Gale Warning 19, NWS Anchorage, AK

375 
FZAK61 PAFC 250040
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
340 PM AKST Wed Jan 24 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.

PKZ399-251445-
340 PM AKST Wed Jan 24 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A weak trough remains nearly stationary over the North Gulf Coast
and Eastern Gulf through Fri afternoon. A 1000 mb low forms at 
54N 150W Fri morning and remains nearly stationary for Fri 
afternoon.

$$

PKZ351-251445-
Gulf of Alaska Offshore North of 57N and West of 144W-
340 PM AKST Wed Jan 24 2018

.TONIGHT...NW wind 15 to 30 kt. Seas 6 to 11 ft. Freezing spray.
.THU...NW wind 15 to 30 kt. Seas 7 to 11 ft. Freezing spray.
.THU NIGHT...W wind 10 to 25 kt diminishing to up to 15 kt after
midnight. Seas 6 to 11 ft. Freezing spray.
.FRI...SW wind 10 to 25 kt. Seas 5 to 10 ft.
.FRI NIGHT...E wind up to 15 kt. Seas 3 to 6 ft.
.SAT...E wind 10 to 20 kt. Seas 5 ft.
.SUN THROUGH MON...NW wind 10 to 25 kt. Seas 6 to 11 ft.

$$

PKZ352-251445-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
340 PM AKST Wed Jan 24 2018

...GALE WARNING THURSDAY...

.TONIGHT...NW wind 15 to 30 kt. Seas 10 to 14 ft. Freezing spray.
.THU...NW wind 30 kt becoming 20 to 35 kt in the afternoon. Seas
11 to 15 ft. Freezing spray.
.THU NIGHT...NW wind 15 to 30 kt becoming W up to 20 kt after
midnight. Seas 9 to 14 ft. Freezing spray.
.FRI...S wind 10 to 25 kt. Seas 5 to 10 ft.
.FRI NIGHT...E wind 10 to 20 kt. Seas 4 to 8 ft.
.SAT THROUGH MON...NW wind 10 to 25 kt. Seas 6 to 11 ft.

$$

868 
FZAK61 PAFC 251223
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
323 AM AKST Thu Jan 25 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.

PKZ399-260215-
323 AM AKST Thu Jan 25 2018
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 992 mb low at 57N 142W moves over Middleton Island tonight at
995 mb and then dissipates. A second 990 mb low at 52N 137W moves
over Middleton Island Fri afternoon at 1004 mb and then moves
inland Fri night. A complex 1000 mb low forms near 54N 152W Fri
morning and exits the Gulf to the south Fri night.

$$

PKZ351-260215-
Gulf of Alaska Offshore North of 57N and West of 144W-
323 AM AKST Thu Jan 25 2018

.TODAY...NW wind 15 to 30 kt. Seas 7 to 12 ft. Freezing spray.
.TONIGHT...W wind 10 to 25 kt. Seas 6 to 10 ft. Freezing spray.
.FRI...SW wind 10 to 20 kt. Seas 4 to 8 ft.
.FRI NIGHT...S wind up to 15 kt. Seas 4 ft.
.SAT THROUGH SUN...NE wind 10 to 25 kt. Seas 4 to 8 ft.
.MON...N wind up to 20 kt. Seas 8 to 12 ft.

$$

PKZ352-260215-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
323 AM AKST Thu Jan 25 2018

.TODAY...NW wind 20 to 30 kt. Seas 11 to 15 ft. Freezing spray.
.TONIGHT...NW wind 20 to 30 kt becoming W 10 to 25 kt after
midnight. Seas 9 to 14 ft. Freezing spray.
.FRI...W wind up to 15 kt becoming SE up to 20 kt in the
afternoon. Seas 5 to 9 ft.
.FRI NIGHT...E wind up to 20 kt. Seas 6 ft.
.SAT THROUGH SUN...NE wind 10 to 25 kt. Seas 6 to 11 ft.
.MON...NW wind 10 to 20 kt. Seas 8 to 13 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
428 PM AKST Tue Jan 23 2018

.ANALYSIS AND UPPER LEVELS...
The upper level trough remains over mainland Alaska with the
ridge over the Bering Sea. Very cold temperatures as associated
with the upper level low and that will be tracking into Southwest
and Southcentral Alaska later this week. The deformation band
did set up over Southcentral Alaska late last night and has been
snowing itself out over the course of the day in the northern
Cook Inlet region and Susitna Valley. A tight pressure gradient
is set up along the north Gulf coast allowing for some gusty
outflow winds but they are limited by a lack of upper level
support. There is upper level support behind the upper trough
axis from near Kodiak Island to the Eastern Aleutians with the
tight northwest gradient aloft between the low and ridge.

&&

.MODEL DISCUSSION...
The most significant model change to address is the way the 500 mb
low center is digging into southern Alaska Wednesday night into
Thursday night. Instead of the low center moving into Bristol Bay,
the models are showing the low moving to Kodiak Island Thursday
night. The sensible change from all this is that there is a
greater chance of clouds and precipitation in Southcentral Alaska
with this low track and less chance across the Southwest mainland.

&&

.AVIATION...
PANC...Generally MVFR conditions will occur through the evening as
snow lingers in the area. It should end by late evening and allow
dry northerly winds to clear out the area by morning. While there
is always a chance of fog after a snowfall, the northerly winds
and dry airmass moving into the area should keep the fog away
leading to VFR conditions in a northerly breeze for Wednesday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The radar and the models indicate that snow flurries will likely
linger into the overnight hours until the longwave trough moves
through. That said, some of the snow bands are probably below the
radar beam and it is not out of the question for a few locations
in Anchorage and the Mat-Su Valleys to receive another inch or
two, but given the limitations of the models it is difficult to
pinpoint. Generally speaking, snow will taper off for the region.

Tomorrow cold air advection and drier conditions will impact
Southcentral. Brutally cold temperatures are projected for
Wednesday and Thursday. In the Anchorage Bowl and the Mat-Su
valleys single digit high temps are forecast. Additionally,
outflow winds continue to impact the region this forecast package
as the thermal gradient remains in place (most pronounced along
the Aleutian Range). At 925 mb north of the Aleutian Range the
temperature ranges from -20C to -28C and south of the Aleutian
Range the temperatures range from -2C to -12C. These outflow winds
will result in rough seas and strong gap flows with gale to storm
gusts for the Western Gulf marine areas through Thursday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2: Wednesday and
Thursday)...
The advance of a strong upper level low just east of the area and
its associated bitterly cold air continues across Southwest Alaska
this evening. This will leave the area with more of the same
weather: clear and cold conditions. Temperatures are running
anywhere from 15 to 25 degrees below normal area-wide. Fortunately
the winds will remain light in most areas away from the coast,
so once again any wind chill concerns should remain localized
to interior windier locations north and west of Iliamna. Towards
the coast, temperatures are slightly warmer, and so the slightly
stronger winds should still keep wind chills shy of advisory
criteria. The only precipitation concerns will be confined to
the immediate Kuskokwim Delta coast and Nunivak Island Wednesday
into Wednesday evening with a fast-moving impulse of moisture,
though any snow that falls will be light.

On Thursday, the upper level low tracks to either side of the
Alaska Range. Regardless of its final track, behind the upper
low passage a warming trend in temperatures back toward normal
is expected as we head through late week.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2: Wednesday
and Thursday)...
A broad warm ridge and associated surface high pressure centered
over the central Aleutians continues to dominate most of the
Bering's weather, except near the coast and the far western
Bering. The coast is the transition zone to deep polar air over
the state. Meanwhile out west, another very deep low out near the
Kuril Islands will build the ridge northward. The building ridge
over the Bering will very effectively block the active weather
over the far western Bering from impacting any more of the area.

Besides the occasional weak impulse of energy rapidly tracking
southbound across the eastern Bering into the Alaska Peninsula,
the remainder of the area will remain under a mix of sun and
clouds as much of the stratus erodes. Conditions will deteriorate
Thursday night into Friday over the western Bering and Aleutians
as a front moves over the area and stalls.

&&

.LONG TERM FORECAST (Days 3 through 7)...
Beginning the extended period forecast Thursday night, a deep
arctic vortex will be moving south over Kodiak Island and then
into the Western Gulf of Alaska by Friday morning. A very cold
air mass will be in place, especially over Southwest Alaska as
the cold air takes the path of least resistance around the Alaska
Range into the Bering Sea. The tricky forecast at this juncture
will be over Southcentral as the eastern periphery of the
aforementioned upper vortex will be advecting a warmer air mass
toward the coast (although still cold enough for all snow). This
will bring snow chances to all of the North Gulf Coast (and
potentially into some inland locales near the coast) and Kodiak
Island. The low quickly digs south with snow chances moving south
with the low so that by Sunday all of Southern Alaska will be dry
as cold high pressure settles in.

The high latitude blocking high is still expected to develop
somewhere over Eastern Siberia and the northwest Bering Sea which
will continue a northerly flow pattern aloft over Southern Alaska
along with continued dry and cold through Tuesday. At this
juncture, the numerical model guidance falls apart as the high
latitude block shears the mainland trough and upper level energy
splits over the North Pacific. However, this model discrepancy
really does not significantly impact the sensible weather over
the region, so expect continued cold and largely dry weather into
the midweek period.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Heavy Freezing Spray Warning 121 126 127 129 130 131 132
								136 137 138 139 141 160 180.
		 Storm Warning 130.
		 Gale Warning 120 127 131 132 138 150 178.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...PS
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JW
LONG TERM...JA