Winter Storm Warning 10, NWS Fairbanks, AK

Northern Alaska Forecast Discussion...CORRECTED
National Weather Service Fairbanks AK
609 AM AKST Sun Feb 10 2019

.DISCUSSION...
The active weather pattern continues into midweek as a series of
fronts move across northern Alaska and a strong low moves north
across the Bering Sea.

Aloft, at 500 mb, a ridge axis is stretched along the Alcan
border, with a sharp shortwave stretching from the Gulf of Anadyr
across the central Bering Sea to just east of the Pribilofs to
Cold Bay. A closed high will briefly develop near Eagle by this
afternoon, with ridging remaining along the Alcan border, while
the shortwave moves east northeast to be stretched across the
Chukotsk Peninsula to Diomede to Kotlik to Russian Mission to a
low situations in the Gulf of Alaska southeast of Kodiak. The
closed high will weaken by Monday morning and be stretched from
Banks Island southwest to Dawson to McCarthy, while the shortwave
continues to track east northeast to be located from Wainwright to
Bettles to Tanana to Lake Minchumina to Anchorage. Behind the
shortwave, ridging once again begins to build in across the West
Coast, while yet another strong low moves into the western Bering
Sea. As this strong low in the western Bering Sea moves
northeastward Monday, the associated shortwave will slide across
the West Coast and Western Interior, pushing the ridge axis
eastward across the state.

Surface...A 998 mb low over the western Seward Peninsula this
morning will quickly move northeast to be a 997 mb low 100 NM
northwest of Wainwright by this afternoon, and a 994 mb low 350 NM
northeast of Utqiagvik by Monday morning. A front/surface trough
remains stretched along the West Coast this morning from Point
Hope to the Seward Peninsula to west of Nunivak Island. The
feature has been slow to move, but is anticipated to get pushed
eastward today across the Western Interior and western Arctic
Coast and the Central and Eastern Interior and eastern Arctic
Coast tonight into Monday.

A strong 960 mb low will move into the western Bering Sea tonight
weakening to 966 mb by Monday afternoon as it moves northeast to
be 150 NM southwest of St Lawrence Island. The low will continue
to weaken as it moves northeast Monday night to be a 978 mb low
near Kotzebue Sound by Tuesday morning and a 984 mb low located 75
NM north of Nuiqsut Tuesday afternoon. The low will send a front
northeast across the state Monday and Tuesday.

Models...00Z model suite initialized fairly well against the 00Z
RAOBS and 00Z and 06Z surface obs. All models appear to be
underestimating the strength of the ridge at 500 mb. Model
solutions are in good agreement with the overall synoptic pattern
through mid week. At the mesoscale level, models spread begins to
be more noticeable Monday with differences in the strength of the
strong low in the Bering Sea, with the GFS being the deepest, and
the NAM and ECWMF being similar in strength.

North Slope and Brooks Range: The pressure gradient has weakened
across the Brooks Range this morning with winds diminishing. South
to southwest winds with gusts to around 35 mph remain possible
near passes, but expect visibility to stay above half a mile. A
weather front along the West Coast will continue to bring heavy
snow to the south side of the western Brooks Range into tonight.
As the front pushes east across the Arctic Coast today and Monday,
it will bring periods of snow to the coast. The next system will
bring another round of heavy snowfall to the south side of the
Brooks Range. Winds will ramp up in the Brooks Range Monday night
and Tuesday, with south winds near passes gusting to 40 mph. The
winds combined with falling snow will likely result in
visibilities of half a mile or less and a winter weather advisory
will likely be needed for zone 206.

West Coast and Western Interior: The next weather front remains
draped along the West Coast this morning and has been slow to
move. The front is anticipated to move into the Western Interior
today, bringing another round of heavy snow, gusty winds, blowing
snow, as well as rain and mixed precipitation (primarily from the
Seward Peninsula and south). The heaviest snowfall is expected
from Kotzebue and Ambler north, where snowfall totals of 6 to 12
inches are generally expected. Additional snowfall of 4 to 7
inches include the Nulato Hills as well as the southern half of
the Seward Peninsula. A number of warnings and advisories remain
in effect. There will be a brief lull in activity tonight, before
the next system moves onshore the West Coast Monday. A strong low
will move northeast across the Bering Sea, accompanied by a front,
and will bring another round of heavy snow, blowing snow, and
mixed precipitation. Strong southeasterly winds on the back side
of the low will affect the Y-K Delta and the coast of Norton Sound
late Monday night into Tuesday. There are still some model
differences in the strength, exact track and timing of the low
that will affect exactly where and when the strongest winds are
expected. The winds on the back side of this system will likely
cause some coastal impacts that are detailed in the coastal
hazards section below.

Central and Eastern Interior...Fairly quiet conditions expected
today across the Central and Eastern Interior, with the area
largely precip free. Ahead of the front on the West Coast,
southerly gap winds have developed in the Alaska Range passes and
they will continue into late this afternoon. A Wind Advisory
remains in effect for zone 226. Winds have been stronger than
anticipated in zone 225 and will have to be monitored this
morning. The Tanana Valley Jet is blowing across zone 223 this
morning, with gusts to 45 mph. Expect winds to stay below advisory
criteria there. Snow chances return tonight and Monday with the
approach and passage of the next front. On the heels of that
front, another system will be moving east, continuing snow chances
across the Interior Monday night and Tuesday and bringing
increasing and gusty southwesterly winds to the region. The
heaviest snowfall is expected from the Dalton Highway and west in
zones 218 and 219. Have issued a Winter Storm Watch for these
locations for Monday afternoon through Tuesday afternoon for the
potential for 7 to 12 inches of snow. Another round of southerly
gap winds will develop in the Alaska Range passes Monday and
Tuesday.

Coastal Hazard Potential Days 3 and 4...A strong low moving north
through the Bering Sea will bring strong southwesterly winds to
the coast Monday night into Tuesday. Ice in Norton Sound will
prevent the development of large waves; however, this system will
still cause elevated water levels along the coast of Norton Sound,
especially from Unalakleet north (although exactly how high the
water will get is uncertain at the moment). The water may inundate
and pond on top of existing sea ice in Norton Sound and adjacent
bays. In addition, the winds may push some chunks of ice up onto
the beach in Norton Sound. We will continue to monitor this
system.

&&

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

Winter Weather Advisory for AKZ214.

Winter Storm Warning for AKZ207-AKZ208-AKZ209-AKZ210-AKZ211-
AKZ212-AKZ213-AKZ215-AKZ216-AKZ217.

Winter Storm Watch for AKZ218-AKZ219.

Gale Warning for PKZ210.

Brisk Wind Advisory for PKZ200-PKZ210-PKZ215-PKZ220-PKZ235-
PKZ240-PKZ240-PKZ245.
&&

FEB 19