High Surf Advisory 12, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
514 AM AKST Fri Nov 30 2018

.DISCUSSION...

Synopsis...A busy end to the week is expected for much of the
west coast and western Interior. A series of lows will track
northward up the west coast of Alaska, with bringing heavy snow
and ice, gusty winds, near blizzard conditions, and coastal
impacts.

Aloft 500 mb...
A 492 dam low east of Kamchatka lies near the center of a broad
longwave trough spanning much of eastern Siberia into the central
Bering Sea. The low will remain in place through the weekend as it
spawns a series of shortwaves along its southeastern periphery
over the Aleutians. These waves will sweep northward along the
west coast and into the Chukchi Sea by late Saturday. Ridging
will build over Eastern Alaska Friday afternoon into Saturday
before shifting to the east over Canada as shortwaves begin to
erode the ridge over the Interior on Sunday. Ridging will build
back in over the state early next week.

Models...
The ECMWF remains an outlier with regards to strength and track
of the low, particularly as it transits the Chukchi Sea early
Sunday, the GFS and NAM have been more consistent with the track
of the low pressure centers, so we are sticking with the GFS
with this forecast package. Aloft models begin to diverge by early
next week with the placement of an upper level low over the
Aleutians.

North Slope and Brooks Range...
A strong front associated with a deep cyclone in the Bering Sea
will impact the central and eastern Brooks Range early Saturday,
and reach the North Slope by Saturday evening. Strong easterly
winds and moderate snowfall is expected along the front mainly
west of Utqiagvik. A tight pressure gradient will set up along
the Brooks range Saturday afternoon into Sunday. Winter storm
watches have been issued for the potential for strong winds with
blowing snow and low visibility in the passes.

West Coast and Western Interior...
A frontal boundary is currently moving into the Bering strait and
across the Yukon Delta this morning. Snowfall of 2 to 4 inches is
expected for most areas with the initial wave. A second low will
deepen to 977 mb over the southern Bering Sea late Friday into
Saturday as it swings a second front northward across the Y-K
Delta and into the Norton Sound and Western Interior. This will be
the more impactful event, as deep saturation combined with warm
advection will create a multitude of hazards ranging from mixed
precipitation and ice for the coast south of the Bering Strait and
lower Yukon and Kuskokwim Valleys, to heavy snow along the higher
terrain of the Nulato hills and areas farther north to the
southern Brooks Range. Winter Storm Watches have been upgraded to
warnings for zones 208-209, 210 216 and 217. Snow accumulations
around 4 to 8 inches with heavier amounts in the Nulato hills and
upslope areas of the Upper Kobuk and Noatak valleys. A coastal
flood watch has been issued for zone 211. Strong southeast winds
early saturday will switch to a more southwesterly direction
which could bring high water to flood prone areas of Nome such as
Belmont Point and along the Nome-Council road. Coastal flooding
may affect structures in Golovin as well. Storm surge guidance
is showing the surge to be 4 to 6 feet above the normal highest
tide line. Water levels will begin to rise early Saturday and will
remain high into Sunday. This is a fast moving system and the
duration is not that long which may limit the flood potential. The
watch is from Saturday morning through Sunday afternoon. Another
low will follow on Sunday bringing more snow and wind to the west
coast. Precipitation will begin to taper off on Monday.

Central and Eastern Interior...
Scattered snow showers and clouds will persist through early
Friday for the Eastern interior this morning. As the Bering low
move north across the coast will swing a powerful shortwave north,
bringing snow to portions of the central and northern Interior
and forcing a tightening of the pressure gradient across the
Alaska Range. High wind watches have been upgraded to warnings for
the Alaska range passes. Gusts to 70 mph are expected on
Saturday. Winds will diminish some late Saturday night. Winter
weather advisories have been issued for zones 221 219 and 218 for
4 to 7 inches of snow. Areas of blowing snow and low visibility
are possible over higher terrain and along the Dalton Highway. For
zone 221 snow mainly from Manley hot springs west. As an upper
level shortwave slides to the east there is a potential for 1 to
2 inches of snow for the Middle Tanana valley late Saturday night
into Sunday morning. Another wave could bring more snow Monday
morning into Monday afternoon for the Central and Southern
Interiors.

Coastal Hazard Potential Days 3 and 4...
A deep low will move north through the eastern Bering Sea
beginning late Friday before entering the Chukchi Sea by Sunday.
This system has the potential to bring elevated water levels to
the west coast as well as Bering Sea islands. Strong southeast winds
early saturday will switch to a more southwesterly direction which
could bring high water to flood prone areas of Nome such as
Belmont Point and along the Nome-Council road. Coastal flooding
may affect structures in Golovin as well. The watch is from
Saturday morning through Sunday afternoon.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory for AKZ207-AKZ211-AKZ212-AKZ213-AKZ214-
AKZ215-AKZ218-AKZ219-AKZ221-AKZ227.

Winter Storm Warning for AKZ208-AKZ209-AKZ210-AKZ216-AKZ217.

Coastal Flood Watch for AKZ211.

High Wind Warning for AKZ225-AKZ226.

Winter Storm Watch for AKZ205-AKZ206.

Heavy Freezing Spray Warning for PKZ200-PKZ210-PKZ220-PKZ225.

Small Craft Advisory for PKZ200-PKZ210-PKZ220-PKZ225.

Brisk Wind Advisory for PKZ215-PKZ230-PKZ235-PKZ240.
&&

JK NOV 18