior Sun
as the ridge builds east bringing much colder temperatures there.

A short wave trough stretching from McGrath to Nuiqsut will move
to Minchumina to Deadhorse by 3pm Fri and then stall through Sat.
Clouds and light snow are occuring east of the trough with mainly
clear skies to the west. There are bands of snow moving NE just
east of this trough that are causing periods of moderate snow
through this morning.

Surface...
A 1000 mb low in the MacKenzie May with an arctic cold front
stretching south to a 998 mb low near Burwash Landing and then to
Valdez. The Arctic front will remain in place through this
afternoon and then move east tonight. This has caused cold air
damming up against the Alaska Range and will cause a deep wedge of
cold air which moisture spreading north will over run.

Weak High pressure over the western Interior and Central North
Slope will build through through Sat night and then expand east
and continue to build over eastern Alaska Sun. Temperatures in
the 20s and 30 below under this high will spread east with the
high. By Sun night altimeter settings could rise to above 31.00
inches causing problems for some planes.

This high is causing moderate west winds over zone 204 now that
will increase to 25 kt this afternoon and persist through Sat. NW
winds gusting to 25 kt will develop through Alaska Range passes
and in the eastern Tanana Valley and near Eagle today and continue
through Sat.

A strong 960 mb low in the NE Gulf of Alaska will move to near
Gustavus by this afternoon and to near Whitehorse tonight. A
strong occluded front stretching ne from this low will move north
to Gulkana to Eagle by 3pm fri...to Valdez to Delta Junction to
Eagle by 3am Sat... to Denali to Fairbanks to Old Crow by 3pm Sat
and then dissipate Sat night. As this front moves north and over
runs the arctic front today and tonight it will cause snow to
spread nw over the eastern Interior. Snow will spread to Northway
early this morning...to Delta Junction by late morning and to
Fairbanks about noon today. Snow will taper off southeast of the
occluded front. Expect 3-6 inches of additional snow with this
feature from Fairbanks east today through Sat...with the heaviest
amounts in zones 224 and 226.

A cold front stretching from Barrow to Savoonga will
move to Barrow to Kotzebue to the Yukon Delta by 3pm Fri and then
weakening Fri night. Low level NW winds along and west of this
front will cause lake affect type snow showers along and west of
this front over northwest facing coasts today and tonight.

&&

.DISCUSSION...
Models initialize well at 500 mb when compared with RAOBs and
satellite imagery at 06Z Fri. At the surface all models miss the
994 mb low near Eagle and the 1002 mb low in MacKenzie Bay with
models 6-8 mb too high on the pressures in those areas. Expect
that surface pressures will remain lower along the Alcan Border
area today than models indicate which will cause stronger west
winds today than models indicate in the Eastern Interior and
along the Eastern Arctic coast near Kaktovik.

In the big picture models agree on the long wave pattern through
next Tue...so high confidence on cold weather moving into Eastern
Interior Sun night through Tue and possible longer.

&&

Coastal Hazard Potential Days 3 and 4...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory for AKZ220-AKZ221-AKZ222-AKZ223-AKZ224-
AKZ226.

Heavy Freezing Spray Warning for PKZ210-PKZ220-PKZ225-PKZ230.
&&

$$

JB DEC 16


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