Storm Warning 82, NWS Anchorage, AK

929 
FZAK62 PAFC 241150
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
350 AM AKDT Sun Mar 24 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.

PKZ499-250130-
350 AM AKDT Sun Mar 24 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A front over the central Bering moves inland by Sun afternoon. A
front moves over the central Aleutians by Sun afternoon. The
associated 964 mb low at 48N 176E Sun afternoon moves to 53N 179E
at 954 mb by Mon morning and then moves into the northern Bering
by Tue morning.

$$

PKZ411-250130-
Bering Sea Offshore West of 180 and East of the International
Dateline-
350 AM AKDT Sun Mar 24 2019

...GALE WARNING THROUGH MONDAY...

.TODAY...SW wind 25 to 40 kt becoming S 15 to 30 kt in the
afternoon. Seas 15 to 23 ft.
.TONIGHT...NE wind 20 to 35 kt. Seas 10 to 17 ft. Rain and snow.
.MON...W wind 30 to 45 kt. Seas 12 to 20 ft. Rain showers and
snow.
.MON NIGHT...SW wind 30 to 45 kt. Seas 16 to 24 ft.
.TUE THROUGH THU...S wind 15 to 30 kt. Seas 12 to 20 ft.

$$

PKZ412-250130-
Bering Sea Offshore 171W to 180 and North of 56N-
350 AM AKDT Sun Mar 24 2019

...STORM WARNING MONDAY...

.TODAY...S wind 20 to 30 kt. Seas 12 to 19 ft.
.TONIGHT...SE wind 30 to 45 kt. Seas 13 to 20 ft. Rain and snow.
.MON...S wind 40 to 55 kt. Seas 17 to 32 ft.
.MON NIGHT...S wind 35 to 50 kt. Seas 20 to 31 ft.
.TUE THROUGH THU...S wind 15 to 30 kt. Seas 12 to 20 ft.

$$

PKZ413-250130-
Bering Sea Offshore 171W to 180 and South of 56N-
350 AM AKDT Sun Mar 24 2019

...STORM WARNING TONIGHT AND MONDAY...

.TODAY...SW wind 15 to 30 kt becoming SE in the afternoon. Seas
10 to 18 ft. Rain.
.TONIGHT...SE wind 30 to 40 kt becoming S 35 to 50 kt after
midnight. Seas 13 to 21 ft. Rain.
.MON...S wind 40 to 55 kt becoming SW 35 to 45 kt in the
afternoon.
Seas 18 to 29 ft. Rain showers.
.MON NIGHT...SW wind 25 to 40 kt. Seas 17 to 26 ft.
.TUE THROUGH THU...S wind 15 to 30 kt. Seas 10 to 18 ft.

$$

PKZ414-250130-
Bering Sea Offshore East of 171W-
350 AM AKDT Sun Mar 24 2019

...GALE WARNING TONIGHT AND MONDAY...

.TODAY...S wind 10 to 25 kt. Seas 7 to 10 ft.
.TONIGHT...SE wind 20 to 35 kt increasing to 30 to 45 kt after
midnight. Seas 9 to 17 ft.
.MON...S wind 30 to 45 kt. Seas 14 to 21 ft. Rain.
.MON NIGHT...S wind 20 to 35 kt. Seas 13 to 21 ft.
.TUE THROUGH THU...S wind 10 to 25 kt. Seas 7 to 12 ft.

$$

643 
FZAK62 PAFC 250004
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
404 PM AKDT Sun Mar 24 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.

PKZ499-251245-
404 PM AKDT Sun Mar 24 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A 960 mb low at 48N 175E moves to 57N 178E at 948 mb Mon morning
then shifts to Northern Kamchatka and inland at 958 mb for Tue 
morning. Its front sweeps the Aleutians and Bering through Tue
afternoon.

$$

PKZ411-251245-
Bering Sea Offshore West of 180 and East of the International
Dateline-
404 PM AKDT Sun Mar 24 2019

...STORM WARNING MONDAY...

.TONIGHT...NE wind 30 to 45 kt. Seas 11 to 16 ft. Rain and snow.
.MON...W wind 35 to 50 kt. Seas 14 to 22 ft. Rain and snow.
.MON NIGHT...SW wind 30 to 45 kt. Seas 15 to 25 ft.
.TUE...SW wind 15 to 30 kt. Seas 13 to 19 ft.
.TUE NIGHT...SW wind 20 kt. Seas 11 to 14 ft.
.WED...S wind 15 to 25 kt. Seas 9 to 17 ft.
.THU THROUGH FRI...SE wind 20 to 30 kt. Seas 15 to 23 ft.

$$

PKZ412-251245-
Bering Sea Offshore 171W to 180 and North of 56N-
404 PM AKDT Sun Mar 24 2019

...STORM WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...SE wind 30 to 45 kt. Seas 13 to 19 ft. Rain and snow.
.MON...S wind 45 to 60 kt. Seas 17 to 28 ft building to 23 to 34
ft in the afternoon. Widespread rain showers.
.MON NIGHT...S wind 35 to 50 kt diminishing to 25 to 40 kt after
midnight. Seas 21 to 33 ft.
.TUE...S wind 30 kt. Seas 17 to 23 ft.
.TUE NIGHT...S wind 20 to 30 kt. Seas 13 to 18 ft.
.WED THROUGH FRI...SE wind 10 to 25 kt. Seas 10 to 18 ft.

$$

PKZ413-251245-
Bering Sea Offshore 171W to 180 and South of 56N-
404 PM AKDT Sun Mar 24 2019

...HURRICANE FORCE WIND WARNING MONDAY...

.TONIGHT...SE wind 35 to 45 kt becoming S 45 to 60 kt after
midnight. Seas 14 to 22 ft. Rain.
.MON...S wind 50 to 65 kt becoming SW 40 to 50 kt in the
afternoon. Seas 20 to 31 ft. Widespread rain and snow showers.
.MON NIGHT...SW wind 25 to 40 kt becoming 30 kt after midnight.
Seas 18 to 27 ft.
.TUE...S wind 20 to 30 kt. Seas 15 to 20 ft.
.TUE NIGHT...S wind 15 to 30 kt. Seas 11 to 17 ft.
.WED THROUGH FRI...SE wind 10 to 25 kt. Seas 9 to 17 ft.

$$

PKZ414-251245-
Bering Sea Offshore East of 171W-
404 PM AKDT Sun Mar 24 2019

...GALE WARNING THROUGH MONDAY NIGHT...

.TONIGHT...SE wind 25 to 40 kt. Seas 9 to 17 ft. Rain.
.MON...S wind 25 to 40 kt. Seas 15 to 23 ft. Rain.
.MON NIGHT...S wind 20 to 35 kt. Seas 14 to 22 ft.
.TUE...S wind 15 to 25 kt. Seas 11 to 17 ft.
.TUE NIGHT...S wind 10 to 25 kt. Seas 9 to 16 ft.
.WED THROUGH FRI...SE wind 10 to 25 kt. Seas 6 to 11 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
420 AM AKDT Sat Mar 23 2019

.ANALYSIS AND UPPER LEVELS...
An active pattern remains over the western Aleutians and Bering as
a front associated with a mature low moves eastward towards
Shemya, which has seen strong winds and snow overnight.
The latest ASCAT/advanced scatterometer pass has detected gale
force winds near Attu and Shemya with this new storm. A weakening
low over Bristol Bay that is bringing a few rain showers to areas
across the Southwest Alaskan coast as temperatures remain above
freezing. The front over the Gulf Of Alaska remains to be the main
weather driver for Southcentral this morning. The radar at Kenai
(PAHG) and Middleton Island (PAIH) have been active overnight and
early this morning. Areas along the north Gulf coast continue to
be influenced by the warm influx of moisture lifting northward
from the Gulf resulting in rain showers stretching from Homer to
Cordova. The warm trend continues, yesterday the highs at
Birchwood, Wasilla, Talkeetna and Kenai were 51F.

&&

.MODEL DISCUSSION...
The global models are in good agreement with the synoptic scale
features through 00z Monday. Moreover, the GFS ensemble members
are tightly grouped with the high over the Arctic Ocean, the low
near the AKPEN and the low south of Kamchatka. There are some
minor differences with the areal coverage of the precipitation
shield over Southwest AK and over portions of Southcentral AK.
The NAM was used to for high resolution winds for portions of
Southcentral, but otherwise, the model of choice for the short
term package was the GFS.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist in the morning.
The cigs/ceilings will vary between 5,000 to 7,000 today at PANC.
By 6z, gusty winds will move out of Turnagain Arm and into the
PANC aerodrome.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A frontal system will remain across the area today, stretching
from the Alaska Range west of Skwentna east-southeast across the
Kenai Peninsula through the north Gulf coast. This is bringing
precipitation to the area, mainly along the eastern Kenai and
towards the western Alaska Range. The air mass is quite warm and
the precipitation at low elevation sites is in the form of rain. A
surface low developing to the southwest of Yakutat will slide
west-northwest today along the front, crossing the Kenai Peninsula
this afternoon and then moving across the Susitna Valley. This
will bring some gusty winds into the Knik Valley this afternoon
and into Anchorage in the evening. The front will then push
northward across Southcentral tonight. Another front associated
with a low south of the Gulf will move to the north Gulf coast
Sunday morning. As this front moves inland Sunday afternoon, the
flow aloft will switch from southeasterly to southwesterly. On
Sunday night a ridge of high pressure will begin to build into the
area, with conditions drying out.

&&

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

A 990 mb surface low just to the west of Kuskokwim Bay will
continue to track north while weakening, leading to subsiding
southeasterly winds and diminishing areas of precipitation today.
The next system approaches the area by early Sunday morning as a
front pushes across the SW coast. Most of the energy looks to
remain north over the Kuskokwim Delta, with strong southeasterly
winds and snowfall developing Sunday morning. The pattern begins
to change by Sunday night as a high amplitude longwave ridge
builds north over the mainland bringing another surge of warm
temperatures with persistent southerly flow at the surface.
Temperatures look to climb well into the 40s with some locations
reaching into the low 50s during the day on Monday. A strong low
approaches from the west by Monday with southeasterly winds
ramping up again along the coast. There were some concerns
regarding possible storm surge issues along the coast but the
track of the low is trending further west, keeping the wind
direction unfavorable for building surge high enough to be
impactful to coastal communities.

&&

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

Northerly winds will continue to diminish today over the eastern
Bering as a surface low to the east weakens. Fairly benign weather
will be present over the eastern Bering/Aleutians as a short wave
ridge moves over the area out ahead of the next system pushing
east across the Bering. Out west, a front pushing out ahead of a
surface low near Kamchatka will bring easterly gale force winds switching
to southwesterly as the front passes today. Gales look to
continue over the western Bering through early Sunday morning
before briefly diminishing later in the morning.

Attention turns to a very strong low rapidly approaching the west
Aleutians from the North Pacific by Sunday afternoon. The low
looks to rapidly intensify as it approaches, with the EC deepening
the central pressure from 970 mb to 946 mb between Sunday and
Monday morning (24 mb in 24 hrs). Models are mostly locked on to
the low, with the center tracking north across the Rat Islands and
into the western Bering Sunday night. Ahead of the low, a warm
front will push into the Bering Sunday evening bringing gale force
southerly winds and heavy rain. The strongest winds are expected
with the proceeding cold frontal passage across the western
Aleutians, with strong cold air advection (850 mb temps dropping
from +6c to -8C Sunday night) wrapping in around the backside of
the low. This will likely lead to hurricane force wind gusts near
Adak Sunday night into Monday morning before the narrow core of
strong winds pushes north into the western Bering through Monday
afternoon.

&&

.MARINE (Days 3 through 5)...

Gulf of Alaska... Expect generally benign conditions, with winds
diminishing and seas subsiding as pressure builds.

Bering Sea... Confidence is high that a storm force low will
track into the Bering Sea from the western Aleutians Monday.
This will bring heavy seas and widespread gales to the central
Bering and Aleutians, with a swath of storm force winds southeast
of the low. The low will weaken and shift northward towards
eastern Siberia by Tuesday and winds will diminish.

&&

.LONG TERM FORECAST (Days 3 through 7)...
Confidence remains strong that a pattern change to drier
weather will begin over Southcentral Monday, as a longwave ridge
begins building over the area. Daytime conditions will trend at
least as warm as observed this week in most areas, though valley
locations will likely see colder nights driven by clear skies.
With ample surface moisture and atmospheric stability, there will
also be potential for morning fog which could decrease the
diurnal temperature range. The main question is when the ridge
will degrade, and model agreement is poor on that decision. Some
solutions show the ridge breaking down as early as midweek, with a
return to wetter weather following. That said, there is
indication that a high will rebuild and return the warm, dry
conditions into next weekend.

Looking farther west, a potent low will track from the western
Aleutians to the central Bering Monday. With an expected moisture
fetch almost to the tropics, expect heavy precipitation ahead of
the low. As the low shifts northward, the front and associated
precipitation and winds will progress eastward over the Aleutians
and Bering, then stall over Southwest Tuesday. A ridge in place
over Southcentral will likely diminish precipitation potential
over the Southwest mainland. Showers in cold air advection will
persist behind the front in the Bering Tuesday into Wednesday.
Forecast confidence drops substantially Wednesday
onward...based on model consistency, this forecast package is
leaning more towards quiet weather by midweek. Conditions over
the mainland will depend on the progression of the upper ridge.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 413 411 177 178 181.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...PAMBER
SOUTHCENTRAL ALASKA...BL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KVP
MARINE/LONG TERM...MM