769
FXAK69 PAFG 031436
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
636 AM AKDT Fri May 3 2024

.SYNOPSIS...
The North Slope will remain colder than normal with periods of
flurries and fog through the weekend. Expect scattered snow
showers over the Eastern North Slope late tonight to become
numerous snow showers over the Central and Eastern North Slope on
Sat into Sun with several inches accumulation. This will cause low
visibility in blowing snow from Anaktuvuk Pass East late tonight
through Sun AM.

The West Coast and Western Interior will have temperatures warmer
than normal through Sat south of Huslia, with cooler than normal
from Huslia north. Much colder temperatures will move over the
West Coast on Sun and over the Western Interior on Mon. Generally
dry conditions over Western AK now will see scattered showers move
north over SW AK today, with scattered showers over the Western
Interior tonight with scattered to numerous showers of SW AK, then
scattered to numerous showers over most of the area other than NW
AK on Sat and Sat night, then taper off to isolated to scatted
showers on Sun.

The Eastern Interior will see temps cooler than normal north of
the White Mountains today, while south of the White Mountains will
see southerly Chinook winds blowing across the Alaska Range
bringing dry, windy and warmer than normal conditions this
evening that will continue through Sat night with the strongest
winds late Fri night and Sat AM. Isolated to scattered snow
showers will develop over the Northern Interior tonight, and
increase to scattered to numerous on Sat and Sat night before
becoming isolated to scattered showers over all of the Eastern
Interior on Sun. Could see several inches of snow north of the
Yukon River from late tonight into Sat night.


&&

.DISCUSSION...
At 00Z aloft, the NAM and GFS initialize 10-20 meters to low on
500 mb heights over AK south of the Arctic Circle, while the ECMWF
and Canadian models initialize well over AK. As a result the
Canadian and ECMWF models maintain a slightly stronger ridge aloft
over the Interior today through Sat compared to the GFS and NAM,
and slightly stronger southerly chinook winds over the Alaska
Range today through Sat as well. Other than the Eastern Interior,
models show similar solutions aloft through 4am Sun, then the
ECMWF. After that time the NAM and GFS move a low aloft from NW
Alaska south over the Bering Sea more quickly than the ECMWF and
Canadian models with the ECMWF being the slowest solution. Given
the better initialization of the ECMWF and Canadian models, favor
the ECMWF and Canadian models for features aloft through 4am Sun,
then the ECMWF for Sun PM into Mon.

The long wave pattern consists of a deep trough over the Beaufort
Sea, a ridge over NW Canada Alaska and the Chukchi Sea and a
trough over the Bering Sea. A strong short wave dropping south
from the Beaufort Sea south over NW AK today and tonight, and
another strong short wave moving from the Bering Sea over SW
Alaska will cause the long waves to merge over the Beaufort Sea,
Western Alaska and the Bering Sea tonight with a ridge over NW
Canada and Eastern AK. The trough will move over Western AK on
Sat, then become negatively tilted from the Bering Strait to the
Gulf of AK on Sun. This will cause southerly Chinook flow aloft
across the AK Range to increase today, peaking out late tonight
and early Sat, then turning southeast and weakening Sat night and
Sun.

With precipitation, will use a blend of models. See above synopsis
for details.

At the surface at 06z, models resolve most surface features well
except that all models are 2-3 mb too weak on the surface high
over the Copper River Basin. Models show similar solutions at the
surface through Sun. Will use a blend of the Canadian and ECMWF
for surface features through Sun since they are preferred
solutions aloft. Will see NE winds 25-35 kt over St Lawrence Is
and the Bering Strait, spreading to the Point Hope area today, and
spreading to the Western Brooks Range tonight then continuing
into Sun. Expect south winds 15 gusting to 25 mph to develop along
the North Slopes of the Alaska Range today, increasing to 30 mph
gusting to 45 mph tonight then continuing into Sat, then
decreasing Sat PM into Sun AM. This could cause near Red Flag
conditions from Delta Junction south late this afternoon and
Evening, with little RH recovery there tonight, with Red Flag
conditions possible there on Sat.


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


&&

.FIRE WEATHER...
An Arctic cold front that lies from Eagle to Fairbanks to Norton
Sound will move north to Circle to Galena this afternoon, then to
Arctic Village to Norton Sound by 4pm Sat, and to Arctic Village
to the Yukon Delta by 4pm Sun. Scattered showers will occur along
this front this evening and become numerous along the front late
tonight and Sat.

A thermal low pressure trough over the Alaska Range will move to
Minchumina to Chicken by 4pm Fri and then remain in place through
tonight. Temperatures will warm to the upper 50s and lower 60s with
RH falling to 20-30 percent along this feature over the Tanana Valley
today.

A strong low in the Southern Bering Sea will move to the southeast
Bering Sea tonight, into Bristol Bay on Sat and into the Gulf of
Alaska on Sun. This will cause southerly Chinook winds develop
across the Alaska Range starting late today then continuing into Sat,
then decrease Sat night.  This will bringing dry, windy and warm
conditions to the Tanana Valley this evening through Sat night.
Expect south winds 15 mph gusting to 25 mph to develop along the
North Slopes of the Alaska Range today, increasing to 30 mph
gusting to 45 mph tonight then continuing into Sat, then
decreasing Sat PM into Sun AM. This could cause near Red Flag
conditions from Delta Junction south late this afternoon and
Evening, with strong winds and little RH recovery there tonight,
and then with with Red Flag conditions possible from Delta Junction south
on Sat.

Isolated to scattered showers are expected over most of the
Eastern Interior on Sun as the Chinook ends.

&&

.HYDROLOGY...
The Yukon River near Eagle continues to have high water and a
minor ice jam in place with ice in place down river from Eagle.
We have kept the SPS in place.

The Tanana River is partially ice free and now flooding is
expected.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ804-805-808-810.
     Winter Weather Advisory for AKZ809.
PK...Small Craft Advisory for PKZ802-852.
     Brisk Wind Advisory for PKZ803.
     Small Craft Advisory for PKZ804.
     Brisk Wind Advisory for PKZ805.
     Small Craft Advisory for PKZ806.
     Heavy Freezing Spray Warning for PKZ806-816.
     Brisk Wind Advisory for PKZ807-810.
     Brisk Wind Advisory for PKZ809-813-814-860.
     Gale Warning for PKZ811-856-857.
     Brisk Wind Advisory for PKZ812-858.
     Gale Warning for PKZ816-817-851-854.
     Brisk Wind Advisory for PKZ850-853.
     Brisk Wind Advisory for PKZ859-861.
&&

$$

JB