Gale Warning 138, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
355 AM AKDT Tue Oct 29 2019

.DISCUSSION...

Synopsis...A cold front developing off the West Coast will move
inland tonight as the anchor low in the Southwest Arctic moves
east. The front will move across the Western Interior with cold
air moving in with it. Temperatures will be cooling rapidly across
much of the area today with rain changing over to snow along and
behind the cold front. The front will continue east across the
Central and Eastern Interior, and Eastern Arctic Wednesday.
Heaviest snowfall will be in the the Brooks Range.

Models...29/00Z solutions are in good agreement in the short
term, but start to diverge beyond 60 hours, mainly with location
of the major features. Surface solution initialized very good with
location and strength of features spot on. NAM and GFS solutions
handling the tight pressure gradient north of the Alaska Range
well. The NAM is bringing the surface low closer to the coast as
it moves east, this will bring slightly stronger winds along the
coast so will lean toward it to start the short term. No
significant differences in the precipitation solutions.

Aloft...At 500 hpa...Long wave trough to the west is anchored by
a 529 dam low near Nunivak Island and a 516 dam low near Wrangel
Island. Ridging to the east extends northeast over the Southeast
Panhandle and Banks Island. The riding will weaken allowing the
trough to slide east to lie over the West Coast later this morning
as the low moves over the Central Chukchi Sea as it weakens to
512 dam. By Wednesday morning the low will be just north of
Wainwright at 514 dam with the trough extending south over Galena
and McGrath. By Thursday morning flow over the state will become
zonal as the trough moves over the Northwest Territories, while
the low will move to 100 nm north of Nuiqsut at 518 dam. A branch
of the Pacific ridge will rotate over the Alaska Peninsula and
Eastern Bering Sea Wednesday, and over the southeast mainland by
Thursday morning. At 850 hpa...Dome of warm air with temperatures
near +10C that was over the state Monday is moving east and
moderating with some remnants above +0C hanging over the Eastern
Arctic Coast and the Southeast Interior. The -10C isotherm is
wrapping in behind the low that is moving over the Chukchi Sea and
is moving over the Northwest Arctic Coast, Chukchi Sea Coast, and
Bering Strait today. By Wednesday morning -10C isotherm will push
southeast to lie from Point Barrow to Huslia to Kaltag to Scammon
Bay to Gambell by Wednesday morning.

Surface...Weak high pressure is pushing in over the Southeast
Interior and will hold on while it continues to weaken. Leeside
troughing north of the Alaska Range is creating a tight pressure
gradient across the range today with strong gusty winds near
passes persisting, the gradient will relax late this afternoon and
evening. A 993 mb low is near MacKenzie Bay, with a 978 mb low
150 nm northwest of Point Lay, a 1000 mb low in Norton Sound, and
a 997 mb low near Nunivak Island. The lows on the West Coast will
weaken as they move inland and merge into the cold front that will
lie from Deadhorse to Bettles to McGrath, while the low near
Point Lay moves to 100 nm northwest of Wainwright by Wednesday
morning. The low near MacKenzie Bay will move east into the
Canadian Archipelago. The Cold Front will move east of the AlCan
by Wednesday evening and high pressure will push in between the
ranges as a 1022 mb high moves over the Lower Yukon Delta, and a
1024 mb high moves over St Matthew Island by Wednesday afternoon.
By Thursday morning the low in the Arctic will be 150 nm north of
Nuiqsut, a band of high pressure will be between the ranges with a
1025 mb high near Fairbanks, and a 988 mb low will move out of
the Central Pacific to 250 nm south of Dutch Harbor.

Arctic Coast and Brooks Range...Front will be moving east across
the area with rain changing to snow today as cold air wraps in
around the low off the Northwest Coast over the area. High Surf
will continue around Utqiagvik as strong gusty winds associated
with the low persist over the Southwest Arctic. Coastal surge of
around 2 feet is expect and will combine with elevated wave
action to produce erosion problems. Winds will be west to
northwest over most of the area with the strongest winds on the
Northwest Coast as winds increase today to 30 to 40 mph gusting to
55 mph. Winds in the Central Arctic Coast will be 15 to 25 mph
gusting to 40 mph, with lighter winds to the east. Winds will
increase along the coast as the low moves east. Temperatures will
be cooling behind the front.

West Coast and Western Interior...Cold front is developing over the
coast and will move inland today with cooler temperatures and
clearing skies behind it. A mix of rain and snow this morning will
change to snow late this morning as the cooler air pulls in behind
the front. Winds generally light will become northwest to north
at 5 to 15 mph.

Central and Eastern Interior...Some heavy snow along the south
slopes of the Brooks Range today and tonight once the rain changes
back to snow. Locally up to 10 inches of snow is possible north of
Bettles. Some snow will also fall on summits across the interior
with up to 4 inches of accumulation. Strong gusty gap winds near
the Alaska Range passes to around 55 mph today will diminish in
the evening. A cold front will be moving east across the Interior
Wednesday with with snow over most of the area with 1 to 3 inches
of accumulation.

&&

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

&&

Extended forecast for days 4 to 7...A low pressure system will
move to Bristol Bay, then weaken and the associated weather front
will move into the Interior spreading snow to areas mainly south
of the Yukon River through Sunday morning. A trough of low
pressure will remain over the Arctic with a weak front hanging
over the Arctic Coast bringing periods of snow to the area. A low
will move northeast across the Gulf of Alaska Sunday and will spin
some snow over the Eastern Interior Sunday night and Monday.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Advisory for AKZ223-AKZ226.

High Surf Advisory for AKZ202.

Winter Weather Advisory for AKZ217-AKZ218.

Small Craft Advisory for PKZ210-PKZ215.

Gale Warning for PKZ220-PKZ225-PKZ230-PKZ235.

&&

SDB OCT 19