Gale Warning 741, NWS Anchorage, AK

000 
FZAK61 PAFC 130028
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
328 PM AKST Wed Dec 12 2018

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-131530-
328 PM AKST Wed Dec 12 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A low at 57N 143W will move into the eastern Gulf Thu morning. A
987 mb Bering low will move near 58N 155W at 987 mb Thu night 
then it will move inland over the Kenai Peninsula and dissipate 
Fri morning. A front associated with a North Pacific low will move
into the Gulf Fri afternoon.

$$

PKZ351-131530-
Gulf of Alaska Offshore North of 57N and West of 144W-
328 PM AKST Wed Dec 12 2018

...GALE WARNING THROUGH THURSDAY...

.TONIGHT...NW wind 20 to 35 kt. Seas 12 ft. Rain and snow showers.
.THU...W wind 10 to 25 kt becoming SW 20 to 35 kt in the
afternoon. Seas 11 to 18 ft. Rain showers and snow showers.
.THU NIGHT...SW wind 15 to 30 kt. Seas 13 to 18 ft.
.FRI...S wind 10 to 25 kt. Seas 8 to 13 ft.
.FRI NIGHT...SE wind 25 to 40 kt. Seas 12 to 20 ft.
.SAT THROUGH SUN...SE wind 25 to 40 kt. Seas 13 to 21 ft.
.MON...SE wind 10 to 20 kt. Seas 9 to 13 ft.

$$

PKZ352-131530-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
328 PM AKST Wed Dec 12 2018

...GALE WARNING THROUGH THURSDAY...

.TONIGHT...W wind 25 to 40 kt. Seas 12 to 17 ft.
.THU...SW wind 25 to 40 kt. Seas 15 to 19 ft.
.THU NIGHT...SW wind 15 to 30 kt. Seas 11 to 17 ft.
.FRI...S wind 20 to 35 kt. Seas 9 to 14 ft.
.FRI NIGHT...E wind 30 to 45 kt. Seas 15 to 23 ft.
.SAT THROUGH SUN...W wind 25 to 40 kt. Seas 15 to 23 ft.
.MON...W wind 10 to 20 kt. Seas 10 to 16 ft.

$$

212 
FZAK61 PAFC 131244
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
344 AM AKST Thu Dec 13 2018

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-140200-
344 AM AKST Thu Dec 13 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A trough extends across the North Gulf Coast through Sat morning.
A 955 mb low near 51N 157W moves to 54N 151W at 959 mb Sat 
morning.

$$

PKZ351-140200-
Gulf of Alaska Offshore North of 57N and West of 144W-
344 AM AKST Thu Dec 13 2018

.TODAY...SW wind 15 to 30 kt. Seas 11 to 19 ft. Snow showers.
.TONIGHT...SW wind 20 to 30 kt. Seas 11 to 19 ft. Snow showers.
.FRI...S wind 15 to 30 kt. Seas 9 to 14 ft.
.FRI NIGHT...SE wind 30 to 45 kt. Seas 14 to 22 ft.
.SAT...E wind 35 to 50 kt. Seas 20 to 30 ft.
.SUN...SE wind 10 to 25 kt. Seas 14 to 22 ft.
.MON...SE wind 10 to 20 kt. Seas 9 to 13 ft.

$$

PKZ352-140200-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
344 AM AKST Thu Dec 13 2018

...GALE WARNING THROUGH FRIDAY...

.TODAY...SW wind 25 to 40 kt. Seas 16 to 20 ft.
.TONIGHT...SW wind 25 to 35 kt diminishing to 15 to 30 kt after
midnight. Seas 11 to 18 ft.
.FRI...S wind 15 to 25 kt becoming SE 25 to 40 kt in the
afternoon. Seas 9 to 15 ft.
.FRI NIGHT...E wind 40 to 55 kt. Seas 15 to 29 ft.
.SAT...E wind 35 to 50 kt. Seas 20 to 30 ft.
.SUN...W wind 15 to 30 kt. Seas 15 to 22 ft.
.MON...W wind 10 to 20 kt. Seas 10 to 16 ft.

$$

566 
FZAK61 PAFC 132357
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
257 PM AKST Thu Dec 13 2018

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-141515-
257 PM AKST Thu Dec 13 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

Low pressure persists in the Gulf through Fri morning. A front
enters the southern Gulf Fri afternoon then it intensifies and
moves into the northern Gulf Sat.

$$

PKZ351-141515-
Gulf of Alaska Offshore North of 57N and West of 144W-
257 PM AKST Thu Dec 13 2018

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 20 to 30 kt. Seas 12 to 19 ft. Isolated Thunderstorms.
.FRI...S wind 15 to 30 kt. Seas 9 to 14 ft.
.FRI NIGHT...E wind 35 to 45 kt. Seas 14 to 22 ft.
.SAT...E wind 35 to 50 kt. Seas 20 to 29 ft.
.SAT NIGHT...E wind 35 to 50 kt. Seas 20 to 29 ft.
.SUN...SE wind 10 to 25 kt. Seas 14 to 22 ft.
.MON THROUGH TUE...NW wind 10 to 25 kt. Seas 9 to 16 ft.

$$

PKZ352-141515-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
257 PM AKST Thu Dec 13 2018

...STORM WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 25 to 40 kt diminishing to 15 to 30 kt after 
midnight. Seas 14 to 23 ft. Isolated Thunderstorms.
.FRI...S wind 15 to 30 kt becoming SE 25 to 40 kt in the
afternoon. Seas 10 to 17 ft. Rain.
.FRI NIGHT...E wind 35 to 45 kt increasing to 40 to 55 kt after
midnight. Seas 16 to 24 ft building to 22 to 29 ft after midnight.
Rain.
.SAT...E wind 35 to 50 kt. Seas 23 to 29 ft.
.SAT NIGHT...NE wind 15 to 30 kt. Seas 20 to 28 ft.
.SUN...W wind 10 to 25 kt. Seas 15 to 22 ft.
.MON THROUGH TUE...NW wind 15 to 30 kt. Seas 11 to 19 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion...CORRECTED
National Weather Service Anchorage AK
536 PM AKST Tue Dec 11 2018

.ANALYSIS AND UPPER LEVELS...
A persistent, negatively tilted long wave trough encompasses the
Bering and is pushing into the Gulf. Northerly flow persists over
much of southwest Alaska and the Bering as cold, Arctic air is
being advected behind the trough. A weak low has formed over the
western Aleutians. Weather in the west is fairly benign with only
light precipitation falling over the western mainland and weak
winds through the Bering. Within the flow around the trough, a
shortwave extends over the eastern Aleutians with a North Pacific
low anchored at the base. This low is well south of the Aleutian
chain and is tracking eastward. A second short wave is spread over
the northern Gulf which is driving much of the weather for the
area. A strong band of increased vorticity is extending from
Kodiak Island through the Gulf, coinciding with the shortwave.
Throughout Southcentral, winter weather has returned. At the
surface, a closed low pressure system sits over eastern Prince
William Sound which is causing strong advection of cold air over
Southcentral and the western Gulf. Winds are increasing and
southwesterly flow is dominant through the Cook Inlet and western
Gulf. A surface shortwave over the northern Gulf coast is aiding
precipitation formation in Southcentral mainly in the form of snow
showers.

&&

.MODEL DISCUSSION...
The numerical models are not in very good agreement and are
showing poor run-to-run consistency. However, when it comes to
the sensible weather, they come to a similar conclusion on many of
the important features. The low pressure in Prince William Sound
has decent agreement as it remains nearly stationary through
Wednesday morning. As the North Pacific low traverses eastward,
models quickly diverge. As it reaches the southern Gulf on
Wednesday morning, the ECMWF is a far faster solution while the
GFS and NAM lag behind. The GFS is the strongest of the solutions
when it comes to wind speeds while the NAM is weaker. A blend was
used to find a middle ground. Models return to a similar track on
Thursday as this low moves into the eastern Gulf.

In the west, models again are out of sync. Starting early
Wednesday morning, the once closed low over the western Aleutians
breaks down and becomes generalized low pressure over the area.
Models, while they agree on this pattern, do not have a consensus
on the organization of the multiple lows. On Thursday, as a low
originating in Norton Sound moves into the eastern Bering, models
are in good agreement.

&&

.AVIATION...

PANC...MVFR to IFR conditions in snow are expected through the TAF
period. A few VFR breaks are possible, but these will only last a
few hours at most. Brief gusty south winds are possible this
evening, but in general winds will be light.

&&

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

The pattern will remain favorable for continued light snow. Snow
across Southcentral today will likely continue throughout this
evening until Thursday morning and evening as the surface low
remains in place. The intensity may ebb and flow, but it should
remain more or less continuous. As a result, POPs were increased
from the morning forecast package from the Kenai Peninsula through
Prince William Sound, to include the Anchorage Bowl. While light
snow will be persistent, low QPF will limit accumulations.
Generally a few inches are expected over the next 36 hours.

Below freezing temperatures stretch across the region and will
continue to sit below freezing through the remainder of the week,
as a low over the northern Bering pushes cold air advection across
Southcentral. Most places will see relatively calm winds. However,
places along the western Kenai Peninsula will continue to see
gusty conditions. The wind combined with the cold will make for
seasonable wind chills. Some blowing snow along the Homer Bluff is
possible through the evening hours, however, visibilities should
remain above advisory criteria.

Uncertainty remains in today's forecast with the low south of the
Chain that will move into the eastern Gulf for Wednesday
afternoon. Models continue to struggle with the placement and
intensity of this low, which in turn will impact the wind speed
and direction across the Gulf into the north Gulf coast. Thus,
little changes were made to this part of the forecast today.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Tuesday
night through Friday)...
Low pressure to the north, centered in Norton Sound will be the
weather influencer for the remainder of the work week. It is
expected to continue to wrap cold air into southwest AK behind it,
bringing the coldest temperatures so far this winter to the area.

The big question here will be onshore flow also induced by wind
direction. So, cloud cover will likely prevent temperatures from
falling too much, especially along the coast. However, how far
inland the cloud cover will push will be the main factor in the
forecast. Right now, thinking cloud cover will push inland except
for eastern areas of zones 161 and 152, so have the coldest temps
forecast in those areas. If cloud cover does clear and winds
drop, temperatures will drop quick, so this bears watching the
next couple of days.

The low will then push south into Bristol Bay Thursday, changing
the wind direction and creating offshore flow. This will almost
certainly clear out the cloud cover for southwest AK. Meanwhile,
high pressure will build over the interior, so high confidence
that cold temps from north of the Alaska Range will be working
their way into southwest AK later this week.

&&

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

Northwest flow is the name of the game for the next few days. This
means cooling temperatures and cold weather cumulus with snow
showers will persist over much of the area. While the broad
scale conditions are predictable, timing out snow showers at
airfields throughout the Bering has made some interesting
aviation forecasting. Snow showers have been intense and fast
moving, quickly reducing visibility in snow. Winds are also gusty
with these showers as they are able to mix down winds aloft. This
type of weather can be expected to continue.

This pattern is resultant from a low pressure system generally
located in Norton Sound, wrapping cold air all the way from the
arctic behind it. In fact, this airmass originated in the high
arctic. Cold air is being funneled southwest around a high
pressure system in the Arctic Ocean and along the north Slope.
This air then enters the influence of the low and pushes south
through the Chukchi Sea, through the Bering Strait and all the way
into the Bering Sea. Quite the journey and this shows how
interconnected our weather is through the whole of the upper
latitudes. This low pressure will meander south along the coast
the next couple of days, but will maintain its influence through
Friday.

Outside of this cold air push, the Aleutians will see a couple of
compact lows push west to east across the chain tomorrow. This
will bring some spotty precipitation and gusty winds to the chain.

&&

.LONG TERM FORECAST (Days 4 through 7)...

The forecast period commences with the longwave trough extending
from Western Alaska to the Gulf Of Alaska, meanwhile the ridge
will be over the Central Aleutians. On the 15th of December at 12z
the GFS at 500 mb, has a closed low near the Brooks Range,
another in the Gulf Of Alaska and a third one southwest of Attu
Island. The ECMWF is pretty similar although the feature south of
the Western most Aleutians is depicted as more of an open wave.
Each upper level disturbance has multiple shortwaves embedded
with the cyclonic flow. At the surface, the GFS and ECMWF have
rendered some pretty significant differences with the placement of
the surface lows early in the forecast period. Generally
speaking, expecting a progressive pattern this forecast period.
However, given the vagaries of the models hedged towards NCEP WPC
guidance for the pops.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gales...119 120 130 131 132 138 139 141 150 155 165 170
				 177 178 179.
		 Heavy Freezing Spray...185.

&&

SYNOPSIS AND MODEL DISCUSSION...RA/BL
SOUTHCENTRAL ALASKA...AH/MO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BB
LONG TERM...PJS