Gale Warning 748, NWS Anchorage, AK

725 
FZAK61 PAFC 211222
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
322 AM AKST Fri Dec 21 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.

PKZ399-220200-
322 AM AKST Fri Dec 21 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 985 mb low at 55N 150W moves to 56N 153W Sat night at 993 mb and
then moves to 59N 146W at 1002 mb Sun night. A front enters the
western Gulf Sun night.

$$

PKZ351-220200-
Gulf of Alaska Offshore North of 57N and West of 144W-
322 AM AKST Fri Dec 21 2018

...GALE WARNING THROUGH TONIGHT...

.TODAY...E wind 20 to 35 kt. Seas 11 to 19 ft.
.TONIGHT...E wind 20 to 35 kt. Seas 13 to 18 ft.
.SAT...E wind 25 kt. Seas 13 to 16 ft.
.SAT NIGHT...SE wind 10 to 20 kt. Seas 10 ft.
.SUN THROUGH MON...W wind up to 20 kt. Seas 6 to 11 ft.
.TUE...SE wind 20 kt. Seas 5 to 8 ft.

$$

PKZ352-220200-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
322 AM AKST Fri Dec 21 2018

...GALE WARNING TODAY...

.TODAY...E wind 20 to 35 kt. Seas 15 to 20 ft.
.TONIGHT...E wind 10 to 25 kt. Seas 11 to 17 ft.
.SAT...S wind 10 to 20 kt. Seas 8 to 13 ft.
.SAT NIGHT...S wind up to 15 kt. Seas 7 to 11 ft.
.SUN THROUGH MON...SW wind up to 20 kt. Seas 7 to 11 ft.
.TUE...SE wind 15 to 30 kt. Seas 7 to 12 ft.

$$

200 
FZAK61 PAFC 220012
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
312 PM AKST Fri Dec 21 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.

PKZ399-221430-
312 PM AKST Fri Dec 21 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 983 mb low at 54N 150W will move to 56N 152W at 988 mb Sat 
afternoon. The low will then move to 57N 150W at 990 mb Sun 
afternoon.

$$

PKZ351-221430-
Gulf of Alaska Offshore North of 57N and West of 144W-
312 PM AKST Fri Dec 21 2018

...GALE WARNING TONIGHT...

.TONIGHT...E wind 20 to 35 kt. Seas 13 to 19 ft. Rain.
.SAT...SE wind 15 to 25 kt. Seas 11 to 16 ft.
.SAT NIGHT...SE wind 20 kt. Seas 10 ft.
.SUN...S wind up to 10 kt. Seas 6 to 9 ft.
.SUN NIGHT...W wind up to 15 kt. Seas 6 to 10 ft.
.MON THROUGH TUE...SE wind 10 to 20 kt. Seas 5 to 9 ft.
.WED...S wind 20 kt. Seas 11 to 16 ft.

$$

PKZ352-221430-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
312 PM AKST Fri Dec 21 2018

.TONIGHT...E wind 10 to 25 kt. Seas 11 to 17 ft.
.SAT...S wind 10 to 20 kt. Seas 9 to 14 ft.
.SAT NIGHT...S wind 15 kt. Seas 6 to 11 ft.
.SUN...SW wind 10 kt. Seas 5 to 8 ft.
.SUN NIGHT...W wind up to 20 kt. Seas 7 to 10 ft.
.MON THROUGH TUE...SE wind 15 to 30 kt. Seas 7 to 12 ft.
.WED...S wind 20 kt. Seas 13 to 17 ft.

$$

101 
FZAK61 PAFC 221235
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
335 AM AKST Sat Dec 22 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.

PKZ399-230145-
335 AM AKST Sat Dec 22 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 984 mb low at 55N 151W moves to 55N 152W at 994 mb Sat night.
The low then weakens and moves to 59N 147W at 1004 mb Sun night. 
A front enters the western Gulf Sun night.

$$

PKZ351-230145-
Gulf of Alaska Offshore North of 57N and West of 144W-
335 AM AKST Sat Dec 22 2018

.TODAY...SE wind 15 to 25 kt. Seas 13 to 17 ft. Isolated
thunderstorms.
.TONIGHT...SE wind 10 to 20 kt. Seas 10 ft.
.SUN...Variable wind 10 kt. Seas 8 ft.
.SUN NIGHT...W wind up to 15 kt. Seas 8 ft.
.MON...SW wind 10 to 20 kt. Seas 6 to 9 ft.
.TUE...SE wind 20 kt. Seas 5 to 8 ft.
.WED...S wind 20 kt. Seas 11 to 16 ft.

$$

PKZ352-230145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
335 AM AKST Sat Dec 22 2018

.TODAY...SE wind 10 to 20 kt. Seas 9 to 14 ft. Isolated
thunderstorms.
.TONIGHT...S wind 15 kt. Seas 8 to 11 ft.
.SUN...W wind up to 15 kt. Seas 7 to 10 ft.
.SUN NIGHT...W wind up to 20 kt. Seas 7 to 11 ft.
.MON...SW wind 15 to 30 kt. Seas 6 to 11 ft.
.TUE...SE wind 15 to 30 kt. Seas 7 to 12 ft.
.WED...S wind 20 kt. Seas 13 to 17 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
501 AM AKST Thu Dec 20 2018

.ANALYSIS AND UPPER LEVELS...

A decaying upper level low is currently centered over the central
Kenai Peninsula this morning. Despite its weakening, its slow
northward movement has created ample lift ahead of it to generate
a snow band that is producing very heavy snow across western
Prince William Sound north of Moose Pass. A Winter Storm Warning
is in effect along the Seward Highway north of Moose Pass. Another
feature of note is a small mesoscale low being captured by the
Kenai radar across southern Cook Inlet, swirling off the coast of
Ninilchik. Notable instability in the low levels is present per
the 12Z Anchorage Sounding. Also, the atmosphere is nearly
saturated throughout the atmospheric column. The combination of
instability and plentiful moisture is allowing most any
meteorological feature, assuming it's producing at least some lift
to use the moisture to cause areas of snow.

Much quieter weather continues across Southwest Alaska with most
areas under clear skies and light winds. This has allowed almost
every single site to drop below zero, with isolated exceptions
where some clouds have developed along the coast allowing those
stations to stay just above zero. Sleetmute is the cold spot so
far this morning with temperatures below minus 20. A large area of
low pressure tracking well south of Cold Bay is providing the
eye-candy in Southern Alaska today with a very well defined hook
and center of circulation. Fortunately the worst conditions should
stay south of the Aleutians and Alaska Peninsula.

&&

.MODEL DISCUSSION...

Model agreement remains dismal this morning, both with respect to
each other, and compared with previous runs. They agree into
Friday on the track of the large area of low pressure over the
North Pacific tracking south of the Eastern Aleutians. Otherwise,
the slow-moving, small size, and ability of these mesoscale areas
of low pressure to form, move over an area perhaps causing briefly
hazardous conditions, then dissipate makes the forecast very
difficult at times. As such, forecast confidence continues to be
low.

&&

.AVIATION...
PANC...A band of light snow that has remained relatively
stationary overnight is very slowly drifting south away from the
airport. While conditions are expected to slowly improve this
morning, the timing of when that will happen given how slow the
band is moving is very uncertain. Once the band finally does
clear, VFR conditions and light winds are forecast until Friday
morning, when the next system approaches and brings another chance
of snow.

&&

.CLIMATE...
This morning, Anchorage International Airport set a new record
for longest streak of consecutive days with measurable snowfall
at 10 days. Here are the top 5 longest streaks of consecutive days
with measurable snowfall in chronological order and how much snow
fell during each one:

1) 10 days- December 11-20, 2018: Total Snowfall: 22.1 inches
2) 9 days- December 4-12, 1991: Total Snowfall: 13.0 inches
3) 9 days- November 26- December 4, 1987: Total Snowfall: 19.3 inches
4) 9 days- February 16-24, 1968: Total Snowfall: 23.4 inches
5) 9 days- March 31- April 8, 1956: Total Snowfall: 10.6 inches

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The east-to-west oriented upper level trough over the area this
morning will slide north today, exiting north of the Alaska Range
this evening. Precipitation will diminish or end as upper level
westerly flow moves into Southcentral. The flow will still be
slightly cyclonic, so chances of snow will remain for areas around
Prince William Sound into the eastern Copper River basin. An upper
level low south of the Alaska Peninsula will move east into the
southern Gulf tonight and Friday, then drift northward Friday
night. A front associated with this low will bring precipitation
into Kodiak Island beginning this afternoon. This precipitation
will continue through Friday night with low level northeasterly
flow. The precipitation will start as snow, and then gradually
turn to rain Friday morning as warm air surges into the area. The
front will reach the north Gulf coast late Thursday night into
Friday morning. Chances of snow will move inland during the day
Friday, and continue Friday night.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Thursday
through Saturday)...

Cold, dry air continues for southwest Alaska. In taking another
look at conditions tonight, thinking cold air at the surface will
remain in place at least for the next day or two before it starts
to moderate. Models have been trying to warm the region for the
past few days, however with temperatures still well into the -20s
in some locations, clearly it is not warming. Historically models
have a tendency to try and warm temperatures back to normal too
early, so accounted for this in the forecast and kept it cold.

The reasoning here is that there is nothing to really push the
cold air out of low lying locations and weak northeast flow will
continue from Interior AK. This points to cold air remaining in
place until we see a solid shift in the wind pattern. Low level
cloud cover that has been wandering in a disorganized fashion will
moderate temps when it moves over specific locations. Forecasting
the movement of this low level stratus is nearly impossible
though, so went with minimum temperatures under scattered or clear
skies. Lastly, fog has begun to develop around Bethel, so will
need to watch this today.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through
3/Thursday through Saturday)...

A mature, occluded low pressure system continues to track east
with its center to the south of the Aleutians. Its occluded
boundary and broad deformation zone are sending snow across the
eastern Aleutians and north to the Pribilofs. Additionally, a weak
surface low that has developed west of the Pribilofs is creating
gusty winds across the south central Bering. This prompted the
issuance of a winter weather advisory for blowing snow in the
Pribilofs. Visibility did reduce yesterday and overnight, but
conditions are improving so we are allowing the advisory to
expire. This surface low will track west today, which will allow
winds to gradually slacken through the day. Friday morning the
next low will enter the western Aleutians, bringing the next round
of weather.

&&

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

Saturday starts off by bringing a weakening low into the southern
Gulf with gusty conditions along the north Gulf coast. The exact
position of the low is still a bit different between models, but
no matter where it is, offshore flow and precipitation along
coastal areas of Southcentral should will be the main focus for
the weekend. Early next week (Mon/Tues) should remain relatively
dry for Southcentral.

Models have come into better agreement with a surface low moving
over the western Aleutians on Saturday, which previous models
showed as a front. The models tend to show this low weakening by
Sunday as another deep low sitting south of Adak lifts northward
over the Aleutian Chain. A front associated with this low will
move into the Gulf sometime between Tuesday and Thursday. Exact
movement and intensity of this low remains to be the biggest
forecast challenge as it looks to weaken and move into the Bering
through the middle of next week. Updating these low features were
the focus of today's forecast.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning: 125.
MARINE...Gale Warning: 155 172 174-178 185 411 412.
Heavy Freezing Spray Warning: 160 180-185.

&&

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

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
940 AM AKST Thu Dec 20 2018

AKZ101-210000-
Anchorage-
Including the cities of Anchorage, Eagle River, Indian,
and Eklutna
940 AM AKST Thu Dec 20 2018

...FREEZING DRIZZLE ACROSS THE ANCHORAGE BOWL...

Areas of freezing drizzle are expected to continue across the
Anchorage Bowl into the early afternoon hours today. This will
make for slick conditions in areas with bare pavement. Drivers
should allow extra time when traveling.