Gale Warning 683, NWS Anchorage, AK

122 
FZAK62 PAFC 190036
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
336 PM AKST Mon Dec 18 2017

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-191415-
336 PM AKST Mon Dec 18 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 946 mb low at 59N 172E sweeps into the Chukchi Sea for Wed 
morning. The associated front moves into Mainland Alaska Tue 
morning. A pair of North Pacific lows merge near 53N 179E at 984 
mb Wed morning and shifts to 60N 176W at 969 mb Wed afternoon. Its
associated front moves to the Central Aleutians by Wed afternoon.

$$

PKZ411-191415-
Bering Sea Offshore West of 180 and East of the International
Dateline-
336 PM AKST Mon Dec 18 2017

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...SW wind 45 kt. Seas 28 to 35 ft. Snow showers.
.TUE...W wind 30 to 45 kt becoming SW 20 to 35 kt in the
afternoon. Seas 25 to 35 ft subsiding to 17 to 27 ft in the 
afternoon.
.TUE NIGHT...W wind 25 to 40 kt becoming NW 15 to 30 kt after
midnight. Seas 15 to 23 ft.  and rain showers.
.WED...NW wind 20 to 35 kt. Seas 11 to 19 ft.
.WED NIGHT...N wind 10 to 25 kt. Seas 9 to 14 ft.
.THU THROUGH SAT...NW wind 15 to 30 kt. Seas 8 to 16 ft.

$$

PKZ412-191415-
Bering Sea Offshore 171W to 180 and North of 56N-
336 PM AKST Mon Dec 18 2017

...STORM WARNING TUESDAY NIGHT...

.TONIGHT...SW wind 30 to 45 kt. Seas 22 to 32 ft. Snow showers.
.TUE...SW wind 35 to 45 kt. Seas 27 to 33 ft.
.TUE NIGHT...SW wind 35 to 50 kt. Seas 18 to 30 ft. Rain showers.
.WED...SW wind 45 to 60 kt. Seas 20 to 35 ft.
.WED NIGHT...W wind 10 to 25 kt. Seas 15 to 23 ft.
.THU...NE wind 25 to 40 kt. Seas 10 to 18 ft.
.FRI THROUGH SAT...NW wind 10 to 25 kt. Seas 11 to 19 ft.

$$

PKZ413-191415-
Bering Sea Offshore 171W to 180 and South of 56N-
336 PM AKST Mon Dec 18 2017

...STORM WARNING TUESDAY NIGHT...

.TONIGHT...SW wind 30 to 40 kt. Seas 19 to 29 ft. Snow showers.
.TUE...SW wind 40 kt. Seas 23 to 29 ft.
.TUE NIGHT...S wind 35 to 50 kt. Seas 22 to 30 ft.
.WED...SW wind 45 to 60 kt. Seas 16 to 31 ft.
.WED NIGHT...S wind 25 to 40 kt. Seas 13 to 21 ft.
.THU...N wind 25 to 40 kt. Seas 9 to 17 ft.
.FRI THROUGH SAT...NW wind 15 to 25 kt. Seas 9 to 17 ft.

$$

PKZ414-191415-
Bering Sea Offshore East of 171W-
336 PM AKST Mon Dec 18 2017

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...SW wind 25 to 40 kt. Seas 14 to 22 ft.
.TUE...SW wind 35 kt. Seas 15 to 25 ft.
.TUE NIGHT...SW wind 30 kt becoming 25 to 40 kt after midnight.
Seas
17 to 24 ft.
.WED...S wind 35 to 50 kt. Seas 16 to 28 ft.
.WED NIGHT...SE wind 30 to 45 kt. Seas 16 to 26 ft.
.THU...SE wind 20 to 35 kt. Seas 11 to 19 ft.
.FRI...S wind 15 to 30 kt. Seas 10 to 17 ft.
.SAT...E wind up to 15 kt. Seas 9 to 14 ft.

$$

606 
FZAK62 PAFC 191229
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
329 AM AKST Tue Dec 19 2017

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-200115-
329 AM AKST Tue Dec 19 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 986 mb low will move to 53N 169E this afternoon, then it will 
move to 56N 179W at 979 mb Wed morning, then to 62N 176W at 973 
mb Wed afternoon. A 991 mb low moves to 53N 171E at 991 mb Wed 
afternoon then it will move to 52N 177E at 994 mb Thu morning. 

$$

PKZ411-200115-
Bering Sea Offshore West of 180 and East of the International
Dateline-
329 AM AKST Tue Dec 19 2017

...GALE WARNING THROUGH TONIGHT...

.TODAY...W wind 30 to 45 kt becoming SW 20 to 35 kt in the
afternoon. Seas 24 to 32 ft subsiding to 17 to 27 ft in the
afternoon.
.TONIGHT...W wind 25 to 40 kt becoming NW 15 to 30 kt after
midnight. Seas 15 to 23 ft. Snow and rain.
.WED...NW wind 15 to 25 kt diminishing to up to 20 kt in the
afternoon. Seas 12 to 20 ft.
.WED NIGHT...N wind up to 20 kt. Seas 9 to 14 ft.
.THU THROUGH SAT...NW wind 10 to 25 kt. Seas 6 to 11 ft.

$$

PKZ412-200115-
Bering Sea Offshore 171W to 180 and North of 56N-
329 AM AKST Tue Dec 19 2017

...STORM WARNING TONIGHT AND WEDNESDAY...

.TODAY...SW wind 35 to 45 kt. Seas 27 to 33 ft. Snow showers.
.TONIGHT...SW wind 35 to 50 kt. Seas 18 to 30 ft. Snow and rain.
.WED...SW wind 40 to 55 kt. Seas 20 to 35 ft. Rain.
.WED NIGHT...W wind 15 to 30 kt. Seas 14 to 22 ft.
.THU...N wind 20 to 35 kt. Seas 10 to 18 ft.
.FRI THROUGH SAT...W wind 20 to 35 kt. Seas 9 to 14 ft.

$$

PKZ413-200115-
Bering Sea Offshore 171W to 180 and South of 56N-
329 AM AKST Tue Dec 19 2017

...STORM WARNING TONIGHT AND WEDNESDAY...

.TODAY...SW wind 40 kt. Seas 23 to 29 ft. Snow showers.
.TONIGHT...S wind 35 to 50 kt. Seas 22 to 30 ft. Rain.
.WED...SW wind 45 to 60 kt. Seas 23 to 32 ft subsiding to 16 to
31 ft in the afternoon. Rain.
.WED NIGHT...N wind 20 to 35 kt. Seas 11 to 19 ft.
.THU THROUGH SAT...W wind 25 to 40 kt. Seas 9 to 17 ft.

$$

PKZ414-200115-
Bering Sea Offshore East of 171W-
329 AM AKST Tue Dec 19 2017

...STORM WARNING WEDNESDAY...

.TODAY...SW wind 30 to 40 kt. Seas 15 to 25 ft.
.TONIGHT...SW wind 30 kt becoming 25 to 40 kt after midnight. Seas
17 to 24 ft.
.WED...S wind 35 to 50 kt. Seas 15 to 28 ft.
.WED NIGHT...SE wind 30 to 45 kt. Seas 15 to 27 ft.
.THU THROUGH FRI...SE wind 20 to 35 kt. Seas 10 to 18 ft.
.SAT...W wind 15 to 30 kt. Seas 12 to 17 ft.

$$

225 
FZAK62 PAFC 200032
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
332 PM AKST Tue Dec 19 2017

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-201430-
332 PM AKST Tue Dec 19 2017
.SYNOPSIS FOR CENTRAL BERING SEA...

A 986 mb low will move to 53N 169E this afternoon, then it will 
move to 56N 179W at 979 mb Wed morning, then it will move to 62N 
176W at 973 mb Wed afternoon. A 991 mb low moves to 53N 171E at 
991 mb Wed afternoon then it will move to 52N 177E at 994 mb Thu 
morning. 

$$

PKZ411-201430-
Bering Sea Offshore West of 180 and East of the International
Dateline-
332 PM AKST Tue Dec 19 2017

...GALE WARNING TONIGHT...

.TONIGHT...SW wind 25 to 40 kt becoming W 10 to 25 kt after
midnight. Seas 14 to 22 ft. Snow and rain.
.WED...NW wind 15 to 25 kt becoming W up to 20 kt in the
afternoon. Seas 10 to 18 ft.
.WED NIGHT...SW to NW wind 15 to 30 kt. Seas 10 to 13 ft. Snow.
.THU...N wind 15 to 30 kt. Seas 11 ft.
.THU NIGHT...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.FRI THROUGH SUN...W wind 15 to 30 kt. Seas 7 to 12 ft.

$$

PKZ412-201430-
Bering Sea Offshore 171W to 180 and North of 56N-
332 PM AKST Tue Dec 19 2017

...STORM WARNING THROUGH WEDNESDAY...

.TONIGHT...SW wind 25 to 40 kt increasing to 35 to 50 kt after
midnight. Seas 19 to 27 ft. Rain and snow.
.WED...SW wind 40 to 55 kt. Seas 17 to 32 ft. Rain and snow.
.WED NIGHT...W wind up to 20 kt becoming SE to NE 15 to 30 kt after
midnight. Seas 14 to 22 ft. Rain.
.THU...NE wind 25 to 40 kt. Seas 11 to 18 ft.
.THU NIGHT...NE wind 35 to 50 kt. Seas 13 to 21 ft.
.FRI...NW wind 35 to 50 kt. Seas 13 to 21 ft.
.SAT...W wind 20 to 35 kt. Seas 8 to 13 ft.
.SUN...SW wind 25 kt. Seas 8 to 13 ft.

$$

PKZ413-201430-
Bering Sea Offshore 171W to 180 and South of 56N-
332 PM AKST Tue Dec 19 2017

...STORM WARNING THROUGH WEDNESDAY...

.TONIGHT...S wind 40 to 55 kt. Seas 21 to 28 ft. Rain.
.WED...SW wind 45 to 60 kt diminishing to 25 to 45 kt in the
afternoon. Seas 20 to 30 ft subsiding to 14 to 29 ft in the 
afternoon. Rain.
.WED NIGHT...NW 20 to 35 kt...except SE 35 kt east of 173w. Seas 12 
to 20 ft. Rain.
.THU...N wind 30 to 45 kt. Seas 10 to 18 ft.
.THU NIGHT...NW wind 35 to 50 kt. Seas 16 to 24 ft.
.FRI...NW wind 30 to 45 kt. Seas 14 to 22 ft.
.SAT...W wind 15 to 30 kt. Seas 7 to 12 ft.
.SUN...SW wind 15 to 25 kt. Seas 8 to 12 ft.

$$

PKZ414-201430-
Bering Sea Offshore East of 171W-
332 PM AKST Tue Dec 19 2017

...STORM WARNING WEDNESDAY...

.TONIGHT...SW wind 30 to 40 kt. Seas 16 to 23 ft.
.WED...S wind 40 to 55 kt. Seas 15 to 27 ft.
.WED NIGHT...SE wind 30 to 45 kt. Seas 16 to 26 ft.
.THU...SE wind 25 to 40 kt. Seas 13 to 19 ft.
.THU NIGHT...E wind 30 to 45 kt. Seas 10 to 18 ft.
.FRI...S wind 15 to 30 kt. Seas 11 to 19 ft.
.SAT THROUGH SUN...SW wind 15 to 30 kt. Seas 9 to 17 ft.

$$

034 
FZAK62 PAFC 201242
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
342 AM AKST Wed Dec 20 2017

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-210145-
342 AM AKST Wed Dec 20 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 985 mb low at 57N 176E will move to the northern Bering tonight.
A 994 mb low at 49N 178W will move to 55N 173W at 980 mb Thu 
night, then dissipate Fri morning. A 982 mb low will move to the 
southwestern Gulf Thu afternoon then move to 56N 156W at 976 mb 
Fri morning. 

$$

PKZ411-210145-
Bering Sea Offshore West of 180 and East of the International
Dateline-
342 AM AKST Wed Dec 20 2017

.TODAY...NW to SW wind 15 to 30 kt. Seas 10 to 18 ft.
.TONIGHT...NW wind 10 to 25 kt. Seas 9 to 13 ft. Snow.
.THU...NW wind 15 to 30 kt. Seas 9 to 13 ft.
.THU NIGHT...NW wind 10 to 25 kt. Seas 8 to 13 ft.
.FRI THROUGH SUN...SW wind 15 to 30 kt. Seas 8 to 13 ft.

$$

PKZ412-210145-
Bering Sea Offshore 171W to 180 and North of 56N-
342 AM AKST Wed Dec 20 2017

...STORM WARNING TODAY...

.TODAY...SW wind 40 to 55 kt. Seas 17 to 32 ft. Rain.
.TONIGHT...W wind up to 20 kt becoming NE 15 to 30 kt after
midnight. Seas 15 to 23 ft. Rain.
.THU...NE wind 25 to 40 kt. Seas 12 to 20 ft. Snow and rain.
.THU NIGHT...N wind 30 to 45 kt. Seas 12 to 20 ft.
.FRI THROUGH SAT...NW wind 30 to 45 kt. Seas 12 to 20 ft.
.SUN...SW wind 10 to 25 kt. Seas 9 to 13 ft.

$$

PKZ413-210145-
Bering Sea Offshore 171W to 180 and South of 56N-
342 AM AKST Wed Dec 20 2017

...STORM WARNING TODAY...

.TODAY...SW wind 40 to 55 kt. Seas 20 to 30 ft subsiding to 14 to
29 ft in the afternoon. Rain.
.TONIGHT...W wind 25 to 40 kt becoming N 20 to 35 kt after
midnight. Seas 12 to 20 ft. Rain.
.THU...N wind 20 to 35 kt becoming NW 30 to 45 kt in the
afternoon. Seas 10 to 18 ft. Rain.
.THU NIGHT...NW wind 35 to 50 kt. Seas 15 to 23 ft.
.FRI...NW wind 30 to 45 kt. Seas 14 to 22 ft.
.SAT...W wind 15 to 30 kt. Seas 10 to 18 ft.
.SUN...SW wind 10 to 20 kt. Seas 8 to 13 ft.

$$

PKZ414-210145-
Bering Sea Offshore East of 171W-
342 AM AKST Wed Dec 20 2017

...STORM WARNING TODAY...

.TODAY...S wind 35 to 50 kt. Seas 15 to 27 ft.
.TONIGHT...SE wind 30 to 45 kt. Seas 16 to 26 ft.
.THU...SE wind 25 to 40 kt. Seas 13 to 20 ft. Rain.
.THU NIGHT...E wind 30 to 45 kt. Seas 9 to 17 ft.
.FRI...S wind 20 to 35 kt. Seas 11 to 19 ft.
.SAT...W wind 20 to 35 kt. Seas 10 to 18 ft.
.SUN...W wind 10 to 25 kt. Seas 6 to 11 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
434 PM AKST Sun Dec 17 2017

.ANALYSIS AND UPPER LEVELS...

A weakening positive tilt trough over Southern Alaska is shifting
east this afternoon. Embedded within the larger trough are
numerous smaller scale and weak disturbances, one along the North
Gulf Coast and another moving across the Kuskokwim Delta. An
unstable environment remains over the Gulf of Alaska and along the
immediate coast where snow showers are ongoing. There is a weak
surface trough axis along the North Gulf Coast, otherwise, the
gradient over Southcentral is rather weak. Out west, ridging
building into the Bering is keeping a tight northwest flow
gradient over the Southwest coastline. This is ahead of a
developing bomb cyclone over the far western Bering Sea as a
potential vorticity anomaly is in the process of intersecting a
modest warm front. Himawari satellite imagery is already showing
the classic signs of a powerful low, including a developing
emerging cloud head out of the left exit of the upper jet.

&&

.MODEL DISCUSSION...

The numerical models are in unusually good agreement with the
details of a powerful bomb cyclone over the western Bering
Sea...and the associated front which will cross the Bering Sea and
move inland Monday and Tuesday. The biggest discrepancy in the
models is how much inland precipitation will fall across parts of
Southcentral owing to a low level cross-barrier flow component
which will act to diminish precip values for some locations.
Places like Anchorage, the Copper Basin, and parts of the northern
Kenai Peninsula will likely see some impact of cross-barrier flow
and possibly even some low level warming which may result in mixed
precip on the onset of the event (a mix of rain and snow).

&&

.AVIATION...
PANC...Fog is likely to redevelop during the overnight as mid
level clouds clear out and the low level flow remains weak. This
will likely bring in IFR to LIFR CIGS and VSBYS which will last
through the morning. However, confidence is only moderate since
the coverage of fog is not expected to be widespread.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A weak surface low currently located in the Gulf of Alaska will
slowly weaken tonight while moving off to the east, bringing an
end to the scattered snow showers along the coast by the early
morning hours. A transient ridge will quickly build in behind the
departing low tomorrow morning. Weak flow with clearing skies and
abundant low level moisture will allow areas of dense fog to
reform tonight for locations along the Cook Inlet and Knik Arm.
Besides the fog, skies will be mostly sunny and temperatures will
be noticeably colder compared to the first half of the month.

The ridge will depart quickly to the east as the next storm system
comes barreling through the area from the west by Monday night. A
front will move into southcentral by Tuesday morning and a triple
point low is expected to form south of Homer and move north. Warm
air is expected to advect up from the south and easterly winds
will increase through Turnagain Arm and the Knik River Valley.
This will likely keep the typical downsloped areas, including the
Western Kenai Peninsula, Anchorage, and Palmer, mostly dry and
warmer through the day on Tuesday. It is not until the low passes
to the northeast late Tuesday afternoon that precipitation will
develop over these areas. Colder air filtering in from the NW will
likely change precipitation over to all snow, though total
accumulations should be no more than 1-2". In the Susitna Valley,
favorable midlevel flow from the SW will provide a good push of
moisture up the Cook Inlet brining a decent snow event to
locations along the Parks Highway, especially north of Willow,
where total snowfall is expected to be between 6-8" with localized
amounts near a foot by Tuesday night. A winter storm watch has
therefore been issued for this area. Hatcher Pass will also see
significant snowfall, with 1-1.5 ft of snow falling through the
day on Wednesday.

The low will track across the northern Gulf and Prince William
sound spreading precipitation across coastal areas by late Tuesday
morning. Precipitation should mostly be rain or mixed, though
colder air trapped in Valdez will lead to all snow, with nearly a
foot of snow expected to fall in town through Wednesday morning.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Weak ridging has moved in over southwest Alaska and will remain
overnight bringing a possibility of fog to the area. Then on
Monday morning a front will push in from the west at first
bringing snow to southwest Alaska. This front has a long fetch of
warm air with it that will transition the snow over to rain for
areas at and near the coast. By Tuesday afternoon the front will
have pushed off to the east with cold air coming in behind it.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Over the eastern Bering, high pressure is quickly tracking to the
east. Out west there is a deep low over the far western Bering
with its front draped through the western Aleutians. As the front
moves through the central Aleutians this evening it will bring
strong gusty winds reaching warning level. As it passes early
Monday morning the winds will diminish.

The front is pulling up warm air from the south causing it to
bring rain to the islands. It will track east through the area and
make it to the eastern Bering and Aleutians Monday morning. Cold
westerly flow will follow behind the front bringing snow showers
to the area. Then on Tuesday another warm system will approach the
western Aleutians from the North Pacific.

&&

.LONG TERM FORECAST (Days Tuesday through Saturday)...

The long term forecast remains on track for Tuesday, with snow
expected in the Susitna Valley and along the Chugach Range toward
Valdez. Current snow amounts look to be close to a foot north and
east of Talkeetna, which will bring some much welcome ground cover
in those areas. Details are slightly less certain through Valdez,
but right now snow amounts are expected to be very similar in this
area as well. Unfortunately for snow lovers, this will be a non-
event for Anchorage and the Kenai Peninsula, with an inch or less
expected.

After Tuesday, most of the state will experience a quick shot of
cold air (a.k.a. return to seasonable temperatures) before the
North Pacific ridge builds back in, starting Thursday. The
orientation of the ridge makes a big difference in the forecast,
but models keep trending towards a more negatively tilted ridge,
pushing low pressure systems further westward. Friday and Saturday
a new, strong system moves up from the Gulf of Alaska and has the
potential to bring an atmospheric river for the Southcentral
region. Currently, Kodiak appears to be in the crosshairs, but if
the solutions wobble again, the southern Kenai may see the brunt
of the system. Unfortunately a combination of warm southerly flow
and downsloping across the Southcentral area are currently
indicating more of a wind and rain storm, instead of an early snow
for Christmas.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WSW 145 & NPW 187.
MARINE...Storms 170 173-177 179 411-414.
         Gales 150 155 160 165 170 171 178 180 181 185.
&&

SYNOPSIS AND MODEL DISCUSSION...JA
SOUTHCENTRAL ALASKA...KVP
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DK
LONG TERM...LF