Small Craft Advisory 103, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
214 PM AKDT Tue Aug 29 2017

.DISCUSSION...

Models...Doing well with the short term solutions. They start to
diverge in the extended periods, but a blend will provide a good
solution for those periods. Surface guidance initialized well
against the 29/18Z surface analysis.

Aloft...At 500 hpa...Long wave trough persists. Trough extends
south from a 509 dam low near the North Pole to a 535 dam low
near Point Barrow to a 532 dam low over Kodiak Island this
afternoon. Weak ridging across the state between the ranges today
will be squeezed out over the West Coast as the low near Point
Barrow dives south over Norton Sound by Wednesday morning, while
the low over Kodiak Island remains Stationary. Weak ridging will
persist over the eastern interior with the axis over the upper
Yukon Flats by Wednesday morning, and rotating northeast over the
eastern Arctic Coast by Wednesday evening. By Thursday morning
the longwave troughing starts to break down a bit as a 549 dam
high over the Dateline pushes ridging east across the Arctic
along 75n. At 850 hpa...Zero isotherm lies from Old Crow YT to
Shaktoolik to Gambell, and by Wednesday afternoon will lie from
Old Crow YT to Huslia to Bethel. Temperatures over the southeast
interior will be warmest ranging from +4 to +10 through Thursday.
Some spotty temperatures around -10C persisting over Arctic Plain
and central Brooks Range tonight.

Surface...Broad area of low pressure remains over the state.
A 998 mb low over the Beaufort Sea will move northeast into the
Canadian Archipelago tonight. Weak troughing extending southwest
across the state to a 976 mb low near Kodiak Island this
afternoon. Ridging from a 1026 mb high over the Siberian Arctic
has pushed east over the Arctic Plain and a 1011 mb high is
developing over MacKenzie Bay. The ridging will slide north as the
low moves northeast and the center will move to 500 nm north of
Barrow by Thursday afternoon. Leeside troughing develops tonight
north of the Alaska Range, gap winds kicking up as pressure
gradient tightens a bit Wednesday morning into Thursday morning.
The low near Kodiak will move slowly move north to the western
Alaska Range by Thursday at 993 mb low with a 996 mb low
developing over the Nulato Hills Thursday afternoon.

Arctic Coast and Brooks Range...Onshore flow continues. Expect
periods of rain and/or snow, areas of fog with poor visibility,
and low ceilings. North winds swinging around to northeast and
east diminishing from 10 to 25 mph to 5 to 15 mph for most areas.
Cold air persisting over the area, so another round of snow in the
Brooks Range as moisture streams north. Expect 2 to 4 inches of
snow at pass elevation and above.

West Coast and Western Interior...Windy, but otherwise relatively
quiet. Some high clouds being spun into the area this evening,
then some rain over the inland areas Wednesday. Heaviest rainfall
will be south of Galena and east of Anvik in the upper Kuskokwim
River Basin. Rainfall of 0.25 to 0.50 inch will be possible.
Patchy fog in the Middle Yukon Valley tonight. West of Galena
north to northeast winds will continue to increase this evening as
the gradient pinches over the area. Strongest winds will be in
the Bering Strait and nearshore waters as they increase to 15 to
30 mph with gusts on the outer Capes to around 50 mph. Inland
winds increasing to 5 to 20 mph. Temperatures not changing much.

Central and Eastern Interior...A few sprinkles around the
Fairbanks area and southeast to the Alaska Range this evening. To
the west and north of Fairbanks the rain redevelops and rainfall
amounts will range from 0.20 to 0.75 inch over the next 24 hours.
Some gusty northeast winds in the upper Porcupine River Basin and
into the Upper Yukon Flats with winds gusting to around 30 mph in
a few locations. In the Alaska range gap winds developing
overnight will continue into Thursday morning before diminishing.
Gap winds will be south at 25 to 35 mph gusting to 45 mph near
passes. For the remainder of the area expect winds to kick up a
little overnight with northeast winds 10 to 20 mph for a few hours
this evening.

&&

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

&&

.FIRE WEATHER...Cool conditions continue with Relative Humidity
values remaining above 40 percent.

&&

.HYDROLOGY...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Advisory for AKZ217.

High Surf Advisory for AKZ213.

Small Craft Advisory for PKZ200-PKZ215-PKZ220-PKZ225-PKZ240-
PKZ245.

Gale Warning for PKZ210.

&&

SDB AUG 17