Small Craft Advisory 993, NWS Anchorage, AK

586 
FZAK52 PAFC 271245
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
345 AM AKST Wed Dec 27 2017

Coastal Waters Forecast for Southwest Alaska+Bristol Bay+The
Alaska Peninsula Waters and the Aleutian Islands up to 100 nm out.

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.

PKZ199-280115-
345 AM AKST Wed Dec 27 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
High pressure remains over the Bering and Aleutians through Fri
morning. A 987 mb North Pacific low 630 nm Southwest of Attu 
extends a front South of the Aleutians. A 971 mb low forms 90 nm 
South of Amchitka Thu afternoon and moves along the front to 80 nm
Southwest of Buldir Island at 966 mb by Fri morning. The front 
slides over the Aleutians for Fri morning.

$$

PKZ150-280115-
South of the AK Peninsula Sitkinak to Castle Cape-
345 AM AKST Wed Dec 27 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NE wind 25 kt. Seas 14 ft.
.TONIGHT...NE wind 20 kt. Seas 11 ft.
.THU...NE wind 15 kt. Seas 9 ft.
.THU NIGHT...NE wind 15 kt. Seas 7 ft.
.FRI...SE wind 40 kt. Seas 15 ft.
.SAT...SE wind 40 kt. Seas 22 ft.
.SUN...SE wind 30 kt. Seas 15 ft.

$$

PKZ155-280115-
South of the AK Peninsula Castle Cape to Cape Sarichef-
345 AM AKST Wed Dec 27 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NE wind 25 kt. Seas 16 ft.
.TONIGHT...NE wind 20 kt. Seas 14 ft.
.THU...NE wind 15 kt. Seas 9 ft.
.THU NIGHT...E wind 25 kt. Seas 7 ft.
.FRI THROUGH SAT...SE wind 40 kt. Seas 19 ft.
.SUN...SE wind 20 kt. Seas 13 ft.

$$

PKZ160-280115-
Bristol Bay-
345 AM AKST Wed Dec 27 2017

...HEAVY FREEZING SPRAY TONIGHT...

.TODAY...N wind 15 kt. Seas 4 ft. Freezing spray.
.TONIGHT...NE wind 20 kt. Seas 4 ft. Freezing spray...heavy near Kvichak
and Nushagak Bays.
.THU...NE wind 20 kt. Seas 3 ft. Freezing spray.
.THU NIGHT...NE wind 15 kt. Seas 3 ft.
.FRI...E wind 30 kt. Seas 8 ft.
.SAT...E wind 35 kt. Seas 9 ft.
.SUN...E wind 30 kt. Seas 6 ft.

$$

PKZ165-280115-
Port Heiden to Cape Sarichef-
345 AM AKST Wed Dec 27 2017

.TODAY...NE wind 20 kt. Seas 6 ft.
.TONIGHT...NE wind 20 kt. Seas 5 ft.
.THU...NE wind 15 kt. Seas 4 ft.
.THU NIGHT...E wind 15 kt. Seas 4 ft.
.FRI THROUGH SAT...E wind 35 kt. Seas 11 ft.
.SUN...E wind 25 kt. Seas 6 ft.

$$

PKZ170-280115-
Cape Sarichef to Nikolski Bering Side-
345 AM AKST Wed Dec 27 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NE wind 25 kt. Seas 8 ft.
.TONIGHT...NE wind 25 kt. Seas 7 ft.
.THU...E wind 25 kt. Seas 6 ft.
.THU NIGHT...E wind 30 kt. Seas 7 ft.
.FRI...E wind 40 kt. Seas 13 ft.
.SAT...NE wind 35 kt. Seas 13 ft.
.SUN...NE wind 20 kt. Seas 8 ft.

$$

PKZ171-280115-
Unalaska Bay-
345 AM AKST Wed Dec 27 2017

.TODAY...NE wind 15 kt. Seas 5 ft.
.TONIGHT...NE wind 15 kt diminishing to 10 kt after midnight. Seas
5 ft subsiding to 3 ft after midnight.
.THU...E wind 10 kt increasing to 15 kt in the afternoon. Seas 2
ft.
.THU NIGHT...SE wind 25 kt. Seas 3 ft.
.FRI...E wind 35 kt. Seas 5 ft.
.SAT...NE wind 15 kt. Seas 2 ft.
.SUN...E wind 15 kt. Seas 3 ft.

$$

PKZ172-280115-
Cape Sarichef to Nikolski Pacific Side-
345 AM AKST Wed Dec 27 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TODAY...NE wind 25 kt diminishing to 15 kt in the afternoon. Seas 
15 ft.
.TONIGHT...NE wind 15 kt. Seas 15 ft.
.THU...E wind 25 kt. Seas 12 ft.
.THU NIGHT...E wind 30 kt. Seas 14 ft.
.FRI...E wind 40 kt. Seas 22 ft.
.SAT...SW wind 30 kt. Seas 18 ft.
.SUN...SE wind 20 kt. Seas 14 ft.

$$

PKZ173-280115-
Nikloski to Seguam Island Bering Side-
345 AM AKST Wed Dec 27 2017

...GALE WARNING THURSDAY...

.TODAY...E wind increasing to 30 kt. Seas 9 ft. Rain showers and 
snow showers.
.TONIGHT...E wind 25 kt. Seas 8 ft.
.THU...E wind increasing to 35 kt. Seas 12 ft.
.THU NIGHT...E wind 35 kt. Seas 15 ft.
.FRI...NE wind 35 kt. Seas 17 ft.
.SAT...N wind 20 kt. Seas 16 ft.
.SUN...N wind 20 kt. Seas 10 ft.

$$

PKZ174-280115-
Nikolski to Seguam Island Pacific Side-
345 AM AKST Wed Dec 27 2017

...GALE WARNING THURSDAY...

.TODAY...E wind increasing to 25 kt. Seas 13 ft. Rain showers and 
snow showers.
.TONIGHT...E wind 25 kt. Seas 15 ft.
.THU...E wind 30 kt becoming SE 40 kt in the afternoon. Seas 18
ft.
.THU NIGHT...E wind 40 kt. Seas 20 ft.
.FRI...NE wind 35 kt. Seas 20 ft.
.SAT...W wind 20 kt. Seas 17 ft.
.SUN...N wind 25 kt. Seas 15 ft.

$$

PKZ175-280115-
Seguam Island to Adak Bering Side-
345 AM AKST Wed Dec 27 2017

...GALE WARNING THURSDAY...

.TODAY...E wind increasing to 25 kt. Seas 7 ft. Rain showers.
.TONIGHT...E wind 30 kt. Seas 13 ft. Rain showers and snow
showers.
.THU...E wind 40 kt. Seas 19 ft.
.THU NIGHT...E wind 45 kt. Seas 20 ft.
.FRI...NE wind 35 kt. Seas 16 ft.
.SAT...N wind 20 kt. Seas 16 ft.
.SUN...N wind 20 kt. Seas 12 ft.

$$

PKZ176-280115-
Seguam Island to Adak Pacific Side-
345 AM AKST Wed Dec 27 2017

...GALE WARNING THURSDAY...

.TODAY...E wind 20 kt. Seas 10 ft.
.TONIGHT...E wind 20 kt increasing to 30 kt after midnight. Seas
16 ft.
.THU...E wind 45 kt. Seas 21 ft building to 27 ft in the
afternoon. Rain.
.THU NIGHT...SE wind 40 kt. Seas 25 ft.
.FRI...NW wind 25 kt. Seas 19 ft.
.SAT...NW wind 20 kt. Seas 16 ft.
.SUN...N wind 25 kt. Seas 15 ft.

$$

PKZ177-280115-
Adak to Kiska-
345 AM AKST Wed Dec 27 2017

...STORM WARNING THURSDAY...

.TODAY...E wind increasing to 30 kt. Seas 14 ft.
.TONIGHT...E wind 40 kt. Seas 18 ft.
.THU...E wind 50 kt. Seas 23 ft building to 29 ft in the
afternoon. Rain with snow.
.THU NIGHT...SE wind 50 kt. Seas 26 ft.
.FRI...W wind 25 kt. Seas 19 ft.
.SAT THROUGH SUN...N wind 25 kt. Seas 17 ft.

$$

PKZ178-280115-
Kiska to Attu-
345 AM AKST Wed Dec 27 2017

...GALE WARNING THROUGH THURSDAY...

.TODAY...E wind 40 kt. Seas 24 ft.
.TONIGHT...E wind 45 kt. Seas 23 ft.
.THU...E wind 45 kt. Seas 28 ft. Snow and rain.
.THU NIGHT...NE wind 50 kt. Seas 32 ft.
.FRI...E wind 45 kt. Seas 29 ft.
.SAT...NE wind 35 kt. Seas 22 ft.
.SUN...N wind 30 kt. Seas 18 ft.

$$

PKZ179-280115-
Pribilof Islands Near Shore Waters-
345 AM AKST Wed Dec 27 2017

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...NE wind 20 kt. Seas 5 ft.
.TONIGHT...NE wind 20 kt. Seas 6 ft.
.THU...E wind 25 kt. Seas 6 ft.
.THU NIGHT...E wind 25 kt. Seas 7 ft.
.FRI THROUGH SAT...NE wind 35 kt. Seas 16 ft.
.SUN...NE wind 25 kt. Seas 10 ft.

$$

PKZ180-280115-
Kuskokwim Delta and Etolin Strait-
345 AM AKST Wed Dec 27 2017

...HEAVY FREEZING SPRAY TONIGHT...

.TODAY...N wind 20 kt. Seas 5 ft. Freezing spray.
.TONIGHT...N wind 20 kt. Seas 5 ft. Heavy freezing spray near the
coast.
.THU...NE wind 20 kt. Seas 5 ft. Freezing spray.
.THU NIGHT...NE wind 20 kt. Seas 4 ft.
.FRI...E wind 30 kt. Seas 10 ft.
.SAT...E wind 40 kt. Seas 13 ft.
.SUN...E wind 30 kt. Seas 8 ft.

$$

PKZ181-280115-
North and West of Nunivak Island-
345 AM AKST Wed Dec 27 2017

.TODAY...NE wind 15 kt. Seas 3 ft. Freezing spray.
.TONIGHT...NE wind 20 kt. Seas 4 ft. Freezing spray.
.THU...NE wind 15 kt. Seas 4 ft. Freezing spray.
.THU NIGHT...NE wind 15 kt. Seas 4 ft.
.FRI...NE wind 30 kt. Seas 7 ft.
.SAT...NE wind 35 kt. Seas 9 ft.
.SUN...NE wind 30 kt. Seas 8 ft.

$$

PKZ185-280115-
Saint Matthew Island Waters-
345 AM AKST Wed Dec 27 2017

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...NE wind 20 kt. Seas 6 ft. Freezing spray.
.TONIGHT...NE wind 20 kt. Seas 7 ft. Freezing spray.
.THU...NE wind 25 kt. Seas 7 ft. Freezing spray.
.THU NIGHT...NE wind 30 kt. Seas 10 ft.
.FRI...NE wind 30 kt. Seas 13 ft.
.SAT THROUGH SUN...NE wind 35 kt. Seas 16 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
458 AM AKST Tue Dec 26 2017

.ANALYSIS AND UPPER LEVELS...
Overall, a pretty quiet pattern has settled in over the southern
half of Alaska as an upper level long wave trough/ridge couplet
occupies the western/eastern halves of the state, respectively.
Mostly clear skies have formed over southcentral tonight as high
pressure builds in from both the south and the north. Weak
northerly outflow winds are already appearing at locations across
the Gulf Coast, which should pick up during the day as high
pressure continues to build in. Over the Western Aleutians/Bering,
an upper level ridge is building in as a low pressure system tries
to make its way in to the area, with a pronounced cirrus shield
moving in aloft.

&&

.MODEL DISCUSSION...
Models are in good agreement regarding the overall synoptic
pattern. The hi-res models are of course handling the local
effect outflow winds along the Gulf Coast the best and will be
utilized heavily in the morning forecast package.

&&

.AVIATION...
PANC...Generally light winds and VFR conditions will prevail
today, though some patchy low stratus may develop this morning
over the Anchorage Bowl. There is an increasing chance of more
widespread fog/low stratus developing tonight/tomorrow morning as
an upper level ridge axis moves overhead.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The weather pattern remains relatively tranquil over the next 48
hours, as high pressure currently centered over southeastern
portions of the Gulf relocates northwestward, taking up residence
near the mouth of the Copper River Delta by Wednesday. Increasing
heights/subsidence and warming temps aloft will strengthen the
inversion (wedge of warmer air). This will allow for some fog to
develop across portions of the Cook Inlet, including locations
near the Anchorage Bowl and lower Susitna River, and the interior
Copper River Basin through Thursday morning.

Otherwise, the main item of interest will be a developing offshore
flow. With light winds in place and cold air solidly entrenched
north of the coastal ranges, the pressure gradient will tighten
due to increased baroclinicity (temperature difference) between
the warmer Gulf waters and the snow-capped mountains. This will
in turn allow for cold air drainage to increase through the area
fjords and passes, with some gusty winds expected.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
As the pattern transitions from trough to ridge, lingering
moisture will promote widespread cloud cover early today which
should slowly erode by late this evening into the overnight hours.
Otherwise a transition to a colder air mass will begin tonight
with temperatures dropping into the single digits and teens across
most areas with each night/day this week getting progressively a
little colder. Variable winds tonight will turn from the north for
the remainder of the week.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Several weak disturbances spin over the Bering, bringing at least
a chance for snow showers today. The pattern begins to shift as a
low pressure system and front take shape in the northwest Pacific.
Part of a north Pacific front will swing northwestward and bring
Unalaska a period of accumulating snow today before quickly
shifting west and dissipating. A stronger system will affect the
western and central Bering Sea with a gale-force front on Thursday
along with rain and snow.

&&

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

The upper level low in the Arctic is still slated to dig into
western Alaska by mid-week and become nearly stationary somewhere
in the Norton Sound area for the second half of the week. Upper
level high pressure will persist over the Yukon during this time
frame as well with the storm track remaining well south of the
state. What all this means for the weather is that temperatures
will drop down to near normal or a little cooler than normal over
most of southern mainland Alaska with periods of clear skies.

The Aleutians will see some snow or rain/snow showers as some
weak lows track through that region, but the main storm track
where the strong storms will go is south of there.

This pattern is likely to change during the weekend as the upper
level low weakens and we get into a more southerly push aloft.
This will brig in more mild temperatures as the storm track heads
closer to southern Alaska.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale Warning 178 411.

&&

SYNOPSIS AND MODEL DISCUSSION...KVP
SOUTHCENTRAL ALASKA...PD/SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ML
LONG TERM...EZ