Gale Warning 688, NWS Anchorage, AK

817 
FZAK62 PAFC 221250
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
350 AM AKST Fri Dec 22 2017

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.

PKZ499-230145-
350 AM AKST Fri Dec 22 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 978 mb low at 56N 167W moves into the Gulf of Anadyr at 985 mb
Sat morning. The associated front wraps over the Eastern Bering
through Sat morning. A 975 mb low at 48N 155W Fri afternoon moves
along the front to 55N 154W at 990 mb for Sun morning. Three 995 
mb lows slip across the Western Bering by Sun morning.

$$

PKZ411-230145-
Bering Sea Offshore West of 180 and East of the International
Dateline-
350 AM AKST Fri Dec 22 2017

...GALE WARNING TODAY...

.TODAY...NW wind 20 to 35 kt. Seas 8 to 16 ft. Freezing spray.
.TONIGHT...W wind 15 to 30 kt. Seas 8 to 13 ft. Freezing spray.
.SAT...SW wind 10 to 25 kt. Seas 7 to 11 ft. Freezing spray.
.SAT NIGHT...SW wind 20 to 35 kt. Seas 7 to 12 ft.
.SUN THROUGH MON...N wind 10 to 25 kt. Seas 6 to 11 ft.
.TUE...SE wind 20 to 35 kt. Seas 8 to 13 ft.

$$

PKZ412-230145-
Bering Sea Offshore 171W to 180 and North of 56N-
350 AM AKST Fri Dec 22 2017

...STORM WARNING THROUGH TONIGHT...

.TODAY...NW wind 35 to 50 kt. Seas 18 to 26 ft. Snow.
.TONIGHT...W wind 20 to 35 kt. Seas 12 to 20 ft. Freezing spray.
.SAT...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.SAT NIGHT...W wind 10 to 25 kt. Seas 6 to 11 ft.
.SUN...W wind 10 to 25 kt. Seas 7 to 12 ft.
.MON...NW wind up to 15 kt. Seas 6 to 9 ft.
.TUE...E wind up to 20 kt. Seas 6 ft.

$$

PKZ413-230145-
Bering Sea Offshore 171W to 180 and South of 56N-
350 AM AKST Fri Dec 22 2017

...GALE WARNING TODAY...

.TODAY...NW wind 30 to 45 kt. Seas 16 to 24 ft.
.TONIGHT...W wind 15 to 30 kt. Seas 11 to 19 ft.
.SAT...W wind 10 to 25 kt. Seas 8 to 13 ft.
.SAT NIGHT...W wind 10 to 25 kt. Seas 7 to 12 ft.
.SUN...W wind 10 to 25 kt. Seas 8 to 13 ft.
.MON...NW wind up to 15 kt. Seas 6 to 9 ft.
.TUE...E wind 10 to 25 kt. Seas 5 to 8 ft.

$$

PKZ414-230145-
Bering Sea Offshore East of 171W-
350 AM AKST Fri Dec 22 2017

...GALE WARNING THROUGH SATURDAY...

.TODAY...S wind 20 to 35 kt. Seas 10 to 17 ft. Rain and snow.
.TONIGHT...NW wind 20 to 35 kt. Seas 9 to 17 ft. Rain and snow.
.SAT...NW wind 25 to 40 kt. Seas 12 to 19 ft. Snow with rain.
.SAT NIGHT...NW wind 25 to 40 kt. Seas 10 to 18 ft.
.SUN...W wind 20 to 35 kt. Seas 9 to 16 ft.
.MON...SW wind up to 20 kt. Seas 6 to 10 ft.
.TUE...NE wind up to 15 kt. Seas 3 to 7 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
518 AM AKST Thu Dec 21 2017

.ANALYSIS AND UPPER LEVELS...
Broad troughing remains over the western Bering Sea while the
active portion of the jet stream is well south of the Aleutians. A
sharp trough sits south of the central/eastern Aleutians at the
leading edge of the east Asian jet protruding into the northern
Pacific. Ahead of this trough, there are two features of interest
with regards to the upcoming forecast, the first a broad upper
level ridge extending across most of the southern mainland, and a
closed off low spinning toward the northern Pacific/western Gulf
of Alaska. The upper low is beginning to phase into the
approaching Bering trough.

Surface high pressure sits over the Gulf of Alaska helping to
create areas of fog and low clouds around the Cook Inlet region.
Surface low pressure centers sit over the central Bering Sea
creating a tight pressure gradient and gusty winds from the
eastern Aleutians through the southwest Mainland.

&&

.MODEL DISCUSSION...
Guidance continues to have a good handle on the synoptics of the
pattern, but struggle a bit with phasing of the Pacific system
into the Bering Sea trough. All guidance phases the system, but
how much and exactly where the resultant surface low sets up are
still in question.

&&

.AVIATION...
PANC...Generally VFR conditions and light winds will persist.
Fog/low stratus will be an issue early this morning around Knik
Arm but should be pushed away by increasing southeast winds off
the surface as the morning progresses.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The upper level ridge is building over Southcentral Alaska
through the Alcan border today. This ridge will persist for a few
days keeping a rather stable pattern over the area. There will be
the threat of fog over inland areas and the Cook Inlet region with
the warm air aloft and otherwise clear skies.

For the western Gulf of Alaska and Kodiak this pattern will bring
in a persistent frontal zone with strong winds and rain. When this
rain and wind moves into the area later today, it will persist
into Saturday night before really tapering off.

Marine areas will see widespread Gale and Storm force winds with
seas building to the 20 to 30 ft range.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...
Clouds and southeasterly winds will continue to increase today
ahead of storm force low currently tracking from the North Pacific
towards the AK pen. This system will take a slightly more
westerly track into the Central Bering than initially projected,
which should help prevent high winds from spreading throughout all
of Bristol Bay. There is however good confidence that this system
will bring high wind gusts to the downslope and gap wind prone
areas along the Aleutian Range, including into the King Salmon and
Iliamna areas by late tonight, so the High Wind Watch was upgraded
to a warning. Further north over the Kuskokwim Delta this low
will also bring strong winds to the coast, along with a brief
round of snow/blowing snow before strong warm air advection
switches most of the area to rain and well above freezing by
Friday afternoon. The one exception to this rule will be for the
lower Kuskokwim Valley which will only see a glancing blow from
the front and allow for temperatures to remain cold enough to
support snow. Most of the snowfall should generally be limited to
the Aniak area and likely as a rain/snow mix, while cooler areas
to the east should only expect showers to pass through and minimal
accumulations.

A broad trough will then bring continued active weather to the
region into Saturday as another gale-storm force North Pacific low
quickly replaces it. The good news from this second system is
that the models have all trended weaker and further west with
it's low position, so there no longer looks to be the potential
for a multi-day high wind event for Bristol Bay as thought
yesterday. There is however good confidence that strong and gusty
winds will continue through Saturday with rains away from
downslope prone areas and well above normal temperatures.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...
The broad trough that has now shifted to the Western Bering will
bring continued active weather from the Central Bering eastward
into this weekend. The first system will bring storm force winds
and rain to the AK pen/Eastern Bering by this afternoon, with
widespread gale force winds expected in the northwesterly flow
behind it. There will also be strong cold air advection along with
the NW flow, which should provide enough cold air to bring
accumulating snow down to sea level from the Dutch Harbor area
westward. Temperatures should remain near-above freezing in most
of these areas, limiting the blowing snow potential. This pattern
will then hold into Saturday as another gale to potentially storm
force North Pacific low takes a very similar northerly track into
the Eastern Bering.

&&

.LONG TERM FORECAST (Friday through Tuesday)...
By Friday, southern Alaska will be in the thick of things
weather-wise, with a low pressure system in the northern Bering
and another one close on its heels south of the AK Pen. This will
bring a strong series of fronts through Southwest Alaska, and
Bristol Bay and the Bering side of the AK Pen can expect some very
windy conditions. Precipitation on the Pacific side of the AK Pen
and Kodiak Island will also be significant, although not as much
as initially shown several days ago. On the western or backside of
these low pressure systems, some strong cold air advection will
move into the Pribilofs and Eastern Aleutians, which will bring
some heavy snow showers and possible blowing snow through Saturday
night.

On Saturday, the ridge holding those lows in place will weaken,
allowing the front over Kodiak to slide eastward and bring
precipitation to the southern Kenai peninsula. A secondary low is
forecast to form just south of the Kenai and move into the Gulf of
Alaska, which should keep down-inlet flow for Southcentral and
keep the weekend cool. Unfortunately, this northerly flow looks to
remain pretty dry, decreasing any chances of snow for the
northern portions of Southcentral. Tuesday looks like it will
clear out over most of the mainland. By Wednesday, the forecast
models are struggling to agree on a solution. Currently, the GFS,
EC and Canadian agree on bringing a strong low up toward the AK
Pen from the north Pacific. However, previous runs have shown
significantly different solutions, so confidence in the day 7
forecast is low. &&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning 161
MARINE...Gale 119 120 136 137 138 139 141 170 171 172 173 174 175 176
              177 178 179 181 185
         Storm 130 131 132 150 155 160 165 180.

&&

SYNOPSIS AND MODEL DISCUSSION...MTL
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DEK
LONG TERM...LF