Small Craft Advisory 391, NWS Anchorage, AK

978 
FZAK51 PAFC 171135
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
335 AM AKDT Mon May 17 2021

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.

PKZ197-180045-
335 AM AKDT Mon May 17 2021
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

High pressure persists across the western Gulf through Tue
evening. A front approaches the western Gulf Tue night.

$$

PKZ119-180045-
Cape Suckling to Cape Cleare-
335 AM AKDT Mon May 17 2021

.TODAY...W wind 15 kt. Seas 5 ft.
.TONIGHT...W wind 15 kt. Seas 5 ft.
.TUE...SW wind 15 kt. Seas 4 ft.
.TUE NIGHT...SW wind 15 kt. Seas 4 ft.
.WED...S wind 15 kt. Seas 4 ft.
.THU THROUGH FRI...E wind 30 kt. Seas 13 ft.

$$

PKZ120-180045-
Cape Cleare to Gore Point-
335 AM AKDT Mon May 17 2021

...SMALL CRAFT ADVISORY TUESDAY...

.TODAY...SW wind 15 kt. Seas 4 ft.
.TONIGHT...W wind 20 kt. Seas 4 ft.
.TUE...SW wind 25 kt. Seas 5 ft.
.TUE NIGHT...SW wind 25 kt. Seas 4 ft.
.WED...SE wind 25 kt. Seas 6 ft.
.THU THROUGH FRI...E wind 30 kt. Seas 13 ft.

$$

PKZ121-180045-
Resurrection Bay-
335 AM AKDT Mon May 17 2021

.TODAY...Variable wind less than 10 kt becoming S 15 kt in the
afternoon. Seas 3 ft.
.TONIGHT...S wind 15 kt becoming N 10 kt after midnight. Seas 3 ft.
.TUE...Variable wind 10 kt becoming S 15 kt in the afternoon. Seas
3 ft.
.TUE NIGHT...S wind 15 kt. Seas 3 ft.
.WED...S wind 15 kt. Seas 3 ft.
.THU...S wind 10 kt. Seas 2 ft.
.FRI...N wind 10 kt. Seas 2 ft.

$$

PKZ125-180045-
Prince William Sound-
335 AM AKDT Mon May 17 2021

.TODAY...W wind 10 kt. Seas 2 ft.
.TONIGHT...SW wind 10 kt in the evening becoming variable less
than 10 kt. Seas 2 ft.
.TUE...Variable wind less than 10 kt. Seas 2 ft.
.TUE NIGHT...SE wind 10 kt. Seas 2 ft.
.WED...Variable wind less than 10 kt. Seas 2 ft.
.THU THROUGH FRI...E wind 20 kt. Seas 3 ft.

$$

PKZ126-180045-
Port Valdez-
335 AM AKDT Mon May 17 2021

.TODAY...Variable wind less than 10 kt becoming SW 15 kt in the
afternoon. Seas 3 ft.
.TONIGHT...SW wind 15 kt in the evening becoming variable less than
10 kt. Seas 3 ft.
.TUE...E wind 10 kt becoming SW 15 kt in the afternoon. Seas 3 ft.
.TUE NIGHT...W wind 15 kt. Seas 3 ft.
.WED THROUGH THU...SW wind 15 kt. Seas 3 ft.
.FRI...Variable wind 10 kt. Seas 2 ft.

$$

PKZ127-180045-
Valdez Narrows-
335 AM AKDT Mon May 17 2021

.TODAY...SW wind 10 kt increasing to 15 kt in the afternoon. Seas 3 
ft.
.TONIGHT...SW wind 15 kt becoming N 10 kt after midnight. Seas 3
ft.
.TUE...N wind 10 kt becoming SW 15 kt in the afternoon. Seas 3 ft.
.TUE NIGHT...Variable wind 15 kt. Seas 3 ft.
.WED...SW wind 15 kt. Seas 3 ft.
.THU THROUGH FRI...NE wind 15 kt. Seas 3 ft.

$$

PKZ128-180045-
Valdez Arm-
335 AM AKDT Mon May 17 2021

.TODAY...Variable wind less than 10 kt. Seas 2 ft.
.TONIGHT...Variable wind less than 10 kt becoming NE 10 kt after
midnight. Seas 2 ft.
.TUE...Variable wind less than 10 kt becoming SW 10 kt in the
afternoon. Seas 2 ft.
.TUE NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.WED...Variable wind 10 kt. Seas 2 ft.
.THU THROUGH FRI...NE wind 10 kt. Seas 2 ft.

$$

PKZ129-180045-
Passage Canal-
335 AM AKDT Mon May 17 2021

.TODAY...W wind 10 kt. Gusts to 20 kt near Whittier. Seas 2 ft.
.TONIGHT...W wind 15 kt. Gusts to 25 kt near Whittier. Seas 2 ft.
.TUE...W wind 10 kt in the morning becoming variable less than 10 
kt. Seas 2 ft.
.TUE NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.WED...Variable wind less than 10 kt. Seas 2 ft.
.THU...E wind 10 kt. Seas 2 ft.
.FRI...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ130-180045-
West of Barren Islands including Kamishak Bay-
335 AM AKDT Mon May 17 2021

.TODAY...W wind 15 kt. Seas 3 ft.
.TONIGHT...W wind 20 kt. Seas 5 ft.
.TUE...W wind 20 kt. Seas 5 ft.
.TUE NIGHT...SW wind 15 kt. Seas 4 ft.
.WED...SE wind 30 kt. Seas 8 ft.
.THU...E wind 35 kt. Seas 13 ft.
.FRI...E wind 30 kt. Seas 12 ft.

$$

PKZ131-180045-
Barren Islands East-
335 AM AKDT Mon May 17 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TODAY...SW wind 20 kt. Seas 4 ft.
.TONIGHT...W wind 25 kt. Seas 4 ft.
.TUE...W wind 20 kt. Seas 4 ft.
.TUE NIGHT...SW wind 15 kt. Seas 4 ft.
.WED...SE wind 30 kt. Seas 11 ft.
.THU...E wind 40 kt. Seas 15 ft.
.FRI...E wind 35 kt. Seas 13 ft.

$$

PKZ132-180045-
Marmot Island to Sitkinak-
335 AM AKDT Mon May 17 2021

.TODAY...SW wind 15 kt. Seas 6 ft.
.TONIGHT...W wind 20 kt. Seas 5 ft.
.TUE...W wind 20 kt. Seas 4 ft.
.TUE NIGHT...SW wind 20 kt. Seas 4 ft.
.WED THROUGH THU...E wind 30 kt. Seas 12 ft.
.FRI...SE wind 20 kt. Seas 11 ft.

$$

PKZ136-180045-
Chiniak Bay-
335 AM AKDT Mon May 17 2021

.TODAY...Variable wind less than 10 kt. Seas 2 ft.
.TONIGHT...Variable wind less than 10 kt. Seas 2 ft.
.TUE...Variable wind less than 10 kt. Seas 3 ft.
.TUE NIGHT...Variable wind less than 10 kt. Seas 3 ft.
.WED...SE wind 25 kt. Seas 9 ft.
.THU...E wind 25 kt. Seas 9 ft.
.FRI...SE wind 15 kt. Seas 4 ft.

$$

PKZ137-180045-
Marmot Bay-
335 AM AKDT Mon May 17 2021

.TODAY...Variable wind less than 10 kt becoming W 10 kt in the
afternoon. Seas 2 ft.
.TONIGHT...W wind 15 kt. Seas 3 ft.
.TUE...W wind 15 kt becoming SW 10 kt in the afternoon. Seas 3 ft.
.TUE NIGHT...W wind 10 kt. Seas 2 ft.
.WED THROUGH THU...E wind 25 kt. Seas 10 ft.
.FRI...E wind 15 kt. Seas 4 ft.

$$

PKZ138-180045-
Shelikof Strait-
335 AM AKDT Mon May 17 2021

.TODAY...SW wind 20 kt. Seas 5 ft.
.TONIGHT...SW wind 20 kt. Seas 5 ft.
.TUE...SW wind 20 kt. Seas 5 ft.
.TUE NIGHT...SW wind 20 kt. Seas 5 ft.
.WED...E wind 35 kt. Seas 10 ft.
.THU...NE wind 35 kt. Seas 13 ft.
.FRI...NE wind 25 kt. Seas 8 ft.

$$

PKZ139-180045-
Cook Inlet Kalgin Island to Point Bede-
335 AM AKDT Mon May 17 2021

.TODAY...S wind 10 kt in the morning becoming variable less than
10 kt. Seas 3 ft subsiding to 1 ft in the afternoon.
.TONIGHT...SW wind 20 kt. Seas 4 ft.
.TUE...SW wind 15 kt. Seas 4 ft.
.TUE NIGHT...SW wind 20 kt. Seas 5 ft.
.WED...S wind 15 kt. Seas 3 ft.
.THU THROUGH FRI...NE wind 20 kt. Seas 6 ft.

$$

PKZ140-180045-
Cook Inlet North of Kalgin Island-
335 AM AKDT Mon May 17 2021

.TODAY...Variable wind less than 10 kt. Seas 2 ft.
.TONIGHT...SW wind 10 kt. Seas 2 ft.
.TUE...Variable wind less than 10 kt becoming SW 10 kt in the
afternoon. Seas 3 ft.
.TUE NIGHT...SW wind 20 kt. Seas 5 ft.
.WED...S wind 15 kt. Seas 3 ft.
.THU THROUGH FRI...NE wind 15 kt. Seas 4 ft.

$$

PKZ141-180045-
Kachemak Bay-
335 AM AKDT Mon May 17 2021

.TODAY...Variable wind less than 10 kt becoming SW 15 kt in the
afternoon. Seas 2 ft building to 4 ft in the afternoon.
.TONIGHT...SW wind 10 kt. Seas 2 ft.
.TUE...SW wind 10 kt increasing to 20 kt in the afternoon. Seas 2
ft building to 4 ft in the afternoon.
.TUE NIGHT...S wind 15 kt. Seas 4 ft.
.WED...S wind 15 kt. Seas 4 ft.
.THU THROUGH FRI...NE wind 15 kt. Seas 3 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
426 AM AKDT Sun May 16 2021

.ANALYSIS AND UPPER LEVELS...

An upper level low was present to the southeast of Kodiak Island
this morning. Another upper level low is present to the southeast
of Dutch Harbor moving to the east. Generally northerly flow is
seen across much of the Bering with a third upper level low
present across the far northwest Bering Sea near east Russia.
Lastly, a fourth upper level low is present across the North Slope
with southern Mainland Alaska in between this low and the low
near Kodiak Island. At the surface, a low is seen moving towards
Prince William Sound which is bringing rain showers to Cordova,
Whittier, and the Valdez area. Besides the low near Prince William
Sound, much of the rest of Southcentral and Kodiak Island remains
quiet with partly to mostly cloudy conditions with an occasional
isolated shower and temperatures in the 40s with mid to upper 30s
in the Copper River Basin.

Southwest Alaska remains fairly quiet as well with offshore flow
leading to partly to mostly cloudy skies as well with a few
showers across the Middle Kuskokwim Valley. Temperatures area-wide
are generally in the 40s and the upper 30s. For the Aleutians and
the Bering Sea, much of the area remains quiet under weak
northerly flow and light winds with low stratus and fog for the
Pribilofs.

&&

.MODEL DISCUSSION...

Models are in great agreement on the synoptic scale features out
through Day 3. The main issues going into the forecast package
this morning are: local effect winds around Southcentral as well
as if a shower will make it off the Chugach Mountains and into the
Anchorage Bowl area later today. Out west, models are in general
good agreement as well with the main issue being how widespread
any shower activity will be across Bristol Bay and the Middle
Kuskokwim Valley and how much rainfall will result from it. Also,
instability is marginal, therefore, thunderstorms weren't included
in this forecast package. Across the Bering, the main issue is the
low stratus and fog and how expansive it will be due to high
pressure overhead.

&&

.AVIATION...
PANC...Mainly VFR conditions and light south to southwest winds
will persist for the TAF package. However, MVFR ceilings are
hovering around the terminal this morning, therefore, included a
TEMPO group in the TAF to account for this.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2: Today
through Monday Night)...

A mix of sun and clouds is expected for much of interior
Southcentral today. The front that brought the clouds, moisture,
and rain yesterday has fallen apart, leaving a moistened
atmosphere with weak winds. A surface low causing gusty conditions
early this morning in western Prince William Sound will move into
the Kenai Mountains south of Whittier today. This low should keep
the winds through Turnagain Arm much weaker today, as the
dominating flow becomes up-Inlet this afternoon. Elsewhere, sea
breezes will return today in the usual areas. Shower activity is
expected this afternoon, mainly across most of the mountains.
However, due to much weaker steering flow expected this afternoon,
the showers will remain nearly stationary or move very slowly.
Thus, most populated areas, except perhaps portions of the
Matanuska Valley, will remain dry today.

Ridging and associated warming temperatures in the upper levels on
Monday, along with westerly offshore flow, will effectively clear
out the atmosphere across Southcentral. The drier conditions, more
stable atmosphere, and subsidence will all work to make for a
gorgeous sunny day on Monday. The sunny skies will persist
throughout the day. Most areas will be several degrees warmer on
Monday as compared with today as well.

&&

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

A shortwave from the remnants of a low now south of the AKPen
moves across eastern Southwest, allowing for some lingering
showers across eastern Bristol Bay and the Kuskokwim Valley today
through the overnight hours. While most of the precipitation
should be confined to the mountains, some may spill into the lower
elevations at times. A high pressure ridge overtakes the
Kuskokwim Delta this afternoon. Clear and dry conditions filter
in from west to east as the ridge moves across the region.

&&

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

Light showers should start dying off this morning for the Eastern
Aleutians and the Southern AKPen as the remnants of a low pushes
south and dissipates. High pressure becomes the dominant force across
the Bering by this afternoon, keeping conditions dry and calm
through Tuesday. Light winds and waves are expected throughout the
forecast period. Flow ahead of the surface high will be northerly,
with southerly flow on the backside.

&&

.MARINE (Days 3 through 5: Tuesday through Thursday)...

High pressure with generally light winds across most of the
Bering through Thursday. A North Pacific low tracks just South of
the Aleutians for Thursday. Models in good agreement. The wind
wrapped North Pacific low brings small craft winds over the
Central Aleutians and Alaska Peninsula Wednesday, increasing to
gale force winds spreading into the Southern Bering Thursday. High
pressure moves across the Gulf. Gusty gap winds around Kodiak
Island Tuesday and Wed. Small craft winds with the approaching
low become gale force winds over the Western Gulf and Kodiak
Island Thursday. Seas to 12 feet south of Kodiak Island.

&&

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

Conditions will remain relatively quiet across the area for most
of this time period. The early part of the week will feature
weak flow over much of the mainland allowing for convection
along the mountains. Temperatures will continue to hold very close
to normal for mid-May. By next weekend, there are some signs of a
much more Summer-like pattern building over the state from the
east. Here are the details:

Tue and Wed, there will not be any dominant weather feature across
southern AK or the Aleutians. This will create partly cloudy
conditions for the mainland with afternoon showers possible each
day. As temperatures slowly warm in response to increasing
daylight/climatology, we could start to see some more thunderstorm
activity as we move towards the middle of the week. Any chance for
this will be centered along the thermal trough and near the
mountains. High temperatures will continue to hover in the mid 50s
to low 60s for locations further inland.

By Thu and Fri, a system dropping across the northwest Bering Sea
will phase with some energy over the North Pacific. The
interaction will be somewhere near the Central Aleutians and
result in a developing surface low. This system will bring a
return to wind and rain to the Eastern Aleutians and Alaska
Peninsula as it moves to the east. By Fri, this system will start
to bring rain back into Southwest AK and Kodiak Island. For
Southcentral, this low will struggle to make much progress inland
as a ridge of high pressure starts to build near the ALCAN border.
While there is still a moderate to high amount of uncertainty this
far out, there are indications that this ridge could start to
bring some of our warmest temperatures of the year thus far (850
mb/5000' at 10-15C). Generally this forecast leans on the EC and
GFS ensemble means to handle the uncertainty.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...MV
SOUTHCENTRAL ALASKA...JPW
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KM
MARINE/LONG TERM...KZ/MO