Small Craft Advisory 232, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
155 PM AKST Tue Dec 4 2018

.DISCUSSION...
Active weather continues over the West Coast and Western Interior
with snow, blowing snow, freezing rain and strong winds while
strong winds continue to blast the Alaska Range Passes and
foothills.

Models...the 12z model suite initialized well against the 12z
surface analysis and verified well against the 18z surface
analysis. Model spread on the 12z run is reasonable into late
week and displays considerable improvement over the last several
model runs.

Aloft at 500 hp, a 510 DAM low currently located over the central
Aleutian Islands anchors a deep longwave trough over the central
and western Bering Sea. The longwave trough will deepen and drift
to the east through the end of the week and will be located along
the West Coast of Alaska Friday. A series of shortwave troughs
will rotate around the longwave trough moving north over the West
Coast and Western Interior through the end of the week as an upper
level ridge centered over the Yukon holds fast through the week.
A 480 DAM low moves south along 140W and will be located just
northwest of Banks Island by Friday. A strong trough moves south
out of the high Arctic over the North Slope by Friday and will
usher in a colder airmass over most of northern Alaska early next
week.

On the surface, a 972 mb low currently located over the central
Aleutians will continue to drift slowly to the east as a strong
occluded front currently located over the lower YK Delta moves
north and east over the Seward Peninsula and western interior this
evening. The front will slow down and weaken as it moves northwest
into the Bering Strait tonight and will be the focus for periods
of snow and strong winds over much the lower YK Delta, Norton
Sound Coast, the Seward Peninsula, the Bering Strait and St
Lawrence Island. Winter Weather Advisories have been issued for
these areas for snow and blowing snow. A Winter Storm Warning has
been issued for zone 213 where warning level wind gusts are
expected on St Lawrence Island and through the Bering Strait in
addition to low visibilities in snow and blowing snow.

A second low develops along the triple point of the Aleutian Low
over Bristol Bay Wednesday morning and will move north over the
lower YK Delta as a 999 mb low Wednesday evening. This low
continues to deepen to around 994 mbs and stalls over Norton
Sound on Thursday. Abundant moisture combined with enhanced
upslope wind direction over the southern portions of the Seward
Peninsula has the potential to produce heavy snow Wednesday night
and Thursday. A Winter Storm Watch has been issued for these areas
for heavy snow and blowing snow especially over the western
Seward Peninsula. Snowfall develops over the Western Interior
Wednesday night and moves north with heavier snow developing over
the southern faces of the western Brooks Range by Thursday
morning.

Southerly winds aloft will continue to produce weak mountain wave
over the Alaska Range and will produce gusty winds through the
Alaska Range Passes and along the northern foothills. Winds are
not expected to reach warning levels but will reach advisory
criteria off and on through the end of the week as shortwaves pass
over the Alaska Range.

Strong northerly winds will continue through the Bering Strait and
over St Lawrence Island through Friday. Storm surge guidance
continue to indicate elevated water levels along the north shores
of St Lawrence Island developing on Friday and continuing into
Saturday. Continue to monitor.

Coastal Hazard Potential Days 3 and 4...Strong northerly winds will
continue through the Bering Strait and over St Lawrence Island
through Friday. Storm surge guidance continue to indicate elevated
water levels along the north shores of St Lawrence Island
developing on Friday and continuing into Saturday. Continue to
monitor.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Wind Advisory for AKZ225-AKZ226.

Winter Storm Watch for AKZ211-AKZ210.

Winter Storm Warning for AKZ213.

Winter Weather Advisory for AKZ211-AKZ212-AKZ214-AKZ215.

Heavy Freezing Spray Warning for PKZ210-PKZ220-PKZ225-PKZ230.

Small Craft Advisory for PKZ200-PKZ220-PKZ225.

Gale Warning for PKZ210.
&&

CCC DEC 18