Area Forecast Discussion - Northern


FXAK69 PAFG 182318
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
218 PM AKST Thu Jan 18 2018
.SYNOPSIS...
Aloft...
Broad long wave trough over the Bering Sea and mainland Alaska
will progress east with the long wave trough moving over mainland
Alaska Sat, then deepening through the middle of next week.
This means that the pattern is transitioning from a wet and much 
warmer and normal pattern now to near normal temperatures on the 
weekend, much colder than normal next week. 

A low aloft near Barrow will move north tonight. Weather
associated with this addressed in surface section below. 

A second low aloft near Yellowknife will move to Old Crow by 3pm
Fri and to near Barter Island Fri night. This will bring light
snow to NE Alaska.

A short wave trough along the West Coast of Alaska will move to
Point Lay to Bethel by 3am Fri, to Barrow to McGrath by 3pm Fri,
to Deadhorse to Minchumina by 3am Sat, and to Deadhorse to Denali
by 3pm Sat, then quasi-stationary into Sun. Cloudy skies with flurries
and light snow will occur east of the short wave, with precip
ending and skies clearing west of the trough.

Surface...
A 996 mb low near Barrow will move to 100 nm north of Barrow by
3am Fri as a 1004 mb low, to 300 nm north of Deadhorse by 3pm 
Fri as a 1009 mb low, and to 400 nm north of Barter Island by 3am
Sat as a 1012 mb low. An occluded front wrapped around this low 
then stretching to Inuvik will move north of the Arctic Coast 
tonight. Light snow will occur with the low and along the occluded
front. Winds have turned SW along the coast east of Barrow.

An occluded front in the NW Territory will move over NE Alaska
tonight and then dissipate in place through Sat. This will bring
1-2 inches of snow to NE Alaska.

An arctic cold front stretching from the low to Atigun Pass to
Minchumina will move to Barter Island to Denali by 3am Fri, 
to Inuvik to Isabell Pass by 3pm Fri, to Dawson to Mentasta Pass
by 3am Sat, and then east of the Alcan Border Sat. Expect light
snow along and west of this front. Expect 2-4 inches Tonight 
through Sat over the Eastern Interior. Snow will end west of the 
trough aloft mentioned above. Expect West winds 30g40 mph and low 
visibility in blowing snow along the front over NW Alaska and the 
North Slope along with the front. Issuing WWA for zones 201 202 
203 204 206 and 210 for this. Expect north winds 30g40 and blowing
snow with low visibility to develop in Brooks Range passes late 
night Fri and continue into Sat. Will issue WWA for for this in 
zone 218 as well.

&&
.DISCUSSION...
Vertically stacked low near Barrow initialize on models a bit 
southwest of where sat pic indicates. RAOBs at Barrow and 
Kotzebue missing at 12z this am could be reason for this. This 
means that in short term the vertically stacked low will be 
slightly northeast of model locations through this evening and
that winds and snow will spread across Arctic Coast a bit more 
quickly than models indicate, with winds in NW AK and North Slope
a bit stronger than models indicate through this evening as well.

Models similar through Fri, then the ECMF moves a low into NW
Alaska more quickly than the GFS and NAM. Favor the GFS from Fri
into weekend. From Mon through next weekend models show long wave
moving over mainland AK, though the ECMF is weaker and much 
further east with the trough from the middle of next week onward. 
At this time favor the GFS ensemble from Mon through next weekend.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Blizzard Warning for AKZ204.

Winter Weather Advisory for AKZ201-AKZ202-AKZ203-AKZ206-AKZ210-
AKZ218.

Heavy Freezing Spray Warning for PKZ210.

Small Craft Advisory for PKZ210.

Brisk Wind Advisory for PKZ215-PKZ220-PKZ225-PKZ230-PKZ235-
PKZ240-PKZ245.
&&

$$

JB JAN 18