Small Craft Advisory 930, NWS Anchorage, AK

650 
FZAK51 PAFC 060233 AAA
CWFAER

Coastal Waters Forecast...UPDATED
National Weather Service Anchorage AK
533 PM AKST Tue Dec 5 2017

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.

PKZ197-061515-
533 PM AKST Tue Dec 5 2017
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...
A 999 mb low in the North Pacific Wed afternoon moves to 40 nm 
south of Cordova at 1001 mb and then moves inland Thu afternoon. 
A strong front remains nearly stationary in the eastern Gulf 
through Thu afternoon.

$$

PKZ119-061515-
Cape Suckling to Cape Cleare-
533 PM AKST Tue Dec 5 2017

...GALE WARNING THROUGH Wednesday...

.TONIGHT...S wind 20 kt becoming SE 35 kt after midnight. W of
Middleton Island...S wind 15 kt becoming NE after midnight.  Seas
12 ft building to 18 ft after midnight. Rain. 
.WED...SE wind 40 kt. W of Middleton Island...SE wind 20 kt. 
Seas 21 ft. Rain. 
.WED NIGHT...S wind 15 kt. Seas 17 ft. 
.THU...SE wind 35 kt. Seas 14 ft. 
.THU NIGHT...E wind 45 kt. Seas 19 ft. 
.FRI...SE wind 45 kt. Seas 19 ft. 
.SAT...SE wind 30 kt. Seas 17 ft. 
.SUN...SE wind 25 kt. Seas 16 ft.

$$

PKZ120-061515-
Cape Cleare to Gore Point-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 15 kt in the evening becoming Variable 10 kt. 
Seas 10 ft. 
.WED...N wind 20 kt. Seas 12 ft. 
.WED NIGHT...Variable wind 10 kt becoming E 25 kt after midnight.
Seas 12 ft. Rain. 
.THU...E wind 20 kt. Seas 12 ft. 
.THU NIGHT...E wind 30 kt. Seas 12 ft. 
.FRI...E wind 30 kt. Seas 15 ft. 
.SAT THROUGH SUN...E wind 25 kt. Seas 17 ft.

$$

PKZ121-061515-
Resurrection Bay-
533 PM AKST Tue Dec 5 2017

.TONIGHT...S wind 20 kt becoming variable wind less than 10 kt 
after midnight. Seas 4 ft subsiding to 2 ft after midnight. Rain.
.WED...N wind 20 kt. Seas 4 ft. 
.WED NIGHT...N wind 15 kt diminishing to 10 kt after midnight.
Seas 3 ft. Rain. 
.THU AND THU NIGHT...N wind 20 kt. Seas 4 ft. 
.FRI...N wind 20 kt. Seas 4 ft. 
.SAT THROUGH SUN...N wind 15 kt. Seas 3 ft.

$$

PKZ125-061515-
Prince William Sound-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY WEDNESDAY...

.TONIGHT...SE wind 20 kt becoming E 10 kt after midnight. 
Seas 4 ft subsiding to 2 ft after midnight. Rain. 
.WED...NE wind 15 kt becoming SE 25 kt in the afternoon.  
Seas 4 ft. Rain. 
.WED NIGHT...SW wind 10 kt becoming NE 15 kt after midnight. 
Seas 3 ft. Rain. 
.THU...E wind 25 kt. Seas 6 ft. 
.THU NIGHT...NE wind 35 kt. Seas 7 ft. 
.FRI...E wind 35 kt. Seas 7 ft. 
.SAT...E wind 20 kt. Seas 3 ft. 
.SUN...E wind 15 kt. Seas 3 ft.

$$

PKZ126-061515-
Port Valdez-
533 PM AKST Tue Dec 5 2017

.TONIGHT...E wind 10 kt. Seas 2 ft. Rain. 
.WED...NE wind 15 kt. Seas 3 ft. Rain. 
.WED NIGHT...E wind 15 kt. Seas 3 ft. Rain and snow showers. 
.THU...E wind 10 kt. Seas 2 ft. 
.THU NIGHT...E wind 15 kt. Seas 3 ft. 
.FRI...E wind 15 kt. Seas 3 ft. 
.SAT...E wind 10 kt. Seas 2 ft. 
.SUN...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ127-061515-
Valdez Narrows-
533 PM AKST Tue Dec 5 2017

.TONIGHT...NE wind 20 kt diminishing to 10 kt after midnight. 
Seas 3 ft. Rain. 
.WED...NE wind 10 kt. Seas 2 ft. Rain and snow. 
.WED NIGHT...NE wind 20 kt. Seas 3 ft. Rain with snow. 
.THU AND THU NIGHT...NE wind 25 kt. Seas 3 ft. 
.FRI...NE wind 20 kt. Seas 3 ft. 
.SAT THROUGH SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ128-061515-
Valdez Arm-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY WEDNESDAY...

.TONIGHT...NE wind 20 kt. Seas 3 ft. Rain. 
.WED...E wind 25 kt. Seas 5 ft. Rain. 
.WED NIGHT...SE wind 15 kt becoming NE after midnight.  Seas
3 ft. Rain. 
.THU AND THU NIGHT...NE wind 20 kt. Seas 4 ft. 
.FRI...NE wind 20 kt. Seas 4 ft. 
.SAT THROUGH SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ129-061515-
Passage Canal-
533 PM AKST Tue Dec 5 2017

.TONIGHT...E wind 15 kt. Seas 2 ft. Rain. 
.WED...W wind 10 kt. Seas 3 ft. 
.WED NIGHT...W wind 10 kt becoming E 15 kt after midnight.  Seas
2 ft. Rain showers. 
.THU...E wind 15 kt. Seas 2 ft. 
.THU NIGHT...E wind 25 kt. Seas 4 ft. 
.FRI...E wind 25 kt. Seas 4 ft. 
.SAT...E wind 20 kt. Seas 3 ft. 
.SUN...E wind 15 kt. Seas 2 ft.

$$

PKZ130-061515-
West of Barren Islands including Kamishak Bay-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY TONIGHT AND WEDNESDAY NIGHT...

.TONIGHT...S wind 25 kt becoming SW 10 kt after midnight.  Seas
6 ft. 
.WED...NW wind 15 kt. Seas 4 ft. 
.WED NIGHT...N wind 15 kt becoming NE 30 kt after midnight.  Seas
3 ft building to 9 ft after midnight. 
.THU AND THU NIGHT...NE wind 30 kt. Seas 11 ft. 
.FRI...E wind 30 kt. Seas 11 ft. 
.SAT...E wind 20 kt. Seas 8 ft. 
.SUN...E wind 20 kt. Seas 5 ft.

$$

PKZ131-061515-
Barren Islands East-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 20 kt in the evening becoming variable 10 kt.
Seas 10 ft. 
.WED...NW wind 20 kt. Seas 10 ft. 
.WED NIGHT...E wind 25 kt. Seas 12 ft. 
.THU...E wind 15 kt. Seas 12 ft. 
.THU NIGHT...E wind 25 kt. Seas 12 ft. 
.FRI...E wind 30 kt. Seas 15 ft. 
.SAT THROUGH SUN...E wind 25 kt. Seas 16 ft.

$$

PKZ132-061515-
Marmot Island to Sitkinak-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 15 kt in the evening becoming variable 10 kt.
Seas 9 ft. 
.WED...N wind 20 kt. Seas 10 ft. 
.WED NIGHT...NE wind 25 kt. Seas 12 ft. 
.THU AND THU NIGHT...E wind 20 kt. Seas 12 ft. 
.FRI...SE wind 25 kt. Seas 15 ft. 
.SAT THROUGH SUN...SE wind 20 kt. Seas 15 ft.

$$

PKZ136-061515-
Chiniak Bay-
533 PM AKST Tue Dec 5 2017

.TONIGHT...SW wind 15 kt in the evening becoming variable  less
than 10 kt. Seas 2 ft. 
.WED...NW wind 10 kt increasing to 15 kt in the afternoon.  Seas
2 ft. 
.WED NIGHT...N wind 10 kt becoming NE 15 kt after midnight.  Seas
2 ft building to 4 ft after midnight. 
.THU...E wind 10 kt. Seas 3 ft. 
.THU NIGHT...E wind 20 kt. Seas 7 ft. 
.FRI THROUGH SAT...SE wind 20 kt. Seas 7 ft. 
.SUN...E wind 15 kt. Seas 4 ft.

$$

PKZ137-061515-
Marmot Bay-
533 PM AKST Tue Dec 5 2017

.TONIGHT...SW wind 10 kt in the evening becoming variable  less
than 10 kt. Seas 2 ft. 
.WED...NW wind 10 kt increasing to 15 kt in the afternoon.  Seas
2 ft. 
.WED NIGHT...N wind 10 kt becoming NE 20 kt after midnight.  Seas
2 ft building to 6 ft after midnight. 
.THU...E wind 10 kt. Seas 3 ft. 
.THU NIGHT...NE wind 20 kt. Seas 6 ft. 
.FRI THROUGH SUN...E wind 20 kt. Seas 7 ft.

$$

PKZ138-061515-
Shelikof Strait-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY WEDNESDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 5 ft subsiding to 3 ft after
midnight. 
.WED...Variable wind 10 kt. Seas 2 ft. 
.WED NIGHT...NE wind 15 kt increasing to 30 kt after midnight.
Seas 4 ft building to 8 ft after midnight. 
.THU...NE wind 25 kt. Seas 7 ft. 
.THU NIGHT...NE wind 30 kt. Seas 10 ft. 
.FRI...NE wind 25 kt. Seas 8 ft. 
.SAT THROUGH SUN...E wind 20 kt. Seas 5 ft.

$$

PKZ139-061515-
Cook Inlet Kalgin Island to Point Bede-
533 PM AKST Tue Dec 5 2017

...SMALL CRAFT ADVISORY WEDNESDAY NIGHT...

.TONIGHT...S wind 20 kt. Seas 6 ft subsiding to 4 ft  after
midnight. 
.WED...NW wind 10 kt becoming N 15 kt in the afternoon.  Seas
2 ft building to 4 ft in the afternoon. 
.WED NIGHT...N wind 15 kt becoming NE 30 kt after midnight.  Seas
3 ft building to 8 ft after midnight. 
.THU...NE wind 30 kt. Seas 8 ft. 
.THU NIGHT...NE wind 30 kt. Seas 11 ft. 
.FRI...NE wind 30 kt. Seas 11 ft. 
.SAT THROUGH SUN...NE wind 15 kt. Seas 4 ft.

$$

PKZ140-061515-
Cook Inlet North of Kalgin Island-
533 PM AKST Tue Dec 5 2017

.TONIGHT...E wind 10 kt. Seas 3 ft. 
.WED...Variable wind less than 10 kt becoming N 10 kt  in the
afternoon. Seas 3 ft. 
.WED NIGHT...Variable wind less than 10 kt becoming N 20 kt 
after midnight. Seas 2 ft building to 4 ft after midnight. 
.THU...NE wind 20 kt. Seas 4 ft. 
.THU NIGHT...N wind 25 kt. Seas 9 ft. 
.FRI...NE wind 25 kt. Seas 9 ft. 
.SAT THROUGH SUN...NE wind 15 kt. Seas 4 ft.

$$

PKZ141-061515-
Kachemak Bay-
533 PM AKST Tue Dec 5 2017

.TONIGHT...S wind 15 kt diminishing to 10 kt after midnight. 
Seas 2 ft. 
.WED...Variable wind less than 10 kt becoming N 15 kt in the
afternoon. Seas 2 ft. 
.WED NIGHT...NE wind 10 kt increasing to 15 kt after midnight.
Seas 2 ft. 
.THU...NE wind 15 kt. Seas 2 ft. 
.THU NIGHT...NE wind 20 kt. Seas 3 ft. 
.FRI...NE wind 20 kt. Seas 4 ft. 
.SAT THROUGH SUN...E wind 15 kt. Seas 3 ft.

$$

708 
FZAK51 PAFC 061223
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
323 AM AKST Wed Dec 6 2017

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.

PKZ197-070145-
323 AM AKST Wed Dec 6 2017
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A 988 mb North Pacific low moves 200 nm southwest of Sitkinak
tonight at 986 mb. The low then moves inland Thu afternoon. A strong
front remains nearly stationary in the eastern Gulf through Thu 
night.


$$

PKZ119-070145-
Cape Suckling to Cape Cleare-
323 AM AKST Wed Dec 6 2017

...GALE WARNING TODAY AND THURSDAY...

.TODAY...SE wind 35 kt. Seas 21 ft. Rain.
.TONIGHT...NE wind 20 kt becoming E 30 kt after midnight. Seas
17 ft.
.THU...SE wind 35 kt increasing to 45 kt in the afternoon. Seas
16 ft. Rain.
.THU NIGHT...SE wind 50 kt. Seas 22 ft.
.FRI...SE wind 45 kt. Seas 21 ft.
.SAT...SE wind 30 kt. Seas 17 ft.
.SUN...SE wind 25 kt. Seas 21 ft.

$$

PKZ120-070145-
Cape Cleare to Gore Point-
323 AM AKST Wed Dec 6 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...N wind 15 kt. Seas 12 ft.
.TONIGHT...NE wind 20 kt becoming E 30 kt after midnight. Seas
13 ft. Rain.
.THU...E wind 30 kt. Seas 15 ft. Rain.
.THU NIGHT...SE wind 30 kt. Seas 14 ft.
.FRI...E wind 30 kt. Seas 15 ft.
.SAT THROUGH SUN...E wind 25 kt. Seas 19 ft.

$$

PKZ121-070145-
Resurrection Bay-
323 AM AKST Wed Dec 6 2017

.TODAY...N wind 10 kt increasing to 15 kt this afternoon. Seas 3 ft.
.TONIGHT...N wind 15 kt. Seas 3 ft. Rain.
.THU...N wind 15 kt. Seas 3 ft. Rain.
.THU NIGHT...N wind 20 kt. Seas 4 ft.
.FRI...N wind 20 kt. Seas 4 ft.
.SAT THROUGH SUN...N wind 15 kt. Seas 3 ft.

$$

PKZ125-070145-
Prince William Sound-
323 AM AKST Wed Dec 6 2017

...GALE WARNING THURSDAY...

.TODAY...E wind 10 kt becoming N 15 kt in the afternoon. Seas 3
ft. Rain.
.TONIGHT...NE wind 20 kt. Seas 2 ft building to 4 ft after
midnight. Rain.
.THU...E wind 25 kt increasing to 35 kt in the afternoon. Seas 4
ft building to 7 ft in the afternoon. Rain.
.THU NIGHT...E wind 35 kt. Seas 7 ft.
.FRI...E wind 35 kt. Seas 7 ft.
.SAT...E wind 20 kt. Seas 3 ft.
.SUN...E wind 15 kt. Seas 3 ft.

$$

PKZ126-070145-
Port Valdez-
323 AM AKST Wed Dec 6 2017

.TODAY...NE wind 10 kt. Seas 2 ft. Rain.
.TONIGHT...E wind 15 kt. Seas 3 ft. Rain and snow showers.
.THU...E wind 10 kt. Seas 2 ft. Rain.
.THU NIGHT...E wind 15 kt. Seas 3 ft.
.FRI...E wind 15 kt. Seas 3 ft.
.SAT...E wind 10 kt. Seas 2 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ127-070145-
Valdez Narrows-
323 AM AKST Wed Dec 6 2017

...SMALL CRAFT ADVISORY TONIGHT AND THURSDAY...

.TODAY...NE wind 15 kt. Seas 3 ft. Rain.
.TONIGHT...NE wind 25 kt. Seas 3 ft. Rain with snow.
.THU...NE wind 25 kt. Seas 3 ft. Rain.
.THU NIGHT...NE wind 25 kt. Seas 3 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 3 ft.
.SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ128-070145-
Valdez Arm-
323 AM AKST Wed Dec 6 2017

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...NE wind 15 kt. Seas 3 ft. Rain.
.TONIGHT...NE wind 20 kt. Seas 4 ft. Rain.
.THU...NE wind 25 kt. Seas 5 ft. Rain.
.THU NIGHT...NE wind 25 kt. Seas 5 ft.
.FRI...NE wind 20 kt. Seas 4 ft.
.SAT THROUGH SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ129-070145-
Passage Canal-
323 AM AKST Wed Dec 6 2017

.TODAY...W wind 10 kt increasing to 15 kt in the afternoon. Seas
2 ft. Rain.
.TONIGHT...W wind 15 kt becoming E after midnight. Seas 2 ft. Rain
showers.
.THU...E wind 20 kt. Seas 3 ft. Rain.
.THU NIGHT...E wind 25 kt. Seas 4 ft.
.FRI...E wind 25 kt. Seas 4 ft.
.SAT...E wind 20 kt. Seas 3 ft.
.SUN...E wind 15 kt. Seas 2 ft.

$$

PKZ130-070145-
West of Barren Islands including Kamishak Bay-
323 AM AKST Wed Dec 6 2017

...GALE WARNING TONIGHT AND THURSDAY...

.TODAY...NW wind 15 kt. Seas 4 ft.
.TONIGHT...N wind 25 kt becoming NE 45 kt after midnight. Seas 9
ft building to 17 ft after midnight.
.THU...NE wind 40 kt diminishing to 30 kt in the afternoon. Seas
17 ft subsiding to 12 ft in the afternoon. Rain.
.THU NIGHT...E wind 30 kt. Seas 8 ft.
.FRI...E wind 30 kt. Seas 8 ft.
.SAT...E wind 20 kt. Seas 8 ft.
.SUN...E wind 20 kt. Seas 5 ft.

$$

PKZ131-070145-
Barren Islands East-
323 AM AKST Wed Dec 6 2017

...GALE WARNING TONIGHT...

.TODAY...N wind 20 kt. Seas 10 ft.
.TONIGHT...NE wind 25 kt becoming E 35 kt after midnight. Seas
12 ft.
.THU...SE wind 30 kt becoming E 20 kt in the afternoon. Seas 14
ft. Rain.
.THU NIGHT...SE wind 20 kt. Seas 12 ft.
.FRI...E wind 30 kt. Seas 14 ft.
.SAT THROUGH SUN...E wind 25 kt. Seas 18 ft.

$$

PKZ132-070145-
Marmot Island to Sitkinak-
323 AM AKST Wed Dec 6 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...Variable wind 10 kt becoming NE 20 kt in the afternoon.
Seas 10 ft.
.TONIGHT...NE wind 30 kt. Seas 15 ft.
.THU...SE wind 30 kt diminishing to 20 kt in the afternoon. Seas
14 ft.
.THU NIGHT...S wind 20 kt. Seas 12 ft.
.FRI...E wind 25 kt. Seas 13 ft.
.SAT...SE wind 20 kt. Seas 15 ft.
.SUN...SE wind 20 kt. Seas 18 ft.

$$

PKZ136-070145-
Chiniak Bay-
323 AM AKST Wed Dec 6 2017

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...NW wind 10 kt. Seas 2 ft.
.TONIGHT...N wind 20 kt. Seas 6 ft.
.THU...SE wind 25 kt diminishing to 15 kt in the afternoon. Seas
7 ft subsiding to 4 ft in the afternoon. Rain.
.THU NIGHT...S wind 20 kt. Seas 4 ft.
.FRI THROUGH SAT...SE wind 20 kt. Seas 7 ft.
.SUN...E wind 15 kt. Seas 4 ft.

$$

PKZ137-070145-
Marmot Bay-
323 AM AKST Wed Dec 6 2017

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...NW wind 10 kt. Seas 2 ft.
.TONIGHT...NE wind 20 kt. Seas 4 ft building to 7 ft after
midnight. Widespread rain showers.
.THU...SE wind 25 kt diminishing to 15 kt in the afternoon. Seas
9 ft subsiding to 4 ft in the afternoon. Rain.
.THU NIGHT...SE wind 15 kt. Seas 3 ft.
.FRI THROUGH SUN...E wind 20 kt. Seas 7 ft.

$$

PKZ138-070145-
Shelikof Strait-
323 AM AKST Wed Dec 6 2017

...GALE WARNING TONIGHT AND THURSDAY...

.TODAY...Variable wind 10 kt. Seas 2 ft.
.TONIGHT...NE wind 25 kt increasing to 40 kt after midnight. Seas
8 ft building to 17 ft after midnight.
.THU...NE wind 40 kt diminishing to 30 kt in the afternoon. Seas
17 ft subsiding to 12 ft in the afternoon. Rain and snow.
.THU NIGHT...E wind 25 kt. Seas 6 ft.
.FRI...NE wind 25 kt. Seas 5 ft.
.SAT THROUGH SUN...E wind 20 kt. Seas 5 ft.

$$

PKZ139-070145-
Cook Inlet Kalgin Island to Point Bede-
323 AM AKST Wed Dec 6 2017

...GALE WARNING TONIGHT AND THURSDAY...

.TODAY...NW wind 10 kt. Seas 2 ft building to 4 ft in the
afternoon.
.TONIGHT...N wind 25 kt increasing to 35 kt after midnight. Seas
9 ft building to 13 ft after midnight. Freezing spray.
.THU...NE wind 35 kt becoming N 25 kt in the afternoon. Seas 12
ft. Snow and rain.
.THU NIGHT...NE wind 30 kt. Seas 8 ft.
.FRI...NE wind 30 kt. Seas 8 ft.
.SAT THROUGH SUN...NE wind 15 kt. Seas 4 ft.

$$

PKZ140-070145-
Cook Inlet North of Kalgin Island-
323 AM AKST Wed Dec 6 2017

...SMALL CRAFT ADVISORY TONIGHT AND THURSDAY...

.TODAY...NE wind 10 kt. Seas 3 ft.
.TONIGHT...N wind 15 kt increasing to 25 kt after midnight. Seas
4 ft building to 7 ft after midnight. Freezing spray.
.THU...N wind 25 kt. Seas 7 ft. Freezing spray. Snow.
.THU NIGHT...N wind 25 kt. Seas 6 ft.
.FRI...NE wind 25 kt. Seas 6 ft.
.SAT THROUGH SUN...NE wind 15 kt. Seas 4 ft.

$$

PKZ141-070145-
Kachemak Bay-
323 AM AKST Wed Dec 6 2017

.TODAY...Variable wind less than 10 kt becoming N 10 kt in the
afternoon. Seas 2 ft.
.TONIGHT...NE wind 20 kt. Seas 3 ft.
.THU...E wind 15 kt becoming NE 10 kt in the afternoon. Seas 3 ft.
Rain.
.THU NIGHT...E wind 20 kt. Seas 3 ft.
.FRI...NE wind 20 kt. Seas 4 ft.
.SAT THROUGH SUN...E wind 15 kt. Seas 3 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
524 AM AKST Tue Dec 5 2017

.ANALYSIS AND UPPER LEVELS...

A deep highly amplified trough over the Bering and eastern
Aleutians is causing plentiful active weather across Southern
Alaska this morning. Around it lies a strong jet, representing the
dividing line between warm and cold air. For southern mainland
Alaska, this means the jet is aligned nearly due south to north,
causing an amplified ridge to develop across western North America
and eastern Alaska. As Southcentral lies underneath the core of
the strongest part of the jet, it is acting as a conveyor belt for
storm after storm to track northward out of the Pacific and slam
into the north Gulf Coast. Waves in the jet are causing those
storms to target different portions of the coastline for each one,
but, in short, a very wet pattern continues for Southcentral. Over
Southwest Alaska and especially the Bering, the atmosphere is far
more unstable, and thus, more convective with cold air aloft. So
the precipitation is much more spotty. The southerly flow into
Southcentral is keeping temperatures very mild. Anchorage got to
44 degrees yesterday, remaining just shy of the record. Thus,
precipitation-type concerns remain, and can at times be entirely
dependent on the intensity of the falling precip. Meanwhile
over Southwest Alaska, more cold air in place is keeping most of
the precipitation in the form of snow.

&&

.MODEL DISCUSSION...

Continuing the pattern of the past several nights, the models are
in decent agreement through the first 24 hours or so, getting a
better handling of the next few waves of moisture tracking north
towards the Gulf Coast. Beyond that, they continue to differ
immensely, making the forecast difficult once again beyond that
time frame. In addition, the small differences between the models,
on things such as storm track, end up making a world of difference
regarding impacts to the forecast. For Anchorage for example, the
track of the low impacting Southcentral on Wednesday could mean
the difference between downsloping and warm temperatures again, or
the return of cold air and a snowfall. The difference between
those two very different solutions is just a matter of 50 miles or
so east or west. The further west, the less chance for snow and
greater for warm temperatures, and vice versa. The models are
still honing in on their chosen solution. Thus, needless to say,
much of the forecast to that level of detail remains low
confidence. Much more confidence exists in the forecast for
Southcentral to remain well above normal for temperatures, and
continue to deal with round after round of moisture from the
subtropical Pacific. Meanwhile Southwest Alaska and the Bering
will remain relatively tranquil, much more seasonable
temperature-wise, and more showery.

&&

.AVIATION...
PANC...The latest round of precipitation has largely left the
Anchorage area to the west, though a lingering shower or two is
possible through the early morning. Winds may briefly turn out of
the southeast late this afternoon and evening as a weak wave
brings the threat for additional rain and/or snow showers. The
next more major storm system moves in Wednesday morning, with snow
expected. Most indications are for the heaviest snow to begin
after 18Z, and thus the worst conditions are not yet included in
the TAF.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
An atmospheric river is aiming at the Prince William Sound area
for the next few days. The series of lows riding up this river
will kick off heavier times of precipitation. Thompson Pass will
see some of the heaviest snowfall with the greatest rates falling
between midnight tonight and late afternoon Wednesday. Snow will
mix with or turn to rain just outside Valdez which will limit snow
amounts in town there. Heavy snow is also likely to fall from
Glennallen southward in the Copper River Basin as well.
Gusty southerly winds will occur along the Copper River and will
complicate things a bit. These winds will cause limited
visibilities in blowing snow as well as bring in the possibility
of freezing rain toward Glennallen. Typically the gusty southerly
winds downslope the precipitation but the depth of the moisture
in the atmospheric river will be enough to override the full
effect of the downsloping.

Anchorage and the Matanuska Valley will be on the western
periphery of this system. What this means is that temperatures
will be cold enough for precipitation tonight and Wednesday to be
all snow. There will be a sharp edge to where the snow diminishes
and Anchorage will be near that line. Snow will likely be heavier
in the Palmer and Wasilla areas just because they are farther
east. There is a good chance that advisory level snow will fall in
both the Anchorage and Matanuska Valley from late tonight through
most of the day Wednesday. However, there is still a great amount
of uncertainty as to where the line of quickly diminishing snow
will be with models ranging by a factor of three on the amount of
snow. Therefore, will wait at least another model run to hopefully
get a better handle on where the heaviest snow will be as it is
possible the Anchorage and Matanuska Valley will see just a few
inches over the whole event. It will be that sharp of a dividing
line.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
As the gradually filling low just offshore of the Y-K Delta coast
drifts to the north-northwest today, snow showers along the
Kuskokwim Delta coast will gradually taper off. An area of
deformation will bring a fairly narrow band of moderate to
briefly heavy snow to the greater Bristol Bay area north and east
of King Salmon north to around Sleetmute.

A cold, troughy pattern will persist across Southwest Alaska
tonight through Wednesday with small shortwaves bringing
additional scattered snow showers through at times. Strong
southerly flow into the Gulf of Alaska will begin pushing a warmer
air mass up along the east side of the Aleutian Range Wednesday
night and Thursday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A broad trough with abundant cold air aloft will keep the Bering
and Aleutians well supplied with scattered snow showers and an
occasionally isolated thunderstorm through midweek. A north
Pacific frontal system will slide south of the western Aleutians
tonight and then continue east to be just south of the central
Aleutians on Wednesday. This low will then turn to more to the
southeast Wednesday night, tracking clear of the area Thursday.

&&

.LONG TERM FORECAST (Days 3 through 7)...
The mid/long term forecast beginning Wednesday night has ridging
over southeast Alaska with a longwave trough extending through the
Bering. In the base of the trough a low south of the Central
Aleutians will track east before dissipating. Meanwhile, multiple
waves will move up the western side of the ridging toward
Southcentral Alaska through the weekend. There is decent agreement
with the models on the overall pattern but there is inconsistency
with the timing and exact location of the various waves moving
through.

Friday night into Saturday there has been good consistency amongst
the models with a North Pacific low moving toward the Western
Aleutians. The deterministic runs all have the low rapidly
deepening to around 950 mb. However, on Sunday, models diverge
heavily with what happens to the low leading to low confidence
moving into next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning: 131.
MARINE...Gale Warning: 119 125 351 352.

&&

SYNOPSIS AND MODEL DISCUSSION...JPW
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JR
LONG TERM...DK

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
123 PM AKST Tue Dec 5 2017

AKZ101-111-061230-
Anchorage-Matanuska Valley-
Including the cities of Anchorage, Eagle River, Indian, Eklutna,
Palmer, Wasilla, Sutton, and Chickaloon
123 PM AKST Tue Dec 5 2017

...Update to Potential for moderate to heavy snow through
Wednesday morning...

There is potential for moderate to heavy snow to develop late
tonight across the Anchorage Bowl and Matanuska Valley, however
this system is not expected to bring accumulations as high as
previously forecast. Precipitation may start as rain or a wintry
mix before changing over to snow. Hazardous travel conditions
remain possible along area roadways through Wednesday.

As always, the latest forecast for your area can be found at
www.weather.gov/afc.