Scientific Forecaster Discussion
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Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
340 PM akst Mon Nov 20 2017
A long wave pattern consisting of a ridge over the Bering Sea and
West Coast of Alaska with a trough over northwest Canada and eastern
Alaska will persist through the week. A series of strong short
wave troughs will move through the ridge and into the West Coast
of Alaska every 2 days or so keeping the very stormy pattern
through the week. The West Coast and western interior and Arctic
can expect strong winds, heavy snow, possible blizzards and
the potential for some coastal flooding with each of these
storms. The eastern interior will remain cold through the week.
Aloft...at 500 hpa...a 505 dam low 400 nm north of Point Barrow
will split with a 503 dam low moving northwest to the dateline,
and a 502 dam low moving southeast into Canada Tuesday. A 510 dam
low south of the western Gulf of Alaska will move south with a
trough extending north to Yakutat persisting into Wednesday then
moving east. At 850 hpa...-20 isotherm lies along the crest of
the Alaska Range to Paxson then to Fort Yukon to Coldfoot to
Wainwright and will slowly move northeast. The -10 isotherm lies
from Valdez to Healy to Huslia to Point Hope.
Surface...high pressure S of the Bering Strait will move southeast.
A 986 mb low near the Kamchatka peninsula moves to the Gulf of
Anadyr this evening at 973 mb, and into the central Chukchi Sea by
Tue afternoon at 970 mb. The associated weather front will move
to St Lawrence Island this evening, and to the West Coast tonight,
then into Mainland Alaska. A tight pressure gradient around the
low will produce strong winds across the area Tue and Tue night.
Another 966 low will move into Bristol Bay on Wednesday. This
could bring more blizzard conditions for Saint Lawrence Island and
the Yukon Delta Wednesday afternoon into Thursday.
Arctic coast and Brooks range...blizzard conditions move east
Tuesday night and Wednesday morning into the Point Barrow area,
but do not work any further east at this time, but expect some
increased winds from Nuiqsut east with blowing snow. Winds speed
to the west will be 30 to 40 mph gusting to 55 mph west of
Nuiqsut, with winds 15 to 25 mph gusting to 40 mph from Nuiqsut
east. Brooks range passes will see increasing winds tonight with
the strongest winds west of Anaktuvuk Pass gusting to 50 mph,
while winds from Anaktuvuk Pass east will be gusting to around 35
mph. Snow will generally be light across the area, but the
incoming storm will bring some heavy snow to the western Brooks
range and parts of the Northwest Arctic coast with 4 to 8 inches
West Coast and western interior...snow will be moving to St
Lawrence Island by early afternoon and may mix with rain this
evening, then all snow overnight. Southerly winds increasing to
25 to 40 mph gusting to around 55 mph. Expect blizzard conditions
over a large portion of the West Coast through Tuesday night.
Another round of heavy snow in the Kobuk and Noatak valleys could
produce over a foot of snow in some locations with most areas
getting 5 to 8 inches.
Central and eastern interior...with the clear skies temperatures
will again bottom out with most areas 20 to 30 below Tuesday
morning. Around Fairbanks temperatures will be in the 15 to 25
below range. Temperatures warming when the clouds move in. Winds
will generally be light in the valleys, but gap winds in the
Alaska Range will kick up near passes around midnight gusting to
45 mph and diminish Tuesday afternoon. The Tanana Valley jet will
also kick in late this evening with winds around Delta Junction
gusting to around 30 mph from the east. The western interior
will see some snow move in Tuesday morning into Tuesday evening
before tapering off Wednesday morning. Snow accumulations around 2
inches are possible for the western interior. Snow may make it
into the middle Tanana Valley and drop 1 to 2 inches or so before
tapering off Wednesday morning.
Coastal hazard potential short term...
Coastal flood warnings issued for Norton Sound and and north
along the coast including Kivalina. Coastal flood advisories
issued for Kotzebue Sound and along the coast of the Yukon
Strong westerly flow will increase the surge at Kotzebue
approximately 5.5 ft Tuesday evening into Wednesday morning.
SW winds 30 to 40 mph may push new/Young ice onshore. Minor
flooding in low areas east of Kotzebue near dog yards and along
Unalakleet: total water approx 12 ft (surge 8 ft) peaking around
midnight Tuesday night. Possible inundation around fish processing
plant, boat launch and other low areas. Significant wave run-up
and erosion along the coastline expected.
St michaels: 11. 5 ft (surge 7.5 ft) peaking around 3am Wed
morning. Flooding of low lying areas possible.
Shishmaref: total water approx 5 ft (surge 4 ft) peaking aroudn 3
am Wed morning with high tide. Minor flooding of low lying areas.
Kivalina: 5 ft surge peaking around 3 am Wed morning with high
tide. SW winds 35 to 50 mph could push water into The Lagoon and
cause flooding on The Lagoon side of channel street. Significant
wave run-up and erosion along the coastline expected.
Golovin: total water approx 9 ft (surge 7 ft) peaking around
midnight Tue night to 3 am Wed morning. Old runway and areas just
east of the school in town could see flooding. Wind direction not
favorable to push water into the Bay.
Nome: total water approx 5 ft (surge 4 ft) peaking Tuesday night.
Winds from the west not favorable for flooding. Wave run-up and
erosion along the coastline possible.
coastal Flood Warning for akz207-akz211-akz212.
Coastal flood advisory for akz209-akz214.
Blizzard Warning for akz201-akz202-akz205-akz206-akz207-akz208-
Winter Weather Advisory for akz212-akz214.
Heavy freezing spray warning for pkz200-pkz210-pkz215-pkz220-
Gale Warning for pkz200-pkz210-pkz215-pkz220-pkz225-pkz230-
Brisk Wind Advisory for pkz240-pkz245.