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Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
241 PM akst Sat Nov 18 2017

Discussion...
very active weather pattern continues to hammer western Alaska.

Ongoing blizzard on the West Coast continues to intensify this
evening with many locations already reporting blizzard conditions
along the West Coast from Nome south and heavy snow and or
freezing rain in the yk Delta and on St Lawrence Island and the
Bering Strait.

Aloft at 500 hpa, a strong shortwave over the chukotsk peninsula
continues to push east and south flattening the upper level ridge
over the southeastern Bering Sea. As the ridge continues to get
squeezed south and west the shortwave will continue to dig south
and east and strengthen the longwave that is currently over
eastern Alaska and the Yukon and is slowly moving to the west.
Cold airmass over the Yukon and eastern interior brought the first
minus 20 day to Fairbanks and many areas of eastern Alaska.
Mostly clear skies over the central and eastern Alaska will
promote another cold night with temperatures in the teens and 20s
as well as a few 30s below in coldest locations. 40 below not out
of the question for the Yukon Flats and coldest spots in the
fortymile country Monday night. A Tanana Valley jet will develop
this evening and will produce gusty southeast winds from Delta
Junction west to include Salcha and Nenana. Expect easterly winds
gusting to around 40 mph in Delta Junction area tonight and
Sunday morning and wind gusts to 25 mph in Salcha and Nenana.

On the surface a 988 mb low currently over the Gulf of Anadyr
moves rapidly south and east as the associated front currently
extending south and east from the low to St Lawrence Island to the
yk Delta rapidly occludes and remains the Focal Point for heavy
snow. The low continues to deepen to 984 mb as it moves into
Norton Sound tonight and moves over Kodiak Island as a 982 mb low
Sunday morning. An inverted trough will remain over the West Coast
and will continue to produce snow through early afternoon over the
West Coast. Storm total snow is expected to between 4 and 12
inches with locally higher amounts from the Bering Strait
southeast to McGrath. Freezing rain and rain freezing on the
ground and Road surfaces is expected to produce up to one half
inch of ice accumulation south and west of Anvik.

West winds will increase tonight as the low passes to the south
and will produce a 3 to 4 foot storm surge along the Norton Sound
coast south of Stebbins and along the yk Delta coast. The surge
will back up the Yukon river several miles producing elevated
water levels. Water levels will relax Monday as winds decrease.

A second strong low will move from the western Bering into the
Gulf of Anadyr on Monday and over the southern Chukchi Sea Tue.
This will bring another round of strong winds, snow, blowing snow
and possible blizzard conditions to the West Coast late Monday
night and Tuesday. This could bring a significant storm surge and
possible coastal flooding to the West Coast of Alaska Tue into
Wed, but still much uncertainty on this. Will keep eye on this
feature for further developments.

A third very strong low will move into the central Bering Sea
Thursday and Friday. Model guidance continues to indicate surface
pressures dropping to below 960 mbs with considerable spread on
the track of the storm. This storm has the potential to bring yet
another round of significant storm surge and possible coastal
flooding to the West Coast of Alaska in addition to strong winds,
heavy snow and freezing rain. Continue to monitor.



Coastal hazard potential days 3 and 4...
a second strong low will move from the western Bering to near
Anadyr on Mon and over the southern Chukchi Sea Tue. This will
bring another round of strong winds, snow, blowing snow and
possible blizzard conditions to the West Coast Mon night and Tue.
This could bring a significant storm surge and possible coastal
flooding to the West Coast of Alaska Tue into Wed, but still much
uncertainty on this. Will keep eye on this feature for further
developments.

A third very strong low will move into the central Bering Sea
Thursday and Friday. Model guidance continues to indicate surface
pressures dropping to below 960 pbs with considerable spread on
the track of the storm. This storm has the potential to bring yet
another round of significant storm surge and possible coastal
flooding to the West Coast of Alaska in addition to strong winds,
heavy snow and freezing rain. There is considerable model spread
on the track and strength of this storm as well. Continue to
monitor.

&&

Afg watches/warnings/advisories...
high surf advisory for akz212-akz214.

Winter Storm Warning for akz214-akz215-akz216.

Blizzard Warning for akz207-akz209-akz210-akz211-akz212-akz213.

Winter Weather Advisory for akz208.

Heavy freezing spray warning for pkz200-pkz210-pkz215-pkz220-
pkz225-pkz230-pkz235.

Gale Warning for pkz200-pkz215-pkz220-pkz225-pkz230.

Storm Warning for pkz210.

Small Craft Advisory for pkz235.

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