Small Craft Advisory 18, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
340 PM AKDT Sun Apr 22 2018

.SYNOPSIS...
Aloft...
A long wave pattern consisting of a trough over the Bering Sea
with a ridge over NW Canada and northern Alaska will progress east
through Wed to a trough over the Eastern Bering and West Coast of
Alaska and Ridge over Western Canada. A series of progressively
stronger short wave troughs will move north over Alaska in this
flow, with each trough cutting into the ridge and pulling the
trough east. There will be occluded fronts moving north coincident
with each strong short wave.

This pattern will cause increasingly strong south flow over
Northern Alaska with temperatures warming to well above normal by
Tue. This will cause increasing chance of rain and snow along the
West Coast and Western Interior Mon PM into Tue, while the
Eastern Interior has increasing Chinook flow, with very warm
temperatures and very strong winds over the Tanana Valley Mon
night and Tue.

Surface...
A ridge of high pressure north of the Arctic Coast will persist
into Tue and then weaken Wed. This is causing areas of stratus
and fog along the Arctic Coast from Barrow east. This is also
causing east winds that will increase Mon night and Tue.= as
fronts approach from the south.

An Arctic Front stretching from Eagle to Nome will move to Eagle
to the Bering Strait by 4am Mon, to Old Crow to Kotzebue by 4pm
Mon. along the Brooks Range crest by 4am Tue, and to Barter
Island to Point Lay by 4pm Tue, then persist into Wed. There are
east winds 15 kt along this front. This will cause winds to
increase to 20-30kt over the North Slope north of the front Mon
into Tue.

An occluded front in southeast Bering will move to the Yukon Delta
by 4am Mon, to Gambell to Shageluk by 4pm Mon, then dissipate
along a Wale to Denali line by 4am Tue. Rain and snow will occur
with this front with no snow accumulation below 2000 feet.

A strong low southwest of Shemya will move to the southcentral
Bering by 4pm Mon, to the central Bering as a 978 mb low by 4pm
Tue, and to near Gambell as a 990 mb low by 4pm Wed. A front
extending east from this low will move over the southeast Bering
Mon, to St Matthew Island to a frontal wave near the YK Delta by
4am Tue, and by 4pm Fri to a frontal wave in western Norton Sound
with the front from the Bering Strait to Kotzebue to McGrath.
Frontal will move to Gambell to Point Hope to Atigun Pass to
Northway by 4am Wed, and to Provideniya to Barrow to Barter Island
by 4pm Wed. Expect rain and snow along the front, with no
accumulation below 3000 ft south of the Brooks Range. Could see 4
inches of snow above 3000 feet in some locations.
Could see several inches of snow with the front over the Eastern
North Slope, with freezing rain possible along the coast.

Expect south winds increasing to 50kt across the Alaska Range Tue,
and south to 30 kt over the Brooks range tue night into Wed. Winds
will decrease west of the front.

Another Wave is expected to move north over the YK delta Wed
bringing more rain/snow and winds.

&&

.DISCUSSION...
Models initialize well at the surface and aloft. Similar
solutions are shown through 4pm Mon, then the ECMF takes the
short wave energy further northeast than the GFS and NAM. Since
there is a strong jet streak moving northeast over SW Alaska Mon
night and over the Interior Tue, and North Slope Wed, this favors
the ECMF solution of moving the front and weather northeast
faster than the GFS/NAM for Tue into Wed.

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

&&

.FIRE WEATHER...
Strong Chinook winds along Alaska Range Tue.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
High Wind Watch for AKZ223.

High Wind Warning for AKZ225-AKZ226.

Small Craft Advisory for PKZ200-PKZ225-PKZ230.

Heavy Freezing Spray Warning for PKZ210.

Brisk Wind Advisory for PKZ235-PKZ240-PKZ245.

Gale Warning for PKZ210.
&&

JB APR 18