Gale Warning 4, NWS Anchorage, AK

436 
FZAK61 PAFC 070022
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
322 PM AKST Mon Jan 6 2020

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.

PKZ399-071400-
322 PM AKST Mon Jan 6 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A trough remains along the North Gulf Coast through Wed 
afternoon. A 1008 mb low at 60N 142W loops to 58N 138W at 1010 mb 
for Wed afternoon. A weakening front slides across the Southern 
Gulf by Wed afternoon. High pressure edges into the Western Gulf 
by Wed afternoon.

$$

PKZ351-071400-
Gulf of Alaska Offshore North of 57N and West of 144W-
322 PM AKST Mon Jan 6 2020

.TONIGHT...W wind 20 kt. Seas 7 ft. Freezing spray.
.TUE...W wind 10 to 25 kt. Seas 8 ft. Freezing spray.
.TUE NIGHT...W wind 15 to 25 kt. Seas 7 ft. Freezing spray.
.WED...NW wind 10 to 25 kt. Seas 6 ft.
.WED NIGHT...N wind up to 15 kt. Seas 3 to 7 ft.
.THU THROUGH SAT...S wind 15 to 30 kt. Seas 6 to 11 ft.

$$

PKZ352-071400-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
322 PM AKST Mon Jan 6 2020

.TONIGHT...W wind 10 to 20 kt. Seas 8 ft.
.TUE...W wind 10 to 20 kt. Seas 8 ft.
.TUE NIGHT...NW wind 10 to 15 kt. Seas 5 to 8 ft.
.WED...NW wind 10 to 25 kt. Seas 5 to 8 ft.
.WED NIGHT...NE wind 10 to 25 kt. Seas 5 to 10 ft.
.THU THROUGH SAT...W wind 20 to 35 kt. Seas 8 to 16 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
429 PM AKST Sun Jan 5 2020

.ANALYSIS AND UPPER LEVELS...
The 500 mb low remains over the Interior of mainland Alaska with
a westerly gradient tightening from the Kenai Peninsula southward.
This will keep the low track south of the mainland part of the
state for a while. A weak surface low just south of Cordova will
remain largely in place as it is there due to the low-level cold
advection streaming out of the coastal mountains. This is a very
typical place for a low to form and sit in this pattern.

&&

.MODEL DISCUSSION...
In the very short term, the models have suddenly come together
nicely on the low that is near the Alaska Peninsula today and
heading over Kodiak Island tonight. It was noted on the previous
discussion that this low was not resolved well on the models, but
the most recent runs look like they have converged on a likely
track they all basically agree upon. This track will bring the
low over Kodiak Island tonight with the stronger winds just east
of the Island. It will then track in a nearly straight line from
Kodiak to Yakutat keeping most of the precipitation relegated to
the north Gulf coast and not making it inland.

&&

.AVIATION...
PANC...Fog remains the big challenge around the airport and
likely will through Monday afternoon. As has been the case, it
will likely be fluctuating between periods of VFR and LIFR.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Mostly dry and cold conditions continue across the southern
mainland through mid week. Light snow will develop across Kodiak
tonight as a surface low and weak front race to the
northeast...tracking to the Northeast Gulf around midnight. Snow
from the northern Gulf will spread north to Valdez to Cordova with
a few snow showers making farther inland across the Copper River
Valley. Patchy fog along the northern Cook Inlet persists through
tonight and then should improve on Monday with mid level clouds
spreading across from the west. A short wave swings around the
base of an upper level low over the Interior on Monday which looks
to produce only a few flurries as moisture will be relatively
low. Offshore flow will increase as the upper low digs toward the
Gulf with northwesterly overhead in its wake.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...
An area of low pressure will continue to cross the Alaska
Peninsula (AKPEN) this evening, with light snow continuing.
Heading into tonight, the low will reach Kodiak around midnight,
with cyclonic flow around it allowing snow showers to continue for
the peninsula. Otherwise, high pressure will continue to
strengthen for the remainder of southwest Alaska, helping to
maintain these very cold temperatures. This cold pattern looks to
continue over the next few days, with come moderation expected on
Wednesday, as temperatures warm ahead of an approaching warm
front.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...
A pair of low pressure systems will pass just to the south and
west of Shemya over the next fews days, with each one sending a
front across the Bering and Aleutians. The first of which looks to
arrive later tonight, bringing high-end sustained gales to
locations west of the Rat Islands, reaching storm force west of
Shemya. This front moves north and east through the central Bering
and Aleutians on Tuesday, while stalling and undergoing
frontolysis (the weakening of a front), as it outruns its upper
level support to the west. A second gale force front reaches the
western Aleutians by Tuesday evening, making a little more
progress than its predecessor, having reached the north central
Bering and eastern Aleutians for wednesday evening. This second
front will also bring more of a re-newed push of warmer air with
it following frontal passage.

&&

.MARINE (Days 3 through 5: Wednesday through Friday)...

Gulf of Alaska:

A bit more activity is expected, particularly on Thursday over the
Gulf of Alaska, as a low tracking across the southern Gulf causes
widespread easterly gales over much of the Gulf, with localized
storms possible through the windier gaps and passes, and possibly
through Shelikof Strait. Otherwise, generally quiet conditions are
expected on Wednesday ahead of the low, and on Friday some
localized gales are possible through the Barren Islands, but
conditions should be quieting down and improving as high pressure
builds.

Bering Sea:

A very active period is expected across the Bering. On Wednesday a
low approaching the western Aleutians may produce gales in that
area, mainly on the Pacific side of the islands. Its leading front
will spread gales across the central Bering Wednesday morning, and
will gradually dissipate was it moves to the eastern Bering
Wednesday evening. The trailing front crosses the central
Aleutians Wednesday night, which may produce a few gales in that
area. The low will rapidly weaken as a much stronger one follows
behind it from the North Pacific. Storm force winds are possible
with the low, specifically through the central Aleutians
(Adak/Atka) Thursday night. Then on Friday morning the storms
shift westward as the low center tracks over the western
Aleutians, just east of Shemya. Meanwhile the leading front will
produce widespread gales over much of the rest of the Bering
through Friday. Storms on westerly winds will wrap around the
south side of the low over the western Bering and Aleutians
through Friday night.

&&

.LONG TERM FORECAST (Days 3 through 7: Wednesday through Sunday)...

The main theme of the long-term forecast will be a warming trend
in the temperatures. The arctic cold air mass over much of the
mainland will begin to shift eastward into Canada, as the storm
track moves into the Bering. This will allow a series of lows and
associated fronts to move into the Bering which will slowly but
surely dislodge the cold air in place over mainland Alaska,
especially over Southwest Alaska.

Starting on Wednesday, a weakening, fully occluded low will
meander across the western Aleutians, as its leading front moves
into the eastern Bering. Cloud cover and a few snow showers are
possible Wednesday night into Thursday along the coast, but the
front will be largely dissipated, so any threats of snow will be
low. A secondary triple point low will develop south of the Alaska
Peninsula Wednesday night, which will track east across the
southern Gulf on Thursday. Impacts should largely be confined to
the Kodiak Island area, as the track keeps any snow further south.
The cold air in place across Southcentral should be pulled south
into the Gulf behind the low, so the gap winds will likely be
strong on Thursday.

Another much more powerful low will move into the western
Aleutians Thursday night into Friday, causing widespread gales and
storms across the chain. There is some difference in the track of
the low in the models, but all are expecting the center of a
strong low to be over the western Aleutians east of Shemya by
Friday morning. The low will continue intensifying as it moves
north of the chain through the day, thus storm force winds are
likely across all of the western Aleutians during the day Friday.
Its leading front will move into Southwest Alaska Friday night,
with an air mass warm enough that rain may not be out of the
question, especially along the coast. The front moves inland on
Saturday, with mixed precipitation or snow possible all across
Southwest Alaska. A triple-point low will develop over the western
Gulf Saturday evening, but where this low develops is highly
uncertain. Its development and the strength of the front will
determine how much, if any, moisture makes it over the Alaska
range to affect the Cook Inlet region Saturday night into Sunday.
The models all agree that the Arctic air mass will persist over
the Copper River Basin through Sunday, so expect the gap winds,
particularly through Thompson Pass and the Copper River Delta, to
remain elevated.

Even if the front dissipates before any moisture reaches
Southcentral, the much warmer air mass and cloud cover are
expected to make it into the Cook Inlet region. This will
allow temperatures to return at least to normal (20s for highs,
teens for lows), if not warmer this weekend. Meanwhile,
temperatures returning to normal could happen in Southwest Alaska
as early as Friday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Storm Warning 178.
 Gale Warning 174 176 177.
 Heavy Freezing Spray 121 127 129 130 139 185.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...KH
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
MARINE/LONG TERM...JW