Storm Warning 76, NWS Anchorage, AK

909 
FZAK62 PAFC 061230 CCA
OFFALU

Offshore Waters Forecast...CORRECTED
National Weather Service Anchorage AK
330 AM AKST Wed Mar 6 2019

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.

PKZ499-070145-
330 AM AKST Wed Mar 6 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A 955 mb low at 51N 172E Wed morning moves to 54N 179E at 956 mb by 
Thu morning and then to 56N 176W at 972 mb by Fri morning. A front 
approaches the western Aleutians Fri morning associated with a 960
mb North Pacific low.

$$

PKZ411-070145-
Bering Sea Offshore West of 180 and East of the International
Dateline-
330 AM AKST Wed Mar 6 2019

...STORM WARNING TODAY...

.TODAY...E wind 35 to 50 kt. Seas 14 to 26 ft. Rain with snow.
.TONIGHT...NE wind 30 to 45 kt. Seas 19 to 25 ft. Rain.
.THU...N wind 20 to 35 kt. Seas 16 to 22 ft. Rain.
.THU NIGHT...N wind 15 to 30 kt. Seas 12 to 18 ft.
.FRI...NE wind 20 to 35 kt. Seas 10 to 16 ft.
.SAT...N wind 20 to 35 kt. Seas 12 to 19 ft.
.SUN...NW wind up to 20 kt. Seas 8 to 13 ft.

$$

PKZ412-070145-
Bering Sea Offshore 171W to 180 and North of 56N-
330 AM AKST Wed Mar 6 2019

...STORM WARNING TODAY...

.TODAY...E wind 35 to 50 kt. Seas 11 to 19 ft. Snow and rain.
.TONIGHT...E wind 25 to 40 kt becoming SE 20 to 30 kt after
midnight. Seas 16 to 22 ft.  Rain and snow.
.THU...E wind 20 to 30 kt. Seas 15 to 21 ft. Rain.
.THU NIGHT...E wind 15 to 30 kt. Seas 13 to 19 ft.
.FRI...E wind 20 to 35 kt. Seas 9 to 14 ft.
.SAT THROUGH SUN...NW wind 20 to 35 kt. Seas 10 to 18 ft.

$$

PKZ413-070145-
Bering Sea Offshore 171W to 180 and South of 56N-
330 AM AKST Wed Mar 6 2019

...GALE WARNING THROUGH THURSDAY...

.TODAY...SE wind 30 to 45 kt. Seas 13 to 21 ft. Snow and rain.
.TONIGHT...S wind 25 to 40 kt. Seas 15 to 25 ft. Rain.
.THU...S wind 20 to 35 kt. Seas 18 to 24 ft. Rain.
.THU NIGHT...SW wind 20 to 35 kt. Seas 14 to 22 ft.
.FRI...S wind 15 to 30 kt. Seas 9 to 17 ft.
.SAT THROUGH SUN...W wind 15 to 30 kt. Seas 11 to 19 ft.

$$

PKZ414-070145-
Bering Sea Offshore East of 171W-
330 AM AKST Wed Mar 6 2019

...GALE WARNING THROUGH TONIGHT...

.TODAY...SE wind 25 to 40 kt. Seas 8 to 13 ft. Rain.
.TONIGHT...SE wind 20 to 35 kt. Seas 8 to 16 ft. Snow with rain.
.THU...S wind 10 to 25 kt. Seas 8 to 16 ft. Rain.
.THU NIGHT...SE wind 10 to 25 kt. Seas 9 to 17 ft.
.FRI THROUGH SAT...S wind 20 to 35 kt. Seas 10 to 18 ft.
.SUN...W wind 20 to 35 kt. Seas 10 to 18 ft.

$$

323 
FZAK62 PAFC 070003
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
303 PM AKST Wed Mar 6 2019

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.

PKZ499-071400-
303 PM AKST Wed Mar 6 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A strong 954 mb low at 52N 176E moves to 58N 172W at 971 mb and 
dissipates Fri afternoon. Its front sweeps into Western Alaska for
Fri afternoon. A 958 mb low near 47N 170E Fri morning moves to 
50N 177E at 956 mb by Fri afternoon. Its front pushes over the 
Aleutians into the Bering through Fri afternoon.

$$

PKZ411-071400-
Bering Sea Offshore West of 180 and East of the International
Dateline-
303 PM AKST Wed Mar 6 2019

...GALE WARNING THROUGH THURSDAY...

.TONIGHT...NE wind 30 to 45 kt. Seas 19 to 25 ft. Rain.
.THU...N wind 20 to 35 kt. Seas 16 to 22 ft. Rain.
.THU NIGHT...N wind 15 to 30 kt. Seas 12 to 18 ft.
.FRI...NE wind 15 to 30 kt. Seas 11 to 15 ft.
.FRI NIGHT...N wind 20 to 35 kt. Seas 10 to 18 ft.
.SAT...N wind 20 to 35 kt. Seas 14 to 20 ft.
.SUN...NW wind up to 20 kt. Seas 8 to 13 ft.
.MON...NW wind 25 kt. Seas 8 to 11 ft.

$$

PKZ412-071400-
Bering Sea Offshore 171W to 180 and North of 56N-
303 PM AKST Wed Mar 6 2019

...GALE WARNING TONIGHT...

.TONIGHT...E wind 25 to 40 kt becoming SE 20 to 30 kt after
midnight. Seas 16 to 22 ft. Rain and snow.
.THU...E wind 20 to 30 kt. Seas 15 to 22 ft. Rain.
.THU NIGHT...E wind 15 to 30 kt. Seas 14 to 20 ft.
.FRI...E wind 15 to 30 kt. Seas 11 to 15 ft.
.FRI NIGHT...NE wind 20 to 35 kt. Seas 9 to 15 ft.
.SAT...N wind 20 to 35 kt. Seas 11 to 19 ft.
.SUN THROUGH MON...NW wind 20 to 30 kt. Seas 9 to 17 ft.

$$

PKZ413-071400-
Bering Sea Offshore 171W to 180 and South of 56N-
303 PM AKST Wed Mar 6 2019

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...S wind 25 to 40 kt. Seas 15 to 26 ft. Rain.
.THU...S wind 20 to 35 kt. Seas 18 to 25 ft. Rain showers.
.THU NIGHT...SW wind 20 to 35 kt. Seas 14 to 22 ft. Rain showers.
.FRI...S wind 15 to 30 kt. Seas 10 to 18 ft.
.FRI NIGHT...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.SAT THROUGH MON...NW wind 15 to 30 kt. Seas 11 to 19 ft.

$$

PKZ414-071400-
Bering Sea Offshore East of 171W-
303 PM AKST Wed Mar 6 2019

...GALE WARNING TONIGHT...

.TONIGHT...SE wind 20 to 35 kt. Seas 8 to 16 ft. Snow with rain.
.THU...S wind 10 to 25 kt. Seas 9 to 17 ft.
.THU NIGHT...SE wind 10 to 25 kt. Seas 9 to 17 ft. Rain showers.
.FRI...S wind 10 to 25 kt. Seas 10 to 18 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 12 to 15 ft.
.SAT...S wind 10 to 25 kt. Seas 9 to 14 ft.
.SUN THROUGH MON...NW wind 20 to 35 kt. Seas 10 to 18 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
509 PM AKST Tue Mar 5 2019

.ANALYSIS AND UPPER LEVELS...
The upper level pattern has a highly amplified ridge at 250 mb
near the Alcan border this afternoon. A sharp trough extends out
of the Bering Strait and through Bristol Bay as well creating a
jet streak of around 90 kt over Southwest mainland Alaska.
A strong surface low with a central pressure in the lower 960s is
southwest of Attu this afternoon. This low will move to near Attu
overnight and will be the main weather feature for the Bering Sea
region the next few days.

&&

.MODEL DISCUSSION...
There is not a lot of difference from what was mentioned on the
previous discussion about the models. Models are in good agreement
through the next few days with the NAM's higher resolution being
used for local effects near the terrain.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist.

&&

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

A moist, southerly flow out ahead of an eastward moving trough
over the AKPEN will continue to push clouds and areas of
mixed rain and snow from the western Gulf and Kodiak Island,
north across Cook Inlet and into the Susitna Valley. This trough
will trend weaker through the day Wednesday, with only pockets of
light precipitation lingering along the Kenai Peninsula, as it
moves slowly toward the northern Gulf. An upper-level vorticity
maximum moving across Southcentral Thursday will act to re-
strengthen this feature, bringing another round of coastal rain,
inland and higher elevation snow, and increasing southeasterly
gap winds (Passage Canal and Turnagain Arm). The southerly,
cross-barrier winds will help limit precipitation for locations
along the lee of the Kenai and Chugach Mountains. This system
will lift northeast by late Thursday, with perhaps a brief period
of snow showers for the Anchorage Bowl, and stall over Prince
William Sound. Behind it, a more vigorous shortwave will dive into
the western Gulf, with a surface low developing near Kodiak
Island. This system will strengthen as it moves toward the
eastern Kenai Peninsula Friday. A deep, southerly fetch with this
system will usher in more clouds and precipitation, as well as
strong southeasterly gap winds along favored coastal areas,
through the end of the week. Needless to say, with the departure
of the upper- level ridge, Southcentral Alaska is returning to a
more active and unsettled weather pattern for at least the next
few days.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2: Tonight
through Thursday afternoon)...

The remnants of a front remain parked over Southwest, bringing
continued precipitation across the Kuskokwim Valley and Bristol
Bay area. Precipitation will gradually diminish from west to east
as the front slowly drifts eastward. A ridge over the eastern
Bering will move inland over Southwest Wednesday morning and will
gradually allow for a clearing trend along the coastal areas of
Southwest through Wednesday afternoon. Weak onshore flow ahead of
the ridge may allow for areas of patchy fog to develop, especially
along the coast overnight tonight and into early Wednesday
morning. By Wednesday evening, another front arrives to Southwest.
This front is noticeably weaker than the previous, however, as it
is well occluded by the time it moves onshore. Additionally, this
front will not advect nearly as much warm air as we saw with the
previous front. Temperatures will be cold enough initially for
snow, and a change to a rain/snow mix is possible along the AKPEN
and Bristol Bay area for Thursday afternoon.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2: Tonight
through Thursday afternoon)...

A storm force low currently centered just south of Shemya will
continue to track westward overnight. The leading edge of the
front will move eastward over the central and eastern Aleutians
for Wednesday. A large area of gales with embedded storm force
winds accompanies this front, however winds will weaken slightly
(down to gales) across most of the Bering through Wednesday
afternoon. Temperatures ahead of the front will be cold enough for
snow, therefore precipitation will initially fall as snow however
as warm air is advected northward, a change to rain is expected.
As the low center moves northwest of Adak Wednesday evening, cold
air will wrap around the backside of the low, generating another
area of storm force winds from the west. While the bulk of these
winds are located well to the south of the western Aleutians, a
few storm force winds will pass over the Rat Islands Wednesday
evening. The low slowly moves eastward Thursday afternoon bringing
rain showers to most of the Bering.

&&

.MARINE (Days 3 through 5)...
A large area of low pressure will move into the Bering Sea over
the weekend, closely following the low anticipated to move in
later this week. An increase in sea ice coverage is possible along
the West Coast late Sunday behind this second low. Meanwhile, a
series of two lows will also move northeast into the Gulf of
Alaska; the first being Friday and the second on Sunday. This
means active weather and small craft to gale force winds for both
areas through the weekend. Confidence is high we will see active
weather and winds. However, confidence is low on the exact
placement of low pressure systems and winds surrounding them as
model guidance is erratic in the long term. This is detailed in
the long term forecast. Overall, gale force winds in the Bering
and Gulf of Alaska can be expected this weekend, with the forecast
needing to be honed further.

&&

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

The long term time frame starts Friday with a low in the eastern
Bering and a low in the Gulf of Alaska. As we continue into the
weekend, the active weather pattern continues as another round of
low pressure enters the Bering. Broad low pressure encompasses the
Bering and Southwest Alaska continues into early next week. A low
is expected to spin off this area of low pressure and move into
the northern Gulf of Alaska, which should bring some weather to
southcentral Alaska.

Models are in general agreement on this pattern, especially that
broad low pressure will be present in the Bering. However, models
are not doing well handling the specific placement of lows entering
the Bering and Gulf of Alaska. There is a considerable difference
between the GFS and other models for the low entering the Bering
this weekend, with the GFS favoring one stronger low and other
models resolving features with two lows. Placement is also an
issue with models for the low entering the Gulf of Alaska early
next week. So, we know there will be an active weather pattern
for all of our forecast area. However, due to large inconsistencies
between guidance on systems, confidence is low as to exactly how
the weather will play out in the long term.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Storms 173-178 411 413 155 165 170-172 179-181 185 412 414.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...TM
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KO/SEB
MARINE/LONG TERM...BB