Small Craft Advisory 4, NWS Fairbanks, AK

359 
FZAK52 PAFG 121231
CWFWCZ

COASTAL WATERS FORECAST FOR NORTHWEST ALASKA
NATIONAL WEATHER SERVICE FAIRBANKS AK
331 AM AKST THU JAN 12 2017

NORTHWESTERN ALASKA COASTAL WATERS OUT 100 NM

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT THE AVERAGE OF THE HIGHEST ONE-
THIRD OF THE COMBINED WIND WAVE AND SWELL HEIGHT.

PKZ299-130300-
331 AM AKST THU JAN 12 2017

.SYNOPSIS FOR NORTHWEST COAST...
A RIDGE OVER SIBERIA WILL CONTINUE BUILD EAST OVER THE BERING 
STRAIT AND EASTERN BERING SEA THROUGH THURSDAY. A 975 MB LOW 
WILL MOVE TO THE NORTHERN GULF OF ALASKA BY FRIDAY MORNING. THIS
WILL INCREASE THE SURFACE PRESSURE GRADIENT OVER THE BERING 
STRAIT AND BERING SEA FRIDAY.

$$

PKZ200-130300-
NORTON SOUND-
331 AM AKST THU JAN 12 2017

.TODAY...N WINDS 15 KT. 
.TONIGHT...N WINDS 15 KT. 
.FRI...N WINDS 20 KT. BLOWING SNOW. 
.FRI NIGHT...N WINDS 20 KT. BLOWING SNOW. VSBY 1 NM OR LESS. 
.SAT...N WINDS 20 KT. 
.SAT NIGHT...N WINDS 15 KT. 
.SUN...N WINDS 15 KT. 
.MON...N WINDS 10 KT.  

$$

PKZ210-130300-
DALL POINT TO WALES-
331 AM AKST THU JAN 12 2017

...HEAVY FREEZING SPRAY WARNING IN EFFECT THROUGH LATE THIS
AFTERNOON...
...GALE WARNING IN EFFECT FROM LATE THIS AFTERNOON THROUGH EARLY
FRIDAY MORNING...

.TODAY...N WINDS 25 KT. SEAS 6 FT. FREEZING FOG. SNOW. HEAVY
FREEZING SPRAY. 
.TONIGHT...N WINDS 35 KT. SEAS 9 FT. FREEZING FOG. SNOW. HEAVY 
FREEZING SPRAY. 
.FRI...N WINDS 35 KT. SEAS 11 FT. FREEZING FOG AND BLOWING SNOW.
VSBY 1 NM OR LESS. HEAVY FREEZING SPRAY. 
.FRI NIGHT...N WINDS 35 KT. SEAS 12 FT. FREEZING FOG AND BLOWING
SNOW. VSBY 1 NM OR LESS. HEAVY FREEZING SPRAY. 
.SAT...N WINDS 35 KT. SEAS 12 FT. FREEZING FOG AND BLOWING SNOW.
VSBY 1 NM OR LESS. HEAVY FREEZING SPRAY. 
.SAT NIGHT...N WINDS 35 KT. SEAS 11 FT. FREEZING FOG AND BLOWING
SNOW. VSBY 1 NM OR LESS. HEAVY FREEZING SPRAY. 
.SUN...N WINDS 30 KT. SEAS 10 FT. 
.MON...N WINDS 25 KT. SEAS 7 FT.  

$$

PKZ215-130300-
KOTZEBUE SOUND-
331 AM AKST THU JAN 12 2017

.TODAY...NW WINDS 20 KT. 
.TONIGHT...NW WINDS 15 KT. 
.FRI...N WINDS 15 KT. 
.FRI NIGHT...N WINDS 20 KT. 
.SAT...N WINDS 20 KT. BLOWING SNOW. VSBY 1 NM OR LESS. 
.SAT NIGHT...N WINDS 20 KT. BLOWING SNOW. VSBY 1 NM OR LESS. 
.SUN...N WINDS 15 KT. 
.MON...N WINDS 10 KT.  

$$

PKZ220-130300-
WALES TO CAPE THOMPSON-
331 AM AKST THU JAN 12 2017

...BRISK WIND ADVISORY IN EFFECT THROUGH EARLY FRIDAY MORNING...

.TODAY...NW WINDS 25 KT. BLOWING SNOW. SNOW. VSBY 1 NM OR LESS. 
.TONIGHT...N WINDS 25 KT. BLOWING SNOW. SNOW. VSBY 1 NM OR LESS. 
.FRI...N WINDS 30 KT. BLOWING SNOW. VSBY 1 NM OR LESS. 
.FRI NIGHT...N WINDS 30 KT. BLOWING SNOW. VSBY 1 NM OR LESS. 
.SAT...N WINDS 30 KT. BLOWING SNOW. VSBY 1 NM OR LESS. 
.SAT NIGHT...N WINDS 30 KT. BLOWING SNOW. VSBY 1 NM OR LESS. 
.SUN...N WINDS 30 KT. 
.MON...N WINDS 25 KT.  

$$

JAN 17

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
336 PM AKST Wed Jan 11 2017

.DISCUSSION...

The main forecast challenge for Northern Alaska will be
temperatures from Friday onward into the extended forecast period
as colder, arctic air surges south. The 11/12Z GFS has changed its
tune regarding the degree of cold, warming up considerably at H850
over the Eastern Interior Monday and Tuesday when compared to the
12Z ECWMF which remain consistent in painting the coldest...-30C
H850 temperatures for late Monday into Tuesday. There is decent
agreement amongst the 11/12Z deterministic models through 00Z
Sunday. Thereafter, model solutions differ with the 11/12Z GFS
building a weak upper level ridge over the Eastern Interior
resulting in warmer temperatures than what was previously
advertised. The 11/12Z ECWMF remains consistent, but will see if
the details change in regards to Monday/Tuesday with the 12/00Z
run.

Several shortwaves are expected to move south over through
Thursday...helping to deepen and reinforce a longwave trough that
continues to dig south over Northern Alaska. By Friday, this
longwave trough will be oriented from the southwest over the
southern Bering to NW over the eastern Arctic Coast with a closed
low center over the lower to middle Yukon Valley. Cyclonic flow
aloft will persist through Saturday as the low center remains over
the western interior. However, by Saturday night the 11/12Z GFS
has the aforementioned low center and trough weaken as a weak
upper level ridge builds north...setting up warmer, return flow
over the eastern interior through Monday. The 11/12Z ECWMF is not
as aggressive with the ridge, keeping a weakened longwave trough
over Northern Alaska. By Monday afternoon, a shortwave lifts
northeast and over eastern interior through Tuesday. The GFS then
once against builds a weak upper level ridge setting up warmer,
return flow again over the eastern interior...while the ECWMF
deepens the trough. The resultant weather synoptic pattern will
have a huge impact regarding H850 temperatures. The 11/12Z GFS has
warmed up considerably with its recent run at H850, while the
ECWMF remains cold. At the surface, strong northerly flow will
develop over the Chukchi Sea...Bering Strait and Northern Bering
Sea as the pressure gradient tightens over those areas through the
weekend.

Arctic Coast and North Slope...Ongoing winter weather advisory for
Kaktovik and Barter Island will continue with the expectation
that another round of strong east winds will develop late this
evening and into the overnight...allowing for reductions in
visibility in blowing snow to ramp up again. Accumulating snow of
around an inch is expected east of Deadhorse with flurries
expected through Friday along the rest of the North Slope. Next
best chance for accumulating snow will come Saturday as a
weakening front lifts north from the eastern interior.
Temperatures are expected to cool off considerably from west to
east as winds decrease to 15 to 35 below...coldest along the
valleys north of the Brooks Range.

Western Interior and West Coast...Cold, northerly flow will
continue to develop over the West Coast through the weekend. Open,
relatively warm waters north of Saint Lawrence Island up through
the Bering Strait will be conducive to ocean-effect snow showers
through weekend or until the northern Bering Sea becomes ice-
covered. May see a few inches of snow through the weekend along
the Bering Strait and Saint Lawrence Island. North to Northeast
forecast winds up to 35 mph sustained and gusts to 50 mph are
favorable for high surf conditions for Savoonga and Gambell and
possibly Little Diomede Friday through Saturday. Still a bit
of uncertainty, so will only issue a SPS highlighting the
possibility. Also, there may be ice accretion due to freezing
spray in Savoonga that will also be highlighted in the SPS.

Eastern and Central Interior...So the great expectation of very
cold temperatures... 40 to 50 below...the coldest in a few
years...is looking less and less likely. Over the last 24 hours,
the GFS has warmed considerably...especially for what was going
to be the coldest day...and now is advertising for a low-end snow
event for the Eastern Interior. Will have to see what the ECWMF
does with its 00Z run this evening and 12Z run tomorrow morning.
At this time...both the NAM and ECWMF are still indicating for
H850 temperatures around -30C over the eastern Interior Saturday
night through Tuesday morning. Cyclonic flow with a moist 1000-700
mb layer will keep extensive cloud cover over the area through
early next week...per the GFS...with possible breaks Sunday
morning. The GFS, ECWMF, and NAME are all showing a warm, southeasterly
return flow developing late Friday into Saturday...which will
bring in a possibility of some accumulating snow to the eastern
interior and warm up the H850 temperatures a few degrees. Monday
morning through Tuesday...the 11/12Z GFS is advertising another
round of light snow...but for the eastern and central
interior...heaviest over the eastern interior. Will have to see
how this unfolds over the next few days.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory for AKZ204.

Heavy Freezing Spray Warning for PKZ210.

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

LTH JAN 17

Special Weather Statement
National Weather Service Fairbanks AK
306 PM AKST Wed Jan 11 2017

AKZ213-130000-
St Lawrence Island and Bering Strait Coast-
Including Gambell, Savoonga, Brevig Mission, Teller, Wales,
and Diomede
306 PM AKST Wed Jan 11 2017

...High Surf possible for Saint Lawrence Island and Bering Strait
late this week into the weekend...

Strong northerly winds are expected to develop over the Bering
Strait and Saint Lawrence Island Friday and persist through
Saturday. Strong northerly winds combined with a long fetch of
open water along and to the north of Saint Lawrence Island will
likely result in high surf at Gambell...Savoonga and Little
Diomede late Friday night into Saturday. High surf will be the
worst as north winds peak Saturday morning with gusts up to 50 mph
possible.

In addition to high surf, cold temperatures combined with a long
fetch of open water will be favorable for freezing spray to
develop and be blown into Savoonga. Ice accretion due to freezing
spray on electrical lines and equipment may cause power outages.

Some uncertainity in the amount of freezing spray remains as sea
ice extent may expand south of the Bering Strait due to colder
temperatures over the next few days. Sea ice growth north of
Saint Lawrence Island may reduce the likelihood of high surf.

For the latest forecast go to weather.gov/fairbanks.