Small Craft Advisory 664, NWS Anchorage, AK

134 
FZAK52 PAFC 231153
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
353 AM AKDT Mon Aug 23 2021

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.

PKZ199-240115-
353 AM AKDT Mon Aug 23 2021
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 1012 mb low 190 nm north of Amchitka moves east and dissipates 
Mon afternoon. A 1001 mb low 20 nm south of Nunivak Island moves 
to 50 nm east of Cape Newenham at 1002 mb Tue morning and moves 
inland Tue evening and dissipates. A 1003 mb North Pacific low 
moves to 170 nm southwest of Unalaska at 1006 mb Wed morning. A 
1004 mb Kamchatka low moves to 140 nm north of Amchitka at 1002 
mb Wed morning.

$$

PKZ150-240115-
South of the AK Peninsula Sitkinak to Castle Cape-
353 AM AKDT Mon Aug 23 2021

.TODAY...W wind 20 kt. Seas 7 ft.
.TONIGHT...W wind 20 kt. Seas 7 ft.
.TUE...Variable wind 10 kt. Seas 5 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 5 ft.
.THU...Variable wind 10 kt. Seas 4 ft.
.FRI...N wind 15 kt. Seas 5 ft.

$$

PKZ155-240115-
South of the AK Peninsula Castle Cape to Cape Sarichef-
353 AM AKDT Mon Aug 23 2021

.TODAY...W wind 20 kt. Seas 7 ft.
.TONIGHT...SW wind 20 kt. Seas 6 ft.
.TUE...W wind 15 kt. Seas 4 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 5 ft.
.WED...SE wind 15 kt. Seas 5 ft.
.THU...NE wind 15 kt. Seas 5 ft.
.FRI...NW wind 20 kt. Seas 5 ft.

$$

PKZ160-240115-
Bristol Bay-
353 AM AKDT Mon Aug 23 2021

.TODAY...SW wind 20 kt. Seas 6 ft.
.TONIGHT...SW wind 20 kt. Seas 6 ft.
.TUE...SW wind 15 kt. Seas 5 ft.
.TUE NIGHT...W wind 15 kt. Seas 4 ft.
.WED THROUGH THU...W wind 10 kt. Seas 2 ft.
.FRI...NW wind 15 kt. Seas 2 ft.

$$

PKZ165-240115-
Port Heiden to Cape Sarichef-
353 AM AKDT Mon Aug 23 2021

...SMALL CRAFT ADVISORY TODAY...

.TODAY...W wind 25 kt. Seas 7 ft.
.TONIGHT...W wind 20 kt. Seas 7 ft.
.TUE...W wind 20 kt. Seas 6 ft.
.TUE NIGHT...W wind 15 kt. Seas 5 ft.
.WED THROUGH THU...N wind 15 kt. Seas 3 ft.
.FRI...NW wind 20 kt. Seas 4 ft.

$$

PKZ170-240115-
Cape Sarichef to Nikolski Bering Side-
353 AM AKDT Mon Aug 23 2021

.TODAY...W wind 20 kt. Seas 5 ft.
.TONIGHT...W wind 15 kt. Seas 5 ft.
.TUE...Variable wind 10 kt. Seas 4 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 3 ft.
.WED...NE wind 20 kt. Seas 3 ft.
.THU...N wind 20 kt. Seas 4 ft.
.FRI...W wind 15 kt. Seas 4 ft.

$$

PKZ171-240115-
Unalaska Bay-
353 AM AKDT Mon Aug 23 2021

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

$$

PKZ172-240115-
Cape Sarichef to Nikolski Pacific Side-
353 AM AKDT Mon Aug 23 2021

.TODAY...SW wind 20 kt. Seas 6 ft.
.TONIGHT...Variable wind 10 kt. Seas 5 ft.
.TUE...Variable wind 10 kt. Seas 5 ft.
.TUE NIGHT...SE wind 15 kt. Seas 5 ft.
.WED...E wind 15 kt. Seas 5 ft.
.THU...N wind 20 kt. Seas 6 ft.
.FRI...NW wind 20 kt. Seas 5 ft.

$$

PKZ173-240115-
Nikolski to Seguam Island Bering Side-
353 AM AKDT Mon Aug 23 2021

.TODAY...SW wind 15 kt. Seas 5 ft.
.TONIGHT...Variable wind 10 kt. Seas 4 ft.
.TUE...Variable wind 10 kt. Seas 4 ft.
.TUE NIGHT...E wind 15 kt. Seas 4 ft.
.WED...NE wind 20 kt. Seas 5 ft.
.THU...N wind 20 kt. Seas 6 ft.
.FRI...W wind 15 kt. Seas 4 ft.

$$

PKZ174-240115-
Nikolski to Seguam Island Pacific Side-
353 AM AKDT Mon Aug 23 2021

.TODAY...S wind 15 kt. Seas 4 ft.
.TONIGHT...Variable wind 10 kt. Seas 6 ft.
.TUE...Variable wind 10 kt. Seas 6 ft.
.TUE NIGHT...E wind 15 kt. Seas 5 ft.
.WED...N wind 15 kt. Seas 5 ft.
.THU...N wind 20 kt. Seas 6 ft.
.FRI...W wind 20 kt. Seas 5 ft.

$$

PKZ175-240115-
Seguam Island to Adak Bering Side-
353 AM AKDT Mon Aug 23 2021

.TODAY...Variable wind 10 kt. Seas 4 ft.
.TONIGHT...Variable wind 10 kt. Seas 3 ft.
.TUE...Variable wind 10 kt. Seas 3 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 2 ft.
.WED...NE wind 15 kt. Seas 4 ft.
.THU...NW wind 15 kt. Seas 4 ft.
.FRI...SW wind 15 kt. Seas 4 ft.

$$

PKZ176-240115-
Seguam Island to Adak Pacific Side-
353 AM AKDT Mon Aug 23 2021

.TODAY...E wind 15 kt. Seas 4 ft.
.TONIGHT...NE wind 15 kt. Seas 6 ft.
.TUE...E wind 10 kt. Seas 6 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 5 ft.
.WED...N wind 15 kt. Seas 5 ft.
.THU...NW wind 20 kt. Seas 6 ft.
.FRI...SW wind 15 kt. Seas 4 ft.

$$

PKZ177-240115-
Adak to Kiska-
353 AM AKDT Mon Aug 23 2021

.TODAY...NE wind 15 kt. Seas 4 ft.
.TONIGHT...NE wind 15 kt. Seas 6 ft.
.TUE...Variable wind 10 kt becoming W 20 kt in the afternoon. Seas
6 ft.
.TUE NIGHT...SW wind 20 kt. Seas 5 ft.
.WED...N wind 15 kt. Seas 7 ft.
.THU...W wind 15 kt. Seas 5 ft.
.FRI...S wind 20 kt. Seas 4 ft.

$$

PKZ178-240115-
Kiska to Attu-
353 AM AKDT Mon Aug 23 2021

.TODAY...Variable wind 10 kt. Seas 4 ft.
.TONIGHT...W wind 15 kt. Seas 4 ft.
.TUE...W wind 20 kt. Seas 5 ft.
.TUE NIGHT...NW wind 30 kt. Seas 10 ft.
.WED...N wind 25 kt. Seas 11 ft.
.THU...S wind 20 kt. Seas 5 ft.
.FRI...S wind 25 kt. Seas 6 ft.

$$

PKZ179-240115-
Pribilof Islands Near Shore Waters-
353 AM AKDT Mon Aug 23 2021

.TODAY...W wind 20 kt. Seas 6 ft.
.TONIGHT...W wind 15 kt. Seas 4 ft.
.TUE...Variable wind 10 kt. Seas 3 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 2 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.THU...W wind 15 kt. Seas 4 ft.
.FRI...SW wind 20 kt. Seas 5 ft.

$$

PKZ180-240115-
Kuskokwim Delta and Etolin Strait-
353 AM AKDT Mon Aug 23 2021

...SMALL CRAFT ADVISORY TODAY...

.TODAY...SW wind 25 kt. Seas 7 ft.
.TONIGHT...W wind 20 kt. Seas 7 ft.
.TUE...NW wind 20 kt. Seas 5 ft.
.TUE NIGHT...NW wind 15 kt. Seas 3 ft.
.WED...NW wind 10 kt. Seas 2 ft.
.THU...W wind 20 kt. Seas 3 ft.
.FRI...W wind 15 kt. Seas 3 ft.

$$

PKZ181-240115-
North and West of Nunivak Island-
353 AM AKDT Mon Aug 23 2021

.TODAY...N wind 20 kt. Seas 5 ft.
.TONIGHT...N wind 20 kt. Seas 4 ft.
.TUE...N wind 20 kt. Seas 4 ft.
.TUE NIGHT...N wind 20 kt. Seas 6 ft.
.WED...NW wind 20 kt. Seas 4 ft.
.THU...SW wind 25 kt. Seas 6 ft.
.FRI...NW wind 15 kt. Seas 5 ft.

$$

PKZ185-240115-
Saint Matthew Island Waters-
353 AM AKDT Mon Aug 23 2021

...SMALL CRAFT ADVISORY TODAY...

.TODAY...N wind 25 kt E of Saint Matthew Island...W 15 kt W of
Saint Matthew Island. Seas 5 ft.
.TONIGHT...W wind 20 kt. Seas 4 ft. Rain.
.TUE...NE wind 20 kt. Seas 6 ft.
.TUE NIGHT...NE wind 20 kt. Seas 6 ft.
.WED THROUGH THU...W wind 25 kt. Seas 7 ft.
.FRI...SE wind 20 kt. Seas 5 ft.

$$

176 
FZAK52 PAFC 232318
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
318 PM AKDT Mon Aug 23 2021

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.

PKZ199-241215-
318 PM AKDT Mon Aug 23 2021
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 1001 mb low 245 nm southwest of Kipnuk moves to 20 nm southeast
of Togiak at 1002 mb Tue morning and then inland Tue evening. A 
1008 mb North Pacific low 200 nm south of Nikolski enters in the 
Gulf at 1001 mb Tue afternoon. A 998 mb Kamchatka low moves to 35 
nm north of Kiska at 1003 mb Wed morning.

$$

PKZ150-241215-
South of the AK Peninsula Sitkinak to Castle Cape-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...W wind 20 kt. Seas 7 ft.
.TUE...W wind 10 kt. Seas 5 ft.
.TUE NIGHT...W wind 15 kt. Seas 4 ft.
.WED AND WED NIGHT...Variable wind 10 kt. Seas 5 ft.
.THU...Variable wind 10 kt. Seas 3 ft.
.FRI...N wind 15 kt. Seas 5 ft.
.SAT...W wind 20 kt. Seas 6 ft.

$$

PKZ155-241215-
South of the AK Peninsula Castle Cape to Cape Sarichef-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...SW wind 15 kt. Seas 6 ft.
.TUE...W wind 15 kt. Seas 4 ft.
.TUE NIGHT...W wind 15 kt. Seas 5 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.WED NIGHT...Variable wind 10 kt. Seas 4 ft.
.THU...NE wind 15 kt. Seas 4 ft.
.FRI THROUGH SAT...W wind 20 kt. Seas 5 ft.

$$

PKZ160-241215-
Bristol Bay-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...SW wind 20 kt. Seas 6 ft.
.TUE...SW wind 15 kt. Seas 5 ft.
.TUE NIGHT...W wind 15 kt. Seas 3 ft.
.WED...W wind 15 kt. Seas 3 ft.
.WED NIGHT...W wind 10 kt. Seas 2 ft.
.THU...W wind 10 kt. Seas 2 ft.
.FRI...NW wind 15 kt. Seas 2 ft.
.SAT...W wind 20 kt. Seas 4 ft.

$$

PKZ165-241215-
Port Heiden to Cape Sarichef-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...W wind 20 kt. Seas 7 ft.
.TUE...W wind 20 kt. Seas 5 ft.
.TUE NIGHT...W wind 15 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 3 ft.
.WED NIGHT...Variable wind 10 kt. Seas 2 ft.
.THU...N wind 15 kt. Seas 2 ft.
.FRI...NW wind 20 kt. Seas 4 ft.
.SAT...W wind 15 kt. Seas 4 ft.

$$

PKZ170-241215-
Cape Sarichef to Nikolski Bering Side-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...W wind 10 kt. Seas 4 ft.
.TUE...Variable wind 10 kt. Seas 3 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 3 ft.
.WED...Variable wind 10 kt. Seas 2 ft.
.WED NIGHT...NE wind 15 kt. Seas 3 ft.
.THU...N wind 15 kt. Seas 4 ft.
.FRI THROUGH SAT...SW wind 15 kt. Seas 4 ft.

$$

PKZ171-241215-
Unalaska Bay-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...W wind 10 kt. Seas 2 ft.
.TUE...Variable wind less than 10 kt. Seas 2 ft.
.TUE NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.WED AND WED NIGHT...E wind 10 kt. Seas 2 ft.
.THU...N wind 10 kt. Seas 3 ft.
.FRI...W wind 15 kt. Seas 3 ft.
.SAT...W wind 10 kt. Seas 2 ft.

$$

PKZ172-241215-
Cape Sarichef to Nikolski Pacific Side-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...Variable wind 10 kt. Seas 4 ft.
.TUE...Variable wind 10 kt. Seas 5 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 5 ft.
.WED AND WED NIGHT...E wind 15 kt. Seas 5 ft.
.THU...N wind 20 kt. Seas 5 ft.
.FRI...NW wind 20 kt. Seas 5 ft.
.SAT...W wind 15 kt. Seas 5 ft.

$$

PKZ173-241215-
Nikolski to Seguam Island Bering Side-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...Variable wind 10 kt. Seas 4 ft.
.TUE...Variable wind 10 kt. Seas 4 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 3 ft.
.WED NIGHT...NE wind 15 kt. Seas 4 ft.
.THU...N wind 15 kt. Seas 4 ft.
.FRI...W wind 15 kt. Seas 4 ft.
.SAT...S wind 20 kt. Seas 4 ft.

$$

PKZ174-241215-
Nikolski to Seguam Island Pacific Side-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...Variable wind 10 kt. Seas 5 ft.
.TUE...Variable wind 10 kt. Seas 6 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 5 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.WED NIGHT...NE wind 15 kt. Seas 4 ft.
.THU...N wind 20 kt. Seas 6 ft.
.FRI...W wind 20 kt. Seas 5 ft.
.SAT...SW wind 15 kt. Seas 4 ft.

$$

PKZ175-241215-
Seguam Island to Adak Bering Side-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...Variable wind 10 kt. Seas 3 ft.
.TUE...SW wind 10 kt. Seas 3 ft.
.TUE NIGHT...S wind 15 kt. Seas 3 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.WED NIGHT...Variable wind 10 kt. Seas 5 ft.
.THU...NW wind 15 kt. Seas 4 ft.
.FRI...SW wind 15 kt. Seas 4 ft.
.SAT...S wind 25 kt. Seas 4 ft.

$$

PKZ176-241215-
Seguam Island to Adak Pacific Side-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...E wind 10 kt. Seas 6 ft.
.TUE...E wind 10 kt. Seas 6 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 5 ft.
.WED NIGHT...Variable wind 10 kt. Seas 4 ft.
.THU...NW wind 20 kt. Seas 5 ft.
.FRI...SW wind 15 kt. Seas 4 ft.
.SAT...S wind 20 kt. Seas 5 ft.

$$

PKZ177-241215-
Adak to Kiska-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...Variable wind 10 kt. Seas 6 ft.
.TUE...Variable wind 10 kt becoming W 20 kt in the afternoon. Seas
5 ft.
.TUE NIGHT...SW wind 20 kt. Seas 5 ft. Rain.
.WED AND WED NIGHT...N wind 15 kt. Seas 8 ft.
.THU...W wind 15 kt. Seas 5 ft.
.FRI...S wind 20 kt. Seas 4 ft.
.SAT...S wind 25 kt. Seas 5 ft.

$$

PKZ178-241215-
Kiska to Attu-
318 PM AKDT Mon Aug 23 2021

...SMALL CRAFT ADVISORY TUESDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 4 ft.
.TUE...W wind 20 kt. Seas 6 ft. Rain.
.TUE NIGHT...NW wind 25 kt. Seas 6 ft building to 10 ft after
midnight.
.WED...N wind 25 kt. Seas 11 ft.
.WED NIGHT...NW wind 15 kt. Seas 8 ft.
.THU...S wind 20 kt. Seas 5 ft.
.FRI THROUGH SAT...SE wind 25 kt. Seas 8 ft.

$$

PKZ179-241215-
Pribilof Islands Near Shore Waters-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...NW wind 15 kt. Seas 4 ft.
.TUE...W wind 10 kt. Seas 3 ft.
.TUE NIGHT...Variable wind 10 kt. Seas 2 ft.
.WED...Variable wind 10 kt. Seas 3 ft.
.WED NIGHT...Variable wind 10 kt. Seas 3 ft.
.THU...W wind 15 kt. Seas 4 ft.
.FRI THROUGH SAT...SW wind 20 kt. Seas 5 ft.

$$

PKZ180-241215-
Kuskokwim Delta and Etolin Strait-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...W wind 20 kt. Seas 6 ft.
.TUE...NW wind 15 kt. Seas 5 ft.
.TUE NIGHT...NW wind 15 kt. Seas 3 ft.
.WED AND WED NIGHT...W wind 10 kt. Seas 2 ft.
.THU...W wind 20 kt. Seas 3 ft.
.FRI THROUGH SAT...W wind 15 kt. Seas 4 ft.

$$

PKZ181-241215-
North and West of Nunivak Island-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...N wind 20 kt. Seas 4 ft.
.TUE...N wind 15 kt. Seas 3 ft.
.TUE NIGHT...N wind 15 kt. Seas 5 ft.
.WED...N wind 15 kt. Seas 4 ft.
.WED NIGHT...W wind 20 kt. Seas 4 ft.
.THU...SW wind 20 kt. Seas 5 ft.
.FRI...NW wind 15 kt. Seas 5 ft.
.SAT...SW wind 20 kt. Seas 4 ft.

$$

PKZ185-241215-
Saint Matthew Island Waters-
318 PM AKDT Mon Aug 23 2021

.TONIGHT...W wind 20 kt. Seas 4 ft. Rain.
.TUE...E wind 20 kt. Seas 6 ft.
.TUE NIGHT...NE wind 20 kt. Seas 7 ft.
.WED...W wind 20 kt. Seas 5 ft.
.WED NIGHT...SW wind 25 kt. Seas 6 ft.
.THU...W wind 20 kt. Seas 5 ft.
.FRI...SE wind 20 kt. Seas 5 ft.
.SAT...S wind 25 kt. Seas 5 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
502 AM AKDT Sun Aug 22 2021

.ANALYSIS AND UPPER LEVELS...
An upper level ridge extends from the Gulf northeast towards the
southern tip of the Kenai Peninsula and towards the Kuskokwim
Delta. While several upper level lows are located across the
Bering and another low south of the AKPEN.

Satellite is showing mostly clear skies across Southcentral with
mid and high level clouds moving up from the south through Kodiak
Island and north towards the northern Kenai Peninsula. Out over
the Bering Satellite shows a front moving across the AKPEN and
eastern Bering with multiple surface lows. The first low is south
of Unalaska moving east which produced a few thunderstorms
earlier, but have since dissipated. While another low along the
front is east of St Paul Island, and two other lows, one over the
northern Bering and a weaker low north of Attu Island.

Surface observations show areas of fog and stratus across southern
portions of the AKPEN and around the Pribilof Islands. With radar
and observations showing rain across the Kuskokwim Delta, northern
AKPEN and near Bristol Bay. Across Southcentral temperatures have
dropped to the 30s and 40s as clear skies are allowing for cool
temperatures this morning.

Finally, the CIMSS MIMIC imagery is showing a good feed of
moisture from the Hawaii area into the AKPEN. In fact this
moisture brought 0.92 inches of rainfall to Cold Bay yesterday,
which was a record. Early next week this feed of moisture will
bring decent rainfall amounts to parts of Southcentral.

&&

.MODEL DISCUSSION...
Models are in good agreement with good forecast confidence through
the short term with the overall synoptic pattern. However, by
Monday and Tuesday the finer details of the low in the Gulf and
how much downsloping affects rain amounts across Anchorage, the
western Kenai Peninsula and the MAT valley remains uncertain.
Additionally, model uncertainty regarding the Turnagain winds
bending into west Anchorage Sunday afternoon and evening. Out
west fairly good model agreement with the lows and fronts with
some minor differences on the track of the low across the northern
and eastern Bering through Tuesday.

&&

.AVIATION...
PANC...VFR conditions and light winds will continue today. However
by the afternoon an upper level shortwave will bring light rain
and lowering ceilings to the airfield with Turnagain winds
developing between 4 pm and 10 pm.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 to 2:
Today through Tuesday)...

Clear and dry conditions will come to an end from west to east
today as an upper-level ridge moves to the Al-Can border in
advance of the next storm system to impact Southcentral.

This storm system is a complex feature with a double-barrel surface
low over the eastern Bering and an occluded front situated
along the Southwest Alaska between the two. The southernmost
surface low is extending a cold front across the western AKPen
and a warm front from Bristol Bay southeast over the western Gulf
south of Kodiak Island. This system is tapping into a tropical
moisture feed, with considerable moisture streaming north from
Hawaii, due to the highly amplified upper-level pattern. This
complex system will move northeast through the morning, with the
southernmost surface low lifting toward the Kuskokwim Delta by mid
morning. As it moves north, the warm front will move into
interior Southwest and lift across Cook Inlet and the Susitna
Valley. As the ridge retreats and the front moves through, a
strong southwesterly flow will develop with rain lifting from Cook
Inlet into the Susitna Valley. The southwest flow looks to
persist across this region, with rain continuing along the Alaska
Range and Cook Inlet north across the Mat-Su Valleys and Talkeetna
Mountains through early Monday. As this system moves toward
Southcentral, a coastal ridge will develop across Prince William
Sound. Southeasterly gap winds will increase in response to the
tightening pressure gradient, especially along Turnagain Arm, the
Knik River Valley, and Copper River Basin. Gusty southeasterly
winds may bend into Anchorage for a brief period of time Sunday
afternoon as the warm front and associated upper-level wave lift
north.

Farther south, the warm front will slow as it moves from Kodiak
Island to the Kenai Peninsula. The cold front will catch up to it,
with the front occluding just as a vigorous shortwave moves over
the western Gulf. The combination of these events will allow for
a triple-point low to develop just east of Kodiak City late
Sunday. This feature will deepen Sunday evening and lift a warm
front into the northern Gulf as the surface low and upper-level
trough begin to negatively tilt. The coastal ridge will
strengthen, with gap winds increasing. With lower pressure now
south of Anchorage, the Turnagain Arm wind will bend down the
inlet, bringing an abrupt end to any southerly winds for the
city. A southeasterly cross-barrier flow will also strengthen by
Sunday evening. The challenge to the precipitation forecast in the
short term is whether any pulses of energy embedded in the upper-
level flow and deep southerly fetch of moisture will be enough to
overcome any downsloping due to the cross-barrier flow. Thinking
here is that given the negative tilt in the upper-levels and
ridging extending back over the Chugach Mountains, any pulses of
energy in the upper-levels will be shifted west, allowing for
downsloping to win out, at least through Monday morning. With
downsloping likely in place from late Sunday evening through mid-
morning Monday, precipitation amounts for locations in the lee of
the Chugach and Kenai Mountains will be limited, at least
initially.

By mid-Monday, the upper-level flow becomes more southerly as the
trough lifts north. Energy out ahead of the main trough will move
over Cook Inlet and into the Susitna Valley, allowing rain to
once again develop across the western Kenai Peninsula, Anchorage
Bowl, and Matanuska Valley. This feature looks to also bring
another round of moderate rain into the Susitna Valley. The entire
trough lifts to the Southcentral coast by Monday evening with the
surface low lifting slowly toward Seward and its now occluded
front pushing over the coast. With everything lifting north, look
for widespread rain to develop over the Copper River Basin while
continuing elsewhere. The trough stalls over the region and
lingers through Tuesday as rain continues, especially along the
coast and across the Susitna Valley. A deformation band also
looks to set up west of the surface low, with the potential for an
area of moderate rain across the Kenai Peninsula through early
Tuesday afternoon. In total, one to two inches of rain is possible
along the Southcentral coast, with upwards of an inch of rain for
the Susitna Valley. Anywhere from half an inch to perhaps over an
inch of rain is possible along the western Kenai Peninsula, and
is dependent on whether that deformation band does come to
fruition. For Anchorage and the Matanuska Valley, totals will be
less, but a third to half an inch of rain is not out of the
question.

As for marine zones, easterly gales are expected to develop
tonight across the Barren islands as the surface low deepens. This
area of gales will extend east along the coast through Monday
night as the front lifts north. Northwesterly wind gusts are
likely across Kodiak Island by Monday evening in the wake of the
low.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...

A broad trough over the eastern Bering will gradually push inland
over Southwest AK through the early part of next week. This will
keep a rainy pattern in place for Southwest as multiple surface
lows spread precipitation inland. A leading front currently in
place over Southwest will continue to lift toward the northeast
throughout the day today. Expect showers to fill in on the
backside of this low, especially across the Bristol Bay area
through Monday as the low center moves from Nunivak Island into
Bristol Bay. By Tuesday, there will be breaks in precipitation,
especially across the Kuskokwim Delta area. Several weak upper
level waves will propagate over the Southwest coast leading to the
possibility for rain showers to continue through Wednesday.
Overall, anticipate a very wet pattern for Southwest through the
middle of the week.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...

Rain continues across the central and eastern Aleutians this
morning as a low pushes a front eastward. A broad longwave trough
is expected to remain in place over the Bering through the
forecast period, keeping a showery and cloudy pattern in place. As
several upper level waves move east over the mainland, a more
zonal pattern will setup across the Bering. A North Pacific low
will barely clip the western Aleutians Monday morning with rain as
it gets caught up in a jet streak and quickly moves into the
Gulf. By Tuesday, an upper level trough moves southward from
Siberia into the Bering. This system will introduce northerly
winds to the western Bering and will bring rain to the western
Aleutians late Tuesday.

&&

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

Expect winds less than 35 kts and seas less than 20 ft for the
Day 3 through 5 period for nearly all of the area. A weak low
moving over the central Bering Tuesday night may produce a small
area of gale force (35 kt +) winds that quickly tracks south over
the central and western Aleutians before dissipating.

&&

.LONG TERM FORECAST (Days 4 through 7: Wednesday through
Saturday)...

The long-term forecast starts out Wednesday on the quiet side
overall. A weak low in the Gulf and weak upper troughing may
produce disorganized showers through the day, keeping things
mainly cloudy over the southern Mainland. None of the shower
activity looks to be particularly heavy. Meanwhile a stronger
upper low over the Central Aleutians will slow down and pivot
eastward along the Eastern Aleutians Wednesday night. A large area
of ridging and high pressure moves into the Western Aleutians
behind this low.

On Thursday, as weak ridging builds into Southcentral, the
aforementioned low now south of the AKPEN will begin merging with
a polar trough digging southward across Northern Alaska. This will
allow for some rainfall to develop across Southwest Alaska between
these features. Meanwhile the ridging will continue building and
expanding westward across nearly all of the Bering by the end of
the day.

On Friday, the upper low moves into the Gulf as the northern
Alaska trough moves into the Susitna Valley. As a surface low
develops over the northern Gulf, rain is likely to break out
across much of Southcentral during the day. Depending on exactly
how these features interact, the rain could be heavy at times.
There remains some uncertainty in that regard. Up through this
point forecast confidence is above normal, as there is quite good
model agreement on the movement of these features. Ridging begins
to build into Southwest Alaska from the Bering, and the next low
may approach the far western Aleutians for the second half of the
day, but there is high uncertainty on the timing.

On Saturday, there is fairly good model agreement that the ridging
advances into at least all of Southwest Alaska, and possibly the
Cook Inlet region as well. This will depend on how quickly the low
and upper level troughing exits the area to the east, of which
there remains considerable uncertainty. There's a much higher
likelihood that by Saturday the next low and front pushes into the
Western Bering and Aleutians, causing active weather there.

Looking ahead with a large ridge moving into Southcentral,
conditions are looking favorable for a few day period of dry,
quiet, seasonable weather from Sunday right into early next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale warning 120 and 131.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...RC
SOUTHCENTRAL ALASKA...TM
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KO
MARINE/LONG TERM...JW