Small Craft Advisory 172, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
250 PM AKDT Wed Oct 25 2017

.DISCUSSION...
A very active pattern continues over Alaska.

Aloft at 500 hp, a strong long wave trough over the Bering Sea
and a broad ridge over central and eastern Alaska and the Yukon
will continue to amplify over the weekend. Deep and moist
southwest flow continues to push over the state and will continue
to bring periods mixed precipitation over a large portion of the
state.

The west coast continues to see periods of snow, freezing rain
and rain as well as strong winds. Snow quickly transitions to
freezing rain and then to rain behind a strong front that
continues to move north and east into the interior. Heavy snow,
strong winds and low visibilities have been the hallmark of the
fronts approach with a transition to freezing rain and then a
quick transition to rain as warm air moves in behind the front.

The western and interior will see lesser amounts of snow but will
also see longer periods of freezing rain where up to one quarter
inch of ice accumulation is expected through Thursday. Additional
ice accumulations are possible in the western interior Friday as
additional moisture moves into the area.

Over the central interior to the west and north of Fairbanks,
periods of snow and freezing rain will continue into and Friday.
To the east and south of Fairbanks an ongoing Chinook event is
expected to prevent precipitation from reaching the ground
however any weakening of the chinook or slight change in wind
direction aloft to the west would allow perception to reach the
ground as rain and would likely freeze on the cold soaked interior
ground and roads. There is the potential for periods of light
freezing rain through Friday over the southern portions of the
central interior. Continue to monitor.

On the north slope mostly clear skies will give wave to lowering
clouds and a chance of snow tonight and Thursday. Snow will
increase Thursday afternoon over the western Brooks Range and
western North Slope. Snow and blowing snow may push headline
criteria especially from Barrow west Thursday afternoon. Continue
to monitor.

The 12z model suite initialized well against the 12z surface
analysis as far as feature placement and strength. The 12z model
suite verified well against the 18z surface analysis. Model
spread continues to be reasonable in both the short range and the
mid range. Models continue to indicate typical amounts of spread
and run to run variability in the long range.

Coastal Hazard Potential Days 3 and 4...
1 to 2 foot storm surge values are forecast for the lower YK
Delta Coast and Norton Sound with 25 kt westerly winds late Friday
and into Saturday.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
High Wind Warning for AKZ223-AKZ225-AKZ226.

Winter Storm Warning for AKZ208-AKZ209-AKZ215-AKZ216-AKZ227.

Winter Weather Advisory for AKZ210-AKZ211-AKZ212-AKZ213-AKZ217-
AKZ218-AKZ219-AKZ220-AKZ221-AKZ225.

Heavy Freezing Spray Warning for PKZ220-PKZ225-PKZ230-PKZ235-
PKZ240-PKZ245.

Small Craft Advisory for PKZ210-PKZ215-PKZ220-PKZ225-PKZ230-
PKZ235-PKZ240-PKZ245.
&&

CCC OCT 17

Special Weather Statement
National Weather Service Fairbanks AK
117 PM AKDT Wed Oct 25 2017

AKZ218>226-261400-
Southeastern Brooks Range-Upper Koyukuk Valley-
Yukon Flats and Surrounding Uplands-Central Interior-
Middle Tanana Valley-Deltana and Tanana Flats-
Upper Tanana Valley and the Fortymile Country-Denali-
Eastern Alaska Range-
Including Arctic Village, Wiseman, Coldfoot, Chandalar DOT Camp,
Iniakuk Lake, Allakaket, Hughes, Bettles, Caribou Mountain,
Gobblers Knob, Fort Yukon, Venetie, Central, Circle,
Stevens Village, Beaver, Chalkyitsik, Birch Creek,
Circle Hot Springs, Eagle Summit, Twelvemile Summit, Nenana,
Anderson, Tanana, Minto, Manley Hot Springs, Rampart,
Lake Minchumina, Livengood, Fairbanks, Fort Wainwright,
Eielson AFB, Ester, North Pole, Moose Creek, Two Rivers, Fox,
Chatanika, Chena Hot Springs, Sourdough Camp, Salcha,
Delta Junction, Fort Greely, Harding/Birch Lake, Dry Creek,
Dot Lake, Healy Lake, Tok, Tanacross, Eagle, Tetlin, Northway,
Alcan, Chicken, Boundary, Healy, Denali National Park,
Carlo Creek, Kantishna, Mentasta Lake, Black Rapids,
Donnelly Dome, Trims DOT Camp, Eagle Trail, and Mineral Lake
117 PM AKDT Wed Oct 25 2017

...Slippery Over Interior Alaska through Friday...

A strong weather system in southwest Alaska will continue to spread
snow, and freezing rain and warm temperatures to the area west of
Fairbanks this evening, and is expected to continue through
Thursday night. Up to 4 inches of snow, and up to one tenth of an
inch ice accumulation is possible over the Parks Highway from
Nenana south, and over the Elliott Highway from Livengood west.
Over the Dalton Highway, between 4 and 7 inches of snow is
expected through Thursday night. This will make these highways
very slippery.

From Fairbanks east, there is a chance of freezing rain tonight
through Thursday night. Strong chinook winds blowing over the
Alaska Range this evening through Thursday are expected to
prevent precipitation from Fairbanks east from this evening
through Thursday, however if any precipitation does occur it
could fall as freezing rain and make roads very slippery.

CCC