Gale Warning 558, NWS Anchorage, AK

166 
FZAK61 PAFC 171142
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
342 AM AKDT Mon Oct 17 2022

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.

PKZ399-180100-
342 AM AKDT Mon Oct 17 2022
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A series of fronts move across the Gulf of Alaska through Mon 
evening. A 960 mb N Pacific low moves to 54N 148W Tue evening and
then to 58N 144W at 978 mb Wed morning.

$$

PKZ351-180100-
Gulf of Alaska Offshore North of 57N and West of 144W-
342 AM AKDT Mon Oct 17 2022

...STORM WARNING TUESDAY...

.TODAY...S wind 20 kt. Seas 8 ft.
.TONIGHT...SE wind 15 to 25 kt. Seas 8 ft. Rain.
.TUE...E wind 25 to 40 kt increasing to 35 to 50 kt in the
afternoon. Seas 8 to 13 ft building to 15 to 19 ft in the
afternoon. Rain.
.TUE NIGHT...E wind 30 to 45 kt. Seas 16 to 30 ft.
.WED...W wind 30 to 45 kt. Seas 13 to 21 ft.
.THU THROUGH FRI...W wind 20 to 35 kt. Seas 10 to 13 ft.

$$

PKZ352-180100-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
342 AM AKDT Mon Oct 17 2022

...STORM WARNING TUESDAY...

.TODAY...SW wind 25 kt diminishing to 10 to 20 kt in the
afternoon. Seas 9 ft.
.TONIGHT...SE wind up to 20 kt becoming E 25 to 40 kt after
midnight. Seas 7 to 11 ft. Rain.
.TUE...E wind 35 to 50 kt. Seas 12 to 20 ft building to 18 to 28
ft in the afternoon. Rain.
.TUE NIGHT...NW wind 35 to 50 kt. Seas 17 to 31 ft.
.WED...SW wind 30 to 45 kt. Seas 14 to 22 ft.
.THU THROUGH FRI...W wind 25 to 35 kt. Seas 10 to 15 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
444 AM AKDT Sun Oct 16 2022

.ANALYSIS AND UPPER LEVELS...

Broad low pressure system sits nearly stationary near the
Kuskokwim Delta today and tomorrow before dropping south to merge
with a low in the North Pacific. Associated longwave troughing
extends into the central Bering and the Gulf of Alaska. Upper
level riding over Canada clips into the Copper River Basin today,
getting shoved off to the northeast as troughing moves north from
the Gulf of Alaska. Another high pressure ridge sets up over the
western Bering and will linger through Monday evening.

Radar shows rain filling in across portions of Southcentral and
Southwest Alaska tonight. Other observations show freezing
precipitation further inland for places like the Kuskokwim Valley
and Kuskokwim Delta near Bethel, as well as in the Copper River
Basin.

Two larger systems are developing, one over Russia and one in the
North Pacific. Both will have some impact over Southern Alaska
towards mid-week.

&&

.MODEL DISCUSSION...

Models are in good overall synoptic agreement through the short
term. Which the general consensus at the surface is better, there
are still some minute issues, mainly with precipitation and
tracking of the shortwaves. Models seem to have a pretty good
handle on the two larger systems, one over Russia and one over the
North Pacific, as they work their way towards the Bering Sea and
Gulf of Alaska respectively.

&&

.AVIATION...
PANC...Light rain will continue. Expect periods of MVFR-IFR
conditions throughout much of the day today.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3;
Today through Tuesday night)...

A surface low south of Cordova this morning will move over Prince
William Sound then weaken rapidly as it moves inland by Sunday
afternoon. A widespread area of precipitation stretching from
Prince William Sound and the southern Copper River Basin to the
Susitna Valley will lift northeast across the region today as the
aforementioned low and associated upper-level shortwave move
toward the Copper River Basin. Along the coast and over the Mat-
Su Valleys and Anchorage Bowl, the precipitation is falling mainly
as rain. For the Copper River Basin, however, the precipitation
continues to fall as wintry mix, with snow in the western half of
the basin and a mix of snow, sleet, and freezing rain from the
Richardson Highway east. The frozen precipitation over this area
will wind down by late morning as southerly winds increase and
temperatures finally climb above freezing.

A series of shortwaves and surface troughs will continue to move
north across the Gulf of Alaska in the wake of this initial
system. These features will keep conditions unsettled late Sunday
through Monday. with a steady rain along the coast and periodic
waves of showers inland. With the persistent southerly flow
aloft, temperatures across much of Southcentral will stay above
the freezing mark. This will mean much of the precipitation that
falls from Sunday night through Monday is expected to fall as
rain, with the exception of locations along the northern Susitna
Valley and Copper River Basin as well as higher elevations.

Attention then shifts back to the southern Gulf for Tuesday as a
potent storm system lifts north from the Pacific. A front will
swing out ahead of the center of circulation, likely bringing
strong winds and heavy rain to Kodiak Island by Tuesday
afternoon. The front is expected to continue north to the
Southcentral coast by Tuesday night. There remains a bit of
uncertainty as to how far inland the front advances for
Wednesday as the northern extent of precipitation. Right now,
this system looks to weaken quickly as it takes a more eastward
track toward Yakutat for Wednesday afternoon.

&&.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Today
through Tuesday)...

A broad low pressure system extends across the eastern Aleutians
and southern Alaska Peninsula. Upper level shortwaves rotating on
the eastern side of the low is moving northward with rain across
Bristol Bay. A surge of warm, moist air has slowly changed the
precipitation type from wintry mix to all rain in the Kuskokwim
Delta. Not much changes are expected with precipitation
continuing through Monday afternoon/evening as the broad low
remains quasi- stationary. By Monday night, the low will weaken
and lift northward in response to a Bering Sea high pressure
system shifting eastward. Precipitation will then taper off as the
high builds overhead with cool, dry conditions returning on
Tuesday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3:
Today through Tuesday)...

A broad low pressure system extends across the eastern Aleutians
and southern Alaska Peninsula. Small craft northerly winds along
with scattered rain/snow showers continues across the Bering Sea
and Aleutian Chain as cold air streams over the relatively warm
sea waters on the back side of the low. Winds are expected to
diminish along with precipitation tapering off by Monday night as
a ridge of high pressure builds overhead. Meanwhile, a front
extending ahead of a strong low in the Sea of Okhotsk will advance
eastward. This front has the potential to bring storm force
southerly winds into the western Aleutians and Bering Sea between
Monday and Tuesday.

&&
.LONG TERM FORECAST (Days 4 through 7: Wednesday through
Saturday)...

There is reasonably good consensus with the models most of this
forecast period. Confidence continues to increase regarding the
low tracking into the Gulf Of Alaska Tuesday-Wednesday. This low
contains the remnants of a former tropical system. All the global
models have a tight pressure gradient, expect strong (gale to
hurricane force) winds and enhanced seas with this low. Heavy
precipitation is anticipated along the northern Gulf coast. There
is a second system that will sweep across the Bering and Aleutians
with the front near Cold Bay Wednesday morning. Expect gale force
winds and precipitation. This front will weaken as it approaches
the Southwest Alaska coast. Cyclonic flow will impact the Bering
through day 6 and by Saturday the models are out of phase. It is
also worth mentioning that temperatures will be warmer than
normal. A number of locations in Southcentral, including Anchorage
and Palmer will see afternoon temperatures in the mid to upper
40s.

&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 141
MARINE...NONE.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...KM
SOUTHCENTRAL ALASKA...TM
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MF
LONG TERM...PJS