Small Craft Advisory 225, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
1259 PM AKST Tue Nov 28 2017

.DISCUSSION...

Models...The 28/12Z solutions did initialize well against the
28/18Z surface analysis for positions and central pressures.Good
agreement aloft in the short term for this set of solutions.
Moving into the extended periods there continues to be some
similarity in the solutions early, then significant differences
the further out they go. Will use an equal blend for the short
term, but will need to go in an tweak the temperatures
individually. For the extended periods will lean on the WPC
solutions which used primarily a blend of the Ensemble means.

Aloft...at 500 hpa...Ridging extends south over the Arctic Coast
from a 545 dam high over the Pole and will slide west to the
Dateline by Wednesday morning as a 503 dam low develops south of
Banks Island and moves west over Prudhoe Bay by Wednesday morning.
The low will continue west to the Chukchi Sea by Wednesday night
at 506 dam, then southwest over the Bering Strait by Thursday
morning. A 510 dam low over the Central Brooks Range will move
southwest over Kotzebue by Wednesday morning, then merge with the
low moving over the Bering Strait. A weak trough will persist over
the Arctic Plain. Weak ridging over the Southeast Interior will
slide north a bit and push into the Central Interior east of
Tanana tonight an persist into Wednesday night before breaking
down. A 491 dam low near Cold Bay will weaken to 505 dam as it
moves over Sand Point by Wednesday evening, then moves south of
the Gulf of Alaska as it continues to weaken. Ridging over the
Western Bering Sea will move to the Eastern Bering Sea and Bering
Strait by Thursday evening. A col will develop over the Central
Interior Thursday and be pushed out by Friday morning as the
ridging over the West Coast moves inland. At 850
hpa...Temperatures over the forecast area will remain fairly
static from -5C to -15C as the -10 isotherm lies from Norton
Sound to Eagle through Thursday.

Surface...Ridging continues over the Central and Eastern Interior
with a 1005 mb high over the Yukon Territory and a 1002 mb high
over the Upper Yukon Flats. A 953 mb stacked low over Dutch Harbor
will slowly move to Sand Point by Wednesday evening, then moves
southeast into the north Pacific as it weakens. A ridge of high
pressure will push north over the western Bering Sea Wednesday
evening, and moves to the Eastern Bering Sea south of the Bering
Strait by Thursday morning. A weak high pressure pattern will
persist over the interior through the week. A weather front will
move to the Western Bering Sea Thursday morning, and to the West
Coast and Bering Strait by Friday morning. High pressure over the
Arctic will persist as a 1028 mb high north of the Canadian
Archipelago moves southwest to the Dateline, then west into the
Siberian Arctic. A weak trough will persist over the Arctic Plain
extending east to a 997 mb low near Banks Island. Leeside
troughing north of the Alaska Range with enhanced pressure
gradient in the upper Tanana Valley and across the Alaska Range as
high pressure persists over the Copper River Basin and Yukon
Territory. The high breaks down a bit Thursday, but expect it to
return on Saturday.

Arctic Coast and Brooks Range...Stratus persisting over the area
can be seen on the SPoRT NPP VIIRS Nighttime Microphysics RGB
product at 28/1746Z. GOES MVFR Probability from 28/1845Z showing
most of the Chukchi Sea and Arctic Coast have high probability of
stratus. With weak troughing in the area expect the stratus to
continue to hang over the area with flurries and patchy fog. Winds
along the coast will be primarily northeast at 10 to 20 mph, while
inland winds will be southeast to southwest at 5 to 15 mph.
Temperatures falling slowly through the weekend.

West Coast and Western Interior...Some stratus floating around in
the Bering Strait, Norton Sound, the Lower Yukon Delta, and the
Eastern Bering Sea may produce some light snow of flurries, up to
1 inch of snow can be expected on St Lawrence Island, elsewhere
no significant accumulations is expected tonight. Winds on the
coast northwest to northeast and generally decreasing overnight
south of Kivalina. North of Kivalina winds increasing with gusts
around 50 mph. Winds on St Lawrence Island and the Lower Yukon
Delta will be northeast to east at 15 to 30 mph. Temperatures
steady to slightly warmer as some warm air is pushed north.

Central and Eastern Interior...High pressure over the Yukon
continues to hold on impacting the weather in the Central and
Eastern Interior. Tanana Valley Jet will persist and increase some
overnight as the gradient tightens up a bit so expect gusts to 45
mph developing. Gap flow winds will develop across the Alaska
Range as well with some gust to around 40 mph tonight and
Wednesday, then gusts around 50 mph Wednesday night. A bubble high
develops north of the Ray Mountains, so expect some gusty winds
along the Elliott Highway to 45 mph tonight, strongest through
Ptarmigan Pass. With the exception of some high clouds moving
through the area, most areas will be partly cloudy the next couple
days. Not much snow in the forecast at this time, next chance
looks like Thursday for the Fairbanks area.

&&

Coastal Hazard Potential Days 3 and 4...Strong southeast to south
winds developing in advance of a storm in the Bering Sea has the
potential to produce High Surf on St Lawrence Island and in Norton
Sound Thursday night through Friday.

&&

Extended Forecast days 4 to 7...Relatively quiet in the Arctic and
over the West Coast. A weather front will move over the West Coast
Friday night and dissipate as it moves inland Saturday and Sunday.
Strong gusty winds will develop over the West Coast and Chukchi
Sea Saturday and persist into Monday.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Advisory for AKZ219-AKZ221.

Heavy Freezing Spray Warning for PKZ200-PKZ210-PKZ220-PKZ225-
PKZ230.

Small Craft Advisory for PKZ200-PKZ210-PKZ230.

Gale Warning for PKZ220-PKZ225.

Brisk Wind Advisory for PKZ235.

&&

SDB NOV 17