Storm Warning 104, NWS Anchorage, AK

427 
FZAK62 PAFC 211136
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
336 AM AKDT Wed Oct 21 2020

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-220130-
336 AM AKDT Wed Oct 21 2020
.SYNOPSIS FOR CENTRAL BERING SEA...

A 998 mb low at 47N 170W and a 987 mb low at 49N 176E merge near
50N 178W at 978 mb by Thu morning and then moves to 53N 173W at
977 mb by Fri morning.

$$

PKZ411-220130-
Bering Sea Offshore West of 180 and East of the International
Dateline-
336 AM AKDT Wed Oct 21 2020

...GALE WARNING THROUGH THURSDAY...

.TODAY...E wind 25 to 40 kt. Seas 11 to 16 ft.
.TONIGHT...NE wind 30 to 45 kt. Seas 13 to 21 ft.
.THU...N wind 30 to 45 kt. Seas 18 to 27 ft. Rain.
.THU NIGHT...N wind 25 to 40 kt. Seas 18 to 26 ft.
.FRI THROUGH SAT...NW wind 25 to 40 kt. Seas 12 to 20 ft.
.SUN...NW wind 10 to 20 kt. Seas 7 ft.

$$

PKZ412-220130-
Bering Sea Offshore 171W to 180 and North of 56N-
336 AM AKDT Wed Oct 21 2020

...STORM WARNING TONIGHT AND THURSDAY...

.TODAY...E wind 25 to 40 kt. Seas 9 to 14 ft.
.TONIGHT...NE wind 35 to 50 kt. Seas 15 to 23 ft. Rain.
.THU...E wind 35 to 50 kt. Seas 16 to 27 ft. Rain.
.THU NIGHT...E wind 25 to 40 kt. Seas 14 to 22 ft.
.FRI THROUGH SAT...N wind 15 to 30 kt. Seas 8 to 16 ft.
.SUN...NW wind 20 kt. Seas 6 ft.

$$

PKZ413-220130-
Bering Sea Offshore 171W to 180 and South of 56N-
336 AM AKDT Wed Oct 21 2020

...GALE WARNING THROUGH THURSDAY...

.TODAY...E wind 30 to 40 kt. Seas 10 to 17 ft. Rain.
.TONIGHT...E wind 30 to 45 kt. Seas 17 to 25 ft. Rain.
.THU...E wind 30 to 45 kt diminishing to 15 to 25 kt in the
afternoon. Seas 16 to 24 ft. Rain.
.THU NIGHT...NE wind 15 to 30 kt. Seas 11 to 17 ft.
.FRI THROUGH SUN...W wind 15 to 30 kt. Seas 9 to 14 ft.

$$

PKZ414-220130-
Bering Sea Offshore East of 171W-
336 AM AKDT Wed Oct 21 2020

...STORM WARNING TONIGHT...

.TODAY...E wind 25 to 35 kt increasing to 30 to 45 kt in the
afternoon. Seas 8 to 13 ft.
.TONIGHT...E wind 35 to 50 kt. Seas 14 to 22 ft. Rain.
.THU...SE wind 30 to 45 kt. Seas 13 to 21 ft. Rain.
.THU NIGHT...SE wind 15 to 30 kt. Seas 9 to 14 ft.
.FRI THROUGH SAT...SE wind 15 to 30 kt. Seas 8 to 13 ft.
.SUN...SW wind 10 to 20 kt. Seas 4 to 8 ft.

$$

643 
FZAK62 PAFC 212344
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
344 PM AKDT Wed Oct 21 2020

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-221330-
344 PM AKDT Wed Oct 21 2020

.SYNOPSIS FOR CENTRAL BERING SEA...

A 990 mb low at 50N 172W and a 974 mb low at 48N 175E merge near 
51N 172W at 974 mb Thu afternoon, then moves to 56N 170W at 984 mb 
Fri afternoon.

$$

PKZ411-221330-
Bering Sea Offshore West of 180 and East of the International
Dateline-
344 PM AKDT Wed Oct 21 2020

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...NE wind 30 to 45 kt. Seas 13 to 21 ft.
.THU...N wind 30 to 45 kt. Seas 18 to 27 ft.
.THU NIGHT...N wind 25 to 40 kt. Seas 18 to 26 ft. Rain.
.FRI...N wind 25 to 40 kt. Seas 18 to 21 ft.
.FRI NIGHT...N wind 20 to 35 kt. Seas 13 to 20 ft.
.SAT THROUGH MON...N wind 15 to 30 kt. Seas 9 to 14 ft.

$$

PKZ412-221330-
Bering Sea Offshore 171W to 180 and North of 56N-
344 PM AKDT Wed Oct 21 2020

...STORM WARNING THROUGH THURSDAY...

.TONIGHT...NE wind 35 to 50 kt. Seas 15 to 23 ft.
.THU...E wind 35 to 50 kt. Seas 16 to 27 ft. Rain.
.THU NIGHT...E wind 25 to 40 kt. Seas 13 to 21 ft. Rain.
.FRI...NE wind 15 to 30 kt. Seas 11 to 19 ft.
.FRI NIGHT...N wind 15 to 30 kt. Seas 8 to 16 ft.
.SAT...N wind 15 to 30 kt. Seas 8 to 13 ft.
.SUN THROUGH MON...N wind 20 kt. Seas 5 to 8 ft.

$$

PKZ413-221330-
Bering Sea Offshore 171W to 180 and South of 56N-
344 PM AKDT Wed Oct 21 2020

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...E wind 30 to 45 kt. Seas 17 to 25 ft. Rain.
.THU...E wind 30 to 45 kt diminishing to 15 to 25 kt in the
afternoon. Seas 16 to 24 ft. Rain.
.THU NIGHT...NE wind 20 to 35 kt. Seas 11 to 17 ft.
.FRI...N wind 15 to 30 kt. Seas 10 to 15 ft.
.FRI NIGHT...NW wind 15 to 30 kt. Seas 9 to 14 ft.
.SAT THROUGH SUN...W wind 15 to 30 kt. Seas 8 to 13 ft.
.MON...N wind 10 kt. Seas 6 ft.

$$

PKZ414-221330-
Bering Sea Offshore East of 171W-
344 PM AKDT Wed Oct 21 2020

...STORM WARNING TONIGHT...

.TONIGHT...E wind 35 to 50 kt. Seas 14 to 22 ft. Rain.
.THU...SE wind 30 to 45 kt. Seas 13 to 21 ft. Rain.
.THU NIGHT...SE wind 20 to 35 kt. Seas 8 to 16 ft.
.FRI...SE wind 20 to 35 kt. Seas 8 to 13 ft.
.FRI NIGHT...S wind 20 to 30 kt. Seas 9 to 13 ft.
.SAT...SE wind 15 to 30 kt. Seas 6 to 11 ft.
.SUN...SW wind 10 to 20 kt. Seas 4 to 8 ft.
.MON...W wind 15 kt. Seas 5 ft.

$$

556 
FZAK62 PAFC 221148
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
348 AM AKDT Thu Oct 22 2020

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-230115-
348 AM AKDT Thu Oct 22 2020
.SYNOPSIS FOR CENTRAL BERING SEA...

A 980 mb complex low near 50N 179W moves to 52N 173W at 981 mb by
Fri morning and then moves to 56N 172W at 990 mb by Sat morning.

$$

PKZ411-230115-
Bering Sea Offshore West of 180 and East of the International
Dateline-
348 AM AKDT Thu Oct 22 2020

...GALE WARNING THROUGH FRIDAY...

.TODAY...NE wind 35 to 45 kt. Seas 18 to 25 ft.
.TONIGHT...N wind 30 to 40 kt. Seas 20 to 24 ft. Rain.
.FRI...N wind 30 to 40 kt. Seas 19 to 22 ft.
.FRI NIGHT...N wind 20 to 35 kt. Seas 13 to 21 ft.
.SAT THROUGH MON...NE wind 15 to 30 kt. Seas 8 to 13 ft.

$$

PKZ412-230115-
Bering Sea Offshore 171W to 180 and North of 56N-
348 AM AKDT Thu Oct 22 2020

...GALE WARNING THROUGH FRIDAY...

.TODAY...NE wind 30 to 45 kt. Seas 19 to 25 ft. Rain.
.TONIGHT...NE wind 25 to 40 kt. Seas 14 to 22 ft. Rain.
.FRI...NE wind 20 to 35 kt. Seas 11 to 19 ft.
.FRI NIGHT...NE wind 15 to 30 kt. Seas 9 to 15 ft.
.SAT THROUGH MON...NW wind 15 to 30 kt. Seas 7 to 12 ft.

$$

PKZ413-230115-
Bering Sea Offshore 171W to 180 and South of 56N-
348 AM AKDT Thu Oct 22 2020

...GALE WARNING TODAY...

.TODAY...E wind 30 to 45 kt diminishing to 15 to 30 kt in the
afternoon. Seas 16 to 24 ft. Rain.
.TONIGHT...NE wind 15 to 30 kt. Seas 12 to 18 ft.
.FRI...N wind 15 to 30 kt. Seas 9 to 17 ft.
.FRI NIGHT...NW wind 15 to 30 kt. Seas 9 to 14 ft.
.SAT THROUGH SUN...W wind 15 to 30 kt. Seas 7 to 12 ft.
.MON...N wind 10 kt. Seas 6 ft.

$$

PKZ414-230115-
Bering Sea Offshore East of 171W-
348 AM AKDT Thu Oct 22 2020

...GALE WARNING THROUGH TONIGHT...

.TODAY...SE wind 30 to 45 kt. Seas 13 to 20 ft. Rain.
.TONIGHT...SE wind 20 to 35 kt. Seas 10 to 18 ft subsiding to 9 to
12 ft after midnight.
.FRI...SE wind 20 to 30 kt. Seas 8 to 12 ft. Rain showers.
.FRI NIGHT...SE wind 20 to 30 kt. Seas 8 to 12 ft.
.SAT...S wind 10 to 25 kt. Seas 5 to 10 ft.
.SUN...SW wind up to 15 kt. Seas 4 to 8 ft.
.MON...W wind 15 kt. Seas 5 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
431 AM AKDT Tue Oct 20 2020

.ANALYSIS AND UPPER LEVELS...

Lingering snow showers remain around the Copper River Basin this
morning as a broad upper level low continues to exit into the
Gulf. Behind this feature, ridging is starting to build in over
the Southwest coast, allowing fog and low stratus across the
Kuskokwim Delta to spread eastward into the Kuskokwim Valley for
this morning. A tight pressure gradient between these features is
allowing for strong outflow winds south of the Alaska Peninsula
and the North Gulf Coast.

Upper level ridging continues across the central and eastern
Bering and Aleutians, keeping relatively quiet weather conditions.
Farther west, a digging trough over the western Bering is helping
to amplify this ridge pattern. A low in the North Pacific
positioned south of Dutch Harbor this morning will be the next
significant weather maker to keep an eye on over the next several
days as it lifts northward into the forecast area.

&&

.MODEL DISCUSSION...

Run to run model consistency continues for the two lows developing
south of the Alaska Peninsula and Aleutian Chain Tuesday through
Wednesday, keeping higher confidence of storm force winds over the
eastern Bering on Wednesday. There is, however, a bit of
disagreement with the timing and how far north the associated
front lifts into Southwest Alaska starting on Thursday, which
impacts timing of precipitation that could make it into
Southcentral Alaska for Friday.

&&

.AVIATION...

PANC...VFR conditions and light winds persists. Low stratus
and/or fog could form early this morning for Anchorage and the
vicinity, which would improve by late morning.

&&

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

An upper short wave dropping south across the Eastern Mainland
will continue the chance of light snow across areas of the Copper
River Basin today. Light snow should end as drier air moves in
tonight.

An inverted surface trough over the Gulf waters in combination
with cooler air spilling in over Southcentral (predominately the
Copper River Basin/inland) will strengthen the thermal and
pressure gradients and give rise to brisk gap and outflow winds
across the North Gulf Coast and Eastern Kenai Peninsula. Winds in
these areas will likely peak overnight and diminish slowly
Wednesday as gradients relax some. Gusty winds which develop over
the Matanuska Valley tonight will likely linger into Wednesday
night. A weather front moving north on Wednesday brings gales and
increasing chances of rain to the Western Gulf/Kodiak Island late
Wednesday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Tuesday
morning through Thursday morning)...

High pressure will dominate the area today, with the fog and
stratus across the YK Delta this morning area clearing out by the
afternoon. Clear and colder temperatures move in Tuesday night,
but not expecting as much fog for Wednesday morning with drier air
moving in from the northeast and increasing winds. Wednesday will
be dry across the Southwest, however, an approaching frontal
system will bring increasing winds and moderate to heavy rain to
the AKPEN by Wednesday afternoon. This frontal system will slowly
move into the Bristol Bay region Wednesday night through Thursday
morning. This system will bring storm force winds over the water
and strong winds over the AKPEN and near coastal land areas of the
Southwest.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3: Tuesday
morning through Thursday morning)...

High pressure will continue across the region today with
increasing winds up to gale force Tuesday night into Wednesday
morning across the Aleutians as a frontal system moves north
towards the Aleutians. A complex low pressure system will push the
front northward on Wednesday with moderate to heavy rain across
the Aleutians and winds increasing to storm force across the
eastern Aleutians. These storm force winds will move into eastern
portions of the Bering Sea and Bristol Bay by Wednesday evening,
weakening by Thursday afternoon. As the low pressure pushes north
Thursday morning, winds will decrease across the central and
eastern Aleutians to small crafts, with areas of gales still
across much of the western Bering and Aleutians.

&&

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

Gulf of Alaska:

A well developed front moves across the Gulf through Sat. The
track and development vary considerably, but widespread easterly
gale force winds and waves will spread across the Gulf through
Sat. The area of gale force winds retreat to around Kodiak Island
Sat, leaving small craft winds over the Gulf slowly diminishing
through Sat.

Bering Sea:

A North Pacific low and front moves into the Central Bering
through Sat. Track and development of the system vary
considerably, but overall area coverage looks reasonable, with
easterly gale force winds and waves spreading into the Bering.
High end gale winds expected in Bristol Bay near Alaska Peninsula
channeled areas. The winds wrap the low bring a second round of
gale force winds across the Eastern Aleutians Fri. The entire
system slowly diminishes to small craft winds Sat.

&&

.LONG TERM FORECAST (Days 3 through 7: Thursday through
Monday)...

At the onset of the forecast period there is a ridge axis that
spans from the East Pacific across Kodiak and north of the Brooks
Range. Additionally, there is a robust low over the central
Aleutians. The leading edge of the precipitation shield will be at
the door step of Dillingham, King Salmon and Kipnuk. 48 hrs
later, the ridge axis is just east of Cordova and the upper level
low anchoring the aforementioned system is near the Pribilof
Islands. However, this pattern will result in broad southwest
flow over much of South Central and the precipitation shield will
have moved eastward. At this time, it is still too far out to
tell whether the front will bring any rain/snow to the Anchorage
area. The front will most definitely get sheared by the western
Alaska Range. Showers will linger over the Bering in association
with the remnants of the occlusion. In its wake, a new front will
emerge from the North Pacific. The precipitation shield will begin
to impact Attu Island and Shemya Saturday night.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Storms 150 155 172.
         Gales  127 128 130 138 160 165 170 171 173-180 411-414
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...ALH
SOUTHCENTRAL ALASKA...RMC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...RC
MARINE/LONG TERM...MK/PS