Heavy Freezing Spray Warning 21, NWS Anchorage, AK

597 
FZAK51 PAFC 230058
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
358 PM AKST Mon Jan 22 2018

Coastal Waters Forecast for the Northern Gulf of Alaska Coast
up to 100 nm out including Kodiak Island and Cook Inlet.

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.

PKZ197-231345-
358 PM AKST Mon Jan 22 2018
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...
A 993 mb low 220 nm southeast of Kodiak City will weaken and 
dissipate by Tue afternoon. A 982 mb low Tue afternoon 220 nm
southwest of Hydaburg will move to 365 nm southwest of Hydaburg 
at 993 mb Wed afternoon.


$$

PKZ119-231345-
Cape Suckling to Cape Cleare-
358 PM AKST Mon Jan 22 2018

.TONIGHT...SE wind 20 kt. Seas 6 ft.
.TUE...E wind 20 kt. Seas 6 ft.
.TUE NIGHT...NE wind 20 kt. Seas 6 ft.
.WED AND WED NIGHT...N wind 15 kt. Seas 6 ft.
.THU...NE wind 20 kt. Seas 6 ft.
.FRI THROUGH SAT...NE wind 25 kt. Seas 7 ft.

$$

PKZ120-231345-
Cape Cleare to Gore Point-
358 PM AKST Mon Jan 22 2018

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...E wind 25 kt becoming SE 15 kt after midnight. 
Seas 7 ft. and rain showers.
.TUE...NE wind 15 kt. Seas 6 ft.
.TUE NIGHT...N wind 20 kt. Seas 6 ft.
.WED...N wind 20 kt. Seas 7 ft.
.WED NIGHT...NW wind 25 kt. Seas 7 ft.
.THU...N wind 20 kt. Seas 6 ft.
.FRI THROUGH SAT...NE wind 25 kt. Seas 8 ft.

$$

PKZ121-231345-
Resurrection Bay-
358 PM AKST Mon Jan 22 2018

...SMALL CRAFT ADVISORY TUESDAY NIGHT...

.TONIGHT...N wind 15 kt. Gusts to 25 kt near Seward in the evening. 
Seas 2 ft. Snow showers.
.TUE...N wind 10 kt increasing to 20 kt in the afternoon. Seas 2
ft building to 4 ft in the afternoon. Freezing spray in the 
afternoon. Snow.
.TUE NIGHT...N wind 20 kt increasing to 30 kt after midnight. Seas
5 ft. Freezing spray.
.WED AND WED NIGHT...N wind 30 kt. Seas 7 ft.
.THU THROUGH FRI...N wind 30 kt. Seas 6 ft.
.SAT...N wind 20 kt. Seas 4 ft.

$$

PKZ125-231345-
Prince William Sound-
358 PM AKST Mon Jan 22 2018

.TONIGHT...NE wind 15 kt. Seas 2 ft. Snow showers.
.TUE...NE wind 10 kt becoming N 20 kt in the afternoon. Seas 3 ft.
.TUE NIGHT...N wind 20 kt. Seas 3 ft.
.WED AND WED NIGHT...NW wind 20 kt. Seas 4 ft.
.THU...N wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 4 ft.

$$

PKZ126-231345-
Port Valdez-
358 PM AKST Mon Jan 22 2018

.TONIGHT...NE wind 10 kt in the evening becoming variable less
than 10 kt. Seas 2 ft. Snow showers.
.TUE...NE wind 10 kt increasing to 15 kt in the afternoon. Seas
3 ft. Freezing spray.
.TUE NIGHT...NE wind 20 kt. Seas 4 ft. Freezing spray.
.WED AND WED NIGHT...NE wind 25 kt. Seas 5 ft.
.THU THROUGH FRI...NE wind 25 kt. Seas 5 ft.
.SAT...N wind 20 kt. Seas 4 ft.

$$

PKZ127-231345-
Valdez Narrows-
358 PM AKST Mon Jan 22 2018

...GALE WARNING TONIGHT...

.TONIGHT...N wind 35 kt diminishing to 25 kt after midnight. Seas 3 
ft. Freezing spray. Snow showers.
.TUE...N wind 25 kt. Seas 3 ft. Freezing spray. Snow showers.
.TUE NIGHT...N wind 30 kt. Seas 3 ft. Freezing spray.
.WED...N wind 30 kt. Seas 4 ft.
.WED NIGHT...N wind 35 kt. Seas 4 ft.
.THU THROUGH FRI...N wind 35 kt. Seas 4 ft.
.SAT...N wind 30 kt. Seas 3 ft.

$$

PKZ128-231345-
Valdez Arm-
358 PM AKST Mon Jan 22 2018

...SMALL CRAFT ADVISORY TUESDAY AND TUESDAY NIGHT...

.TONIGHT...NE wind 20 kt. Seas 4 ft. Freezing spray after midnight.
.TUE...NE wind 15 kt increasing to 25 kt in the afternoon. Seas 3
ft building to 5 ft in the afternoon. Freezing spray in the morning.
.TUE NIGHT...NE wind 25 kt. Seas 5 ft.
.WED AND WED NIGHT...NE wind 30 kt. Seas 6 ft.
.THU THROUGH FRI...NE wind 30 kt. Seas 6 ft.
.SAT...NE wind 25 kt. Seas 5 ft.

$$

PKZ129-231345-
Passage Canal-
358 PM AKST Mon Jan 22 2018

.TONIGHT...W wind 10 kt in the evening becoming variable less than
10 kt. Seas 2 ft. Snow.
.TUE...Variable wind 10 kt becoming W 15 kt in the afternoon. Seas
2 ft. Freezing spray in the afternoon. Snow.
.TUE NIGHT...W wind 20 kt. Seas 3 ft. Freezing spray.
.WED AND WED NIGHT...W wind 25 kt. Seas 4 ft.
.THU...W wind 20 kt. Seas 3 ft.
.FRI THROUGH SAT...E wind 15 kt. Seas 2 ft.

$$

PKZ130-231345-
West of Barren Islands including Kamishak Bay-
358 PM AKST Mon Jan 22 2018

...GALE WARNING THROUGH TUESDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 40 kt. Seas 12 ft. Heavy freezing spray.
.TUE...NW wind 45 kt. Seas 12 ft. Heavy freezing spray.
.TUE NIGHT...NW wind 40 kt. Seas 13 ft. Heavy freezing spray.
.WED AND WED NIGHT...NW wind 35 kt. Seas 10 ft.
.THU...NW wind 35 kt. Seas 12 ft.
.FRI THROUGH SAT...N wind 25 kt. Seas 6 ft.

$$

PKZ131-231345-
Barren Islands East-
358 PM AKST Mon Jan 22 2018

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...N wind 35 kt. Seas 9 ft. Freezing spray.
.TUE...NW wind 40 kt. Seas 9 ft. Freezing spray.
.TUE NIGHT...NW wind 40 kt. Seas 18 ft. Freezing spray.
.WED AND WED NIGHT...NW wind 35 kt. Seas 12 ft.
.THU...N wind 35 kt. Seas 12 ft.
.FRI THROUGH SAT...NE wind 25 kt. Seas 8 ft.

$$

PKZ132-231345-
Marmot Island to Sitkinak-
358 PM AKST Mon Jan 22 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...N wind 25 kt except N 30 kt N of Dangerous Cape. 
Seas 8 ft. Freezing spray.
.TUE...N wind 30 kt. Seas 9 ft. Freezing spray.
.TUE NIGHT...NW wind 30 kt. Seas 11 ft. Freezing spray.
.WED AND WED NIGHT...NW wind 35 kt. Seas 12 ft.
.THU...NW wind 40 kt. Seas 12 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 8 ft.

$$

PKZ136-231345-
Chiniak Bay-
358 PM AKST Mon Jan 22 2018

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NW wind 25 kt. Seas 4 ft. Freezing spray.
.TUE...NW wind 20 kt. Seas 3 ft. Freezing spray.
.TUE NIGHT...NW wind 20 kt. Seas 3 ft. Freezing spray.
.WED...NW wind 25 kt. Seas 4 ft.
.WED NIGHT...NW wind 30 kt. Seas 4 ft.
.THU...NW wind 30 kt. Seas 4 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 4 ft.

$$

PKZ137-231345-
Marmot Bay-
358 PM AKST Mon Jan 22 2018

...SMALL CRAFT ADVISORY TONIGHT AND TUESDAY NIGHT...

.TONIGHT...NW wind 25 kt. Seas 4 ft. Freezing spray.
.TUE...NW wind 20 kt. Seas 2 ft. Freezing spray.
.TUE NIGHT...NW wind 25 kt. Seas 3 ft. Freezing spray.
.WED AND WED NIGHT...NW wind 25 kt. Seas 4 ft.
.THU...NW wind 25 kt. Seas 4 ft.
.FRI THROUGH SAT...N wind 20 kt. Seas 5 ft.

$$

PKZ138-231345-
Shelikof Strait-
358 PM AKST Mon Jan 22 2018

...GALE WARNING TUESDAY AND TUESDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas 8 ft. Heavy freezing spray.
.TUE...NW wind 35 kt. Seas 9 ft. Heavy freezing spray.
.TUE NIGHT...NW wind 35 kt. Seas 8 ft. Heavy freezing spray.
.WED AND WED NIGHT...NW wind 30 kt. Seas 7 ft.
.THU...NW wind 30 kt. Seas 8 ft.
.FRI THROUGH SAT...N wind 25 kt. Seas 5 ft.

$$

PKZ139-231345-
Cook Inlet Kalgin Island to Point Bede-
358 PM AKST Mon Jan 22 2018

.TONIGHT...N wind 20 kt. Seas 5 ft. Freezing spray.
.TUE...N wind 15 kt. Seas 4 ft. Freezing spray.
.TUE NIGHT...N wind 15 kt. Seas 5 ft. Freezing spray.
.WED AND WED NIGHT...N wind 15 kt. Seas 4 ft.
.THU THROUGH SAT...NE wind 20 kt. Seas 5 ft.

$$

PKZ140-231345-
Cook Inlet North of Kalgin Island-
358 PM AKST Mon Jan 22 2018

.TONIGHT...NE wind 10 kt. 
.TUE...NE wind 10 kt. 
.TUE NIGHT...NE wind 10 kt. 
.WED...NE wind 10 kt. 
.WED NIGHT...Variable wind less than 10 kt. 
.THU THROUGH SAT...N wind 15 kt. 

$$

PKZ141-231345-
Kachemak Bay-
358 PM AKST Mon Jan 22 2018

.TONIGHT...NE wind 15 kt. Seas 2 ft. Snow showers.
.TUE...N wind 15 kt. Seas 2 ft. Freezing spray.
.TUE NIGHT...N wind 15 kt. Seas 2 ft. Freezing spray.
.WED...N wind 20 kt. Seas 2 ft.
.WED NIGHT...N wind 15 kt. Seas 2 ft.
.THU THROUGH SAT...NE wind 20 kt. Seas 3 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
446 PM AKST Sun Jan 21 2018

.ANALYSIS AND UPPER LEVELS...
A highly amplified pattern remains over the region. There is an
upper level trough over mainland Alaska extending into the Gulf.
An upper level closed low is at the southern end of this trough
over the southwest Gulf, and another closed low further north
along the Arctic coast of the state. There is a blocking ridge
over the central Bering Sea, with a trough over the southwest
Bering. Strong northerly flow is over the west coast of the
mainland and the eastern Bering Sea. Weak ridging is over the
Yukon extending into inland portions of south central Alaska. Some
moisture is over the northern Gulf that is bringing precipitation
to the Gulf coast and extending inland to some degree. There is a
weakening negatively tilted front over the western Aleutians and
southwest Bering.

&&

.MODEL DISCUSSION...
The numerical models are in fairly good agreement through Tuesday
afternoon on the major synoptic features. Some differences are
evident over the Gulf with how the models handle the numerous weak
surface lows. There is also some disagreement on precipitation,
especially for inland areas of Southcentral. Therefore forecast
confidence is near normal.

&&

.AVIATION...
PANC...Some snow showers are possible during the TAF period. This
could briefly lower conditions to MVFR mainly on Monday afternoon,
otherwise VFR is expected to be predominant at this time.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2: Monday and
Tuesday)...

The weather is becoming increasingly active and interesting for
Southcentral over the next couple days. Here are some details:

Tonight:
Off-and-on snow showers and flurries are ongoing across much of
Southcentral this evening. The snow is being caused by a weak
disturbance progressing northwestward out of the Gulf towards a
digging upper level low currently over far northern Alaska. No
significant accumulations of snow are expected from this first
wave as much of the energy associated with it is being sheared
apart. The flurry threat, if you can call it such, will end after
midnight. Otherwise, outflow winds through the gaps continue this
evening with a weak surface low over the northern Gulf helping
drag the cold air now well entrenched over interior Alaska out
through the gaps. As this low weakens tonight, so too will the
winds. The cold, dry air moving over the relatively warmer waters
of the Gulf and Prince William Sound is making for good conditions
for mariners to experience heavy freezing spray in the windier
locations through Kamishak Bay, the Barren Islands region,
Shelikof Strait, and perhaps some local concerns in any narrow
gaps and fjords.

Monday:
During the day will be the calm between systems, though scattered
snow showers will continue through western Prince William Sound
and the north Gulf Coast through much of the day. Any small lows
over the northern Gulf will be absorbed into a stronger low over
the southern Gulf, so relaxing pressure gradients will continue to
have winds area-wide on the decline through the day.

Monday Night into Tuesday:
Upper level dynamics will be the forcing for the next snow event
for nearly all of Southcentral. An upper level low over the
southern Gulf will slowly track northward overnight. To its north,
a shortwave extending from the upper low will circulate westward
across the northern Gulf towards Southcentral. Meanwhile, the
aforementioned upper low over far northern Alaska will be moving
southbound as a trough over the Alaska Range slowly moves
southeastward. As a result, a zone of deformation and stronger
lift will develop over most of Southcentral and bring a long-
duration light snow event through those areas starting Monday
evening and persisting right through Tuesday morning.

Throughout this event, winds in the lowest levels will be light
with no downsloping expected, the current thinking is that the
entire area will get roughly equal amounts of snow. No one area
looks to be favored over any other with this event. Temperatures
throughout the event will be in the teens to low 20s, which is
plenty cold enough for the snow to be a light, powdery, fast-
accumulating consistency. Fortunately the light winds will
preclude there being any visibility restrictions from blowing
snow.

On Tuesday afternoon, the upper level trough over the Alaska Range
will have moved eastward over Southcentral, ending the snow.
Behind it Tuesday night, a sharp line of clearing skies will also
progress eastward, resulting in lots of sunshine by Wednesday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...

The main forecast challenge in the short term is how low will the
wind chill values drop tonight, mainly for the Kuskokwim Delta.
With abundant clear skies across the southwest Mainland,
radiational cooling won't be a problem tonight. Wind speeds of 15
to 25 mph are anticipated for the upper parts of the region, when
combined with the low temperatures forecasted drops the wind
chill values to lower than -40 F. Thus, the wind chill advisory
issued earlier this afternoon looks good. Further upstream into
the Kuskokwim Valley, temperatures will be much colder. However,
wind speeds look to remain less than 15 mph, which is one of the
criteria needed for a advisory.

Otherwise, a persistent area of high pressure across the Bering
will continue to funnel colder air into the area in an offshore
flow regime, with no sensible change in the pattern seen through
the next few days.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

An area of high pressure will remain anchored across central
portions of the Bering Sea/Aleutians through the next few days.
This creates a rather stagnant pattern with a stalled gale force
front remaining in place across western portions of the chain, and
cold air continuing to pour into eastern portions of the Bering
and into the eastern portions of the Aleutians/AKpen. This will
bring continued freezing spray concerns to these eastern areas
through the period.

&&

.LONG TERM FORECAST (Days 3 through 7)...

Beginning the extended period forecast Tuesday night, there will
be a rather potent cold upper level vortex over the northwest part
of Alaska with associated troughing extending into the Gulf of
Alaska. Low level cyclonic flow will preferentially wrap around
the Alaska Range into the Bering Sea. Snow showers over parts of
Southcentral will quickly be end late Tuesday (although they may
linger longer over the Copper Basin) as strong offshore flow
increases in response to cold air advection. Temperatures will
continue to drop across all of Southern Alaska as 850 temperatures
plummet to -20 to -30C on Thursday as the upper vortex moves
south across the region. As the upper low digs into the North
Pacific, secondary cyclogenesis will develop in the Gulf with
increasing chances of coastal precipitation (in the form of snow)
Thursday into Saturday. Some locations such as Kodiak Island may
see the potential for good accumulations should the setup develop
as current global models depict...stay tuned.

Otherwise, the pattern looks to remain dominated by the eventual
large trough over the North Pacific into the Gulf of Alaska, along
with high latitude blocking over Eastern Siberia, for the
remainder of the weekend into early next week. This will likely
result in dry and continued colder than average inland weather as
the general storm track remains south of the forecast area.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Wind Chill Advisory 155.
MARINE...Gale 128 130 131 138 150 155 165 172 180
         Heavy Freezing Spray 130 131 138 150 155 160 165 180 181.

&&

SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...JW
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...JA