Weather Service Report


187 
FXAK69 PAFG 231559
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
659 AM AKST Sun Feb 23 2020

SYNOPSIS...
Highlights are:
Cold winds chills, SE winds 15 to 25 mph and low visibility in
snow and blowing snow along the West Coast will taper off by 
afternoon as winds decrease and temperatures increase. Cold winds 
chills in zone 201 will continue through Mon AM, and spread to 
zone 202 from midnight tonight through Mon AM. 

Light snow over the Eastern Interior will diminish from the west
today. The Alaska Highway from Tok to the Alcan Border with see NW
winds 15 to 25 mph and snow and blowing snow today. The 
Richardson Highway from Trims Camp south, and the Parks Highway 
south of Denali Park Entrance will see similar conditions today.

Clearing over the Western and Central Interior has allowed temps
to fall into the 20s and 30s below this morning, with these cold 
temps moving into the Eastern Interior tonight. Expect well below
normal temps most of Northern Alaska this week. 


Aloft...
A strong trough aloft from Wrangel Island to the Eastern Gulf of
Alaska will move to Utqiagvik to Big Delta by 3pm Sun, to Barter 
Island to Northway by 3am Mon, and east of the Alcan Border on 
Mon. Light snow east of this trough will taper off along the 
trough with clearing west of the trough. Expect an inch or less of
snow with this over the Eastern Interior today. Surface temps 
will fall into the 20s and 30s below in the clearing west of the 
trough.

A ridge aloft stretching from the Western Gulf of Alaska into the
southeast Bering Sea will build over southern Alaska Mon and Tue. 
This will keep skies partly to mostly cloudy, and keep most clouds
and weather over the West Coast and North Slope for Mon and Tue.

850 MB temps are colder than -20C over most of Northern Alaska,
with warming over Western Alaska Sun and Mon, with slight warming
over the remainder of Alaska Mon night and Tue. 


Surface...
A 997 mb low near Wrangel Island will move north today and 
tonight. A low pressure trough that lies from this low to north of
Utqiagvik to MacKenzie Bay will move north tonight and Sun.
Flurries and light fog along this feature will move north of the
coast this afternoon. 

A weather front from the Wrangel Island Low  Point Hope to the 
Bering Strait then southwest will move east to Barter Island to 
the Bering Strait to a 1018 mb low in the Gulf of Anadyr by 3pm 
Sun, with that low moving to near POint Hope as a 1023 mb low by 
3am Tue. There is snow and blowing snow, and SE winds 15 to 25 mph  
along this feature over the West Coast now that will taper off
this afternoon. Snow will redevelop along the front tonight and
Mon bringing snow to zone 213 tonight and Mon and to NW Alaska on
Mon night and Tue. Expect 1-3 inches of snow with this.


&&

.DISCUSSION...
Models verify well aloft at 00Z, and show similar solutions aloft
through 3pm Mon. After that time, the GFS and NAM have a short 
wave in the Gulf of Alaska further east than the ECMF. At this 
time favor the GFS and NAM solution. Due to the strong dynamics 
associated with this feature which would allow it to dig into the 
ridge, we favor the GFS and NAM solutions over the ECMF for Mon 
night and Tue.

At the surface at 06Z, the low near Wrangel Island it about 8 MB
deeper than any models indicate, and the wave near the Bering
Strait is also several MB deeper than any models indicate. Expect
lower pressures than models indicate in those areas to persist 
through noon today, then to come more in line with models tonight
as the Wrangel Is low moves north. The affect of this is that
winds along the West Coast are much stronger than models indicate
now, especially along the wave low near the Bering Strait. Those 
winds should remain stronger than models indicate through this
afternoon, then come more in line with models tonight. 

With precipitation, models show similar solutions through Mon, 
with slight differences on Mon night and Tue. We will use a blend 
of model precip fields for pops and amounts. All the models are 
too low with pops along the West Coast now. We will bump pops up 
to likely along the West Coast west of Golovin and Kivalina where
precip is occuring now, with likely pops moving into the 
remainder of the West Coast this morning. 

Bottom line is we will use a blend of the NAM, GFS and ECMF for
precip but bump up pops to likely today along the West Coast, and
we will use a blend of the NAM and GFS for surface temps and
winds, but increase winds 10 kt (and 15kt at Capes) in a narrow 
band ahead of the incoming wave along the West Coast today. 

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Wind Chill Advisory for AKZ201-AKZ202-AKZ207-AKZ209.

Winter Weather Advisory for AKZ213-AKZ214.

Brisk Wind Advisory for PKZ200-PKZ210-PKZ220-PKZ225.
&&

$$

JB FEB 20

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Western Regional Climate Center, wrcc@dri.edu