Small Craft Advisory 83, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
242 PM AKDT Thu Aug 10 2017

.DISCUSSION...
A weather front sweeping down from the northwest Arctic will
bring active weather to western and northern Alaska through the
weekend. Colder air is still expected to move into the state but
not as extensive as previously thought. Models are in good
agreement with the large scale synoptic features aloft in the
short term but begin to stray apart with solutions early next
week. A closed upper level low over Bristol bay will progress east
to the Alaska Panhandle by Sunday as a strong upper level trough
digs southward from the Arctic into the west coast. This trough
will drift east across the Interior and bring generally unsettled
weather to much of the forecast area on Sunday.

At the surface, models have had a difficult time coming to a
common solution for the track of the low pressure center
currently near Wrangel Island. All models are now in line and
rapidly sweep this low east tonight to pass about 150 nm offshore
of Barrow as 992 mb low and then continue northeast through
Friday night. A trailing weather front associated with this low
will move into the northwest Arctic coast this evening and the
remainder of the west coast on Friday. A broad area of low
pressure extending from Kotzebue Sound south to Norton Sound and
the remnant front will perist into Saturday.

As this front moves onshore, it will spread significant rainfall
into western Alaska which will continue over the west and
northwest coast into Saturday. Strong cold air advection and north
winds behind the front will impact this region as well. The colder
air will spread east along the North Slope and Brooks Range on
Saturday and Sunday bringing some accumulating snowfall,
especially to high elevations. The airmass and eastward extent of
the cold air is not as strong as orignally expected, so heavy snow
in the eastern Brooks Range is less likely but a few inches of
snow are still anticipated from the Dalton Highway westward,
including Atigun Pass. In addition to cooler weather and some rain
and snow, north winds 25 to 35 mph with higher gusts are expected
in the Brooks Range.

North winds 25 to 35 knots over the Chukchi and northern Bering
Sea will develop Friday after the frontal passage and perist into
Sunday. This will bring elevated surf to north facing coastlines
from Point to Saint Lawrence Island. For the northern Seward
Peninusla, the trajectory is slightly northeast which is less
favorable for any minor coastal flooding and only elevated surf
and some minor beach erosion is anticipated for Shishmaref.

Coastal Hazard Potential Days 3 and 4...
Strong north to northeast winds will persist Sunday and Monday
from the Beaufort Sea coast to Saint Lawrence island. Elevated
surf will likely continue to be an issue on north facing
coastlines.

&&

.FIRE WEATHER...
No concerns at this time. Relative humidities in the eastern
Interior will rise into the 30's and 40's on Friday. Southerly
winds will develop through Alaska Range passes this weekend but
relative humidities will increase as showers move into the area.

&&

.HYDROLOGY...
In addition to the heavy rain associated with the incoming west
coast weather front, a disturbance moving northwest through the
western Interior will bring 1-2 inches of rain tonight and Friday
to the south slopes of the western Brooks Range in the upper Kobuk
and Noatak River basins. Rain will persist over this area. Sharp
rises are expected on small streams and rivers in tonight and
Friday with bankfull conditions possible. Elsewhere, 1-2 inches of
rain is also expected over the southern Seward Peninsula Friday
night and Saturday. Flooding continues on the road to Tetlin
Village near Tok from the Tanana River. The Tanana River level will
remain steady through the weekend so minor flooding will continue.

&&

AUG 17