Gale Warning 341, NWS Anchorage, AK

Issued

Apr 25, 2018, 3:29 PM AKDT (23:29 UTC)

Expired

Apr 26, 2018, 4:00 AM AKDT

In force

13 hr

Issued by

NWS Anchorage, AK

182 
FZAK52 PAFC 252329
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
329 PM AKDT Wed Apr 25 2018

Coastal Waters Forecast for Southwest Alaska+Bristol Bay+The
Alaska Peninsula Waters and the Aleutian Islands up to 100 nm out.

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.

PKZ199-261200-
329 PM AKDT Wed Apr 25 2018
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
A front over the far eastern Bering dissipates tonight. A second
front enters the western Bering early Thu morning, reaching the
eastern Bering Thu night...then moves into mainland Alaska. A 982
mb low 375 nm southwest of Saint Matthew Island Fri morning moves
to 225 nm southwest of Saint Matthew Island Fri afternoon at 984 
mb. Its associated front moves into the western Bering late Thu 
afternoon and reaches the far eastern Aleutians by Fri afternoon.

$$

PKZ150-261200-
South of the AK Peninsula Sitkinak to Castle Cape-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 14 ft.
.THU...SW wind 20 kt. Seas 11 ft.
.THU NIGHT...SW wind 20 kt increasing to 30 kt after midnight.
Seas 9 ft.
.FRI...SW wind 30 kt. Seas 10 ft.
.FRI NIGHT...SW wind 35 kt. Seas 13 ft.
.SAT...SW wind 30 kt. Seas 15 ft.
.SUN...SW wind 20 kt. Seas 12 ft.
.MON...SW wind 15 kt. Seas 9 ft.

$$

PKZ155-261200-
South of the AK Peninsula Castle Cape to Cape Sarichef-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 16 ft.
.THU...W wind 20 kt. Seas 11 ft.
.THU NIGHT...SW wind 30 kt. Seas 10 ft.
.FRI...SW wind 30 kt. Seas 11 ft.
.FRI NIGHT...SW wind 40 kt. Seas 16 ft.
.SAT...SW wind 30 kt. Seas 16 ft.
.SUN THROUGH MON...S wind 20 kt. Seas 12 ft.

$$

PKZ160-261200-
Bristol Bay-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THURSDAY NIGHT...

.TONIGHT...S wind 15 kt. Seas 7 ft.
.THU...SW wind 15 kt. Seas 5 ft.
.THU NIGHT...S wind 30 kt. Seas 9 ft. Snow.
.FRI...SW wind 20 kt. Seas 9 ft.
.FRI NIGHT...S wind 25 kt. Seas 8 ft.
.SAT...SW wind 25 kt. Seas 8 ft.
.SUN THROUGH MON...S wind 15 kt. Seas 7 ft.

$$

PKZ165-261200-
Port Heiden to Cape Sarichef-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 9 ft.
.THU...SW wind 15 kt increasing to 25 kt in the afternoon. 
Seas 7 ft.
.THU NIGHT...SW wind 30 kt. Seas 11 ft. Rain and snow.
.FRI AND FRI NIGHT...SW wind 35 kt. Seas 13 ft.
.SAT...SW wind 25 kt. Seas 13 ft.
.SUN THROUGH MON...S wind 20 kt. Seas 11 ft.

$$

PKZ170-261200-
Cape Sarichef to Nikolski Bering Side-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...W wind 20 kt. Seas 9 ft.
.THU...SW wind 25 kt. Seas 8 ft.
.THU NIGHT...SW wind 30 kt. Seas 11 ft.
.FRI...S wind 40 kt. Seas 15 ft.
.FRI NIGHT...SW wind 30 kt. Seas 15 ft.
.SAT...SW wind 30 kt. Seas 14 ft.
.SUN THROUGH MON...S wind 20 kt. Seas 12 ft.

$$

PKZ171-261200-
Unalaska Bay-
329 PM AKDT Wed Apr 25 2018

.TONIGHT...W wind 20 kt. Seas 3 ft. Rain showers.
.THU...W wind 15 kt. Seas 2 ft.
.THU NIGHT...SW wind 20 kt. Seas 3 ft.
.FRI AND FRI NIGHT...SW wind 30 kt. Seas 5 ft.
.SAT...SW wind 25 kt. Seas 3 ft.
.SUN THROUGH MON...S wind 15 kt. Seas 2 ft.

$$

PKZ172-261200-
Cape Sarichef to Nikolski Pacific Side-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...W wind 20 kt. Seas 14 ft.
.THU...W wind 20 kt. Seas 10 ft.
.THU NIGHT...SW wind 25 kt. Seas 9 ft.
.FRI AND FRI NIGHT...SW wind 40 kt. Seas 16 ft.
.SAT...SW wind 35 kt. Seas 15 ft.
.SUN THROUGH MON...SW wind 20 kt. Seas 12 ft.

$$

PKZ173-261200-
Nikolski to Seguam Island Bering Side-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 10 ft.
.THU...SW wind 25 kt. Seas 9 ft.
.THU NIGHT...SW wind 30 kt. Seas 10 ft.
.FRI...SW wind 40 kt. Seas 15 ft.
.FRI NIGHT...SW wind 30 kt. Seas 15 ft.
.SAT...SW wind 35 kt. Seas 13 ft.
.SUN THROUGH MON...SW wind 20 kt. Seas 12 ft.

$$

PKZ174-261200-
Nikolski to Seguam Island Pacific Side-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...W wind 20 kt. Seas 12 ft.
.THU...W wind 25 kt. Seas 10 ft.
.THU NIGHT...SW wind 25 kt. Seas 9 ft.
.FRI...SW wind 40 kt. Seas 17 ft.
.FRI NIGHT...SW wind 30 kt. Seas 17 ft.
.SAT...SW wind 35 kt. Seas 16 ft.
.SUN THROUGH MON...SW wind 20 kt. Seas 13 ft.

$$

PKZ175-261200-
Seguam Island to Adak Bering Side-
329 PM AKDT Wed Apr 25 2018

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 10 ft.
.THU...W wind 25 kt. Seas 10 ft.
.THU NIGHT...SW wind 25 kt becoming S 40 kt after midnight. 
Seas 10 ft. Rain.
.FRI...SW wind 40 kt. Seas 14 ft.
.FRI NIGHT...SW wind 30 kt. Seas 14 ft.
.SAT...SW wind 35 kt. Seas 11 ft.
.SUN THROUGH MON...SW wind 20 kt. Seas 12 ft.

$$

PKZ176-261200-
Seguam Island to Adak Pacific Side-
329 PM AKDT Wed Apr 25 2018

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 11 ft.
.THU...W wind 25 kt. Seas 9 ft.
.THU NIGHT...SW wind 25 kt becoming S 35 kt after midnight. 
Seas 11 ft. Rain.
.FRI...SW wind 40 kt. Seas 17 ft.
.FRI NIGHT...SW wind 30 kt. Seas 16 ft.
.SAT...SW wind 35 kt. Seas 17 ft.
.SUN THROUGH MON...SW wind 20 kt. Seas 14 ft.

$$

PKZ177-261200-
Adak to Kiska-
329 PM AKDT Wed Apr 25 2018

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 10 ft.
.THU...W wind 30 kt. Seas 10 ft.
.THU NIGHT...S wind 40 kt. Seas 10 ft building to 16 ft after
midnight. Rain.
.FRI...SW wind 35 kt. Seas 17 ft.
.FRI NIGHT...SW wind 30 kt. Seas 16 ft.
.SAT...SW wind 30 kt. Seas 15 ft.
.SUN THROUGH MON...SW wind 25 kt. Seas 15 ft.

$$

PKZ178-261200-
Kiska to Attu-
329 PM AKDT Wed Apr 25 2018

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...SW wind 30 kt. Seas 10 ft.
.THU...SW wind 30 kt. Seas 10 ft. Rain.
.THU NIGHT...S wind 40 kt. Seas 17 ft. Rain.
.FRI...SW wind 35 kt. Seas 18 ft.
.FRI NIGHT...SW wind 30 kt. Seas 16 ft.
.SAT...SW wind 30 kt. Seas 18 ft.
.SUN THROUGH MON...SW wind 25 kt. Seas 18 ft.

$$

PKZ179-261200-
Pribilof Islands Near Shore Waters-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...W wind 20 kt. Seas 8 ft.
.THU...SW wind 30 kt. Seas 11 ft. Snow.
.THU NIGHT...W wind 25 kt. Seas 12 ft.
.FRI...S wind 35 kt. Seas 14 ft.
.FRI NIGHT...SW wind 30 kt. Seas 14 ft.
.SAT...SW wind 25 kt. Seas 14 ft.
.SUN THROUGH MON...S wind 20 kt. Seas 12 ft.

$$

PKZ180-261200-
Kuskokwim Delta and Etolin Strait-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 8 ft.
.THU...S wind 25 kt. Seas 7 ft.
.THU NIGHT...S wind 30 kt. Seas 10 ft. Snow.
.FRI...SW wind 25 kt. Seas 10 ft.
.FRI NIGHT...S wind 30 kt. Seas 11 ft.
.SAT...SW wind 25 kt. Seas 10 ft.
.SUN THROUGH MON...S wind 20 kt. Seas 9 ft.

$$

PKZ181-261200-
North and West of Nunivak Island-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 8 ft.
.THU...S wind 25 kt. Seas 8 ft. Widespread snow showers.
.THU NIGHT...SW wind 25 kt. Seas 8 ft.
.FRI...S wind 25 kt. Seas 8 ft.
.FRI NIGHT...SE wind 25 kt. Seas 8 ft.
.SAT...W wind 20 kt. Seas 9 ft.
.SUN...S wind 25 kt. Seas 9 ft.
.MON...S wind 20 kt. Seas 8 ft.

$$

PKZ185-261200-
Saint Matthew Island Waters-
329 PM AKDT Wed Apr 25 2018

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 9 ft.
.THU...SW wind 25 kt. Seas 10 ft. Snow.
.THU NIGHT...W wind 25 kt. Seas 9 ft.
.FRI...SE wind 25 kt. Seas 8 ft.
.FRI NIGHT...NE wind 25 kt. Seas 10 ft.
.SAT...NE wind 20 kt. Seas 10 ft.
.SUN...SW wind 20 kt. Seas 9 ft.
.MON...S wind 15 kt. Seas 9 ft.

$$

NWS Anchorage, AK wrote its last area forecast discussion before this gale warning went out at Apr 25, 4:51 AM AKDT, 10 hours 38 minutes earlier.

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
451 AM AKDT Wed Apr 25 2018

.ANALYSIS AND UPPER LEVELS...
The upper level pattern this morning consists of a very large
upper level low centered over the northern Bering but extending
south across the Aleutians and well into the North Pacific.
Eastern portions of the upper low have pushed into Western Alaska
with a cold airmass aloft and strong southwesterly flow bringing
cool showery conditions to Southwest Alaska. In Southcentral
Alaska, the frontal system moving through yesterday and last night
has exited the area to the north and east with most areas
switching over to scattered showers though precipitation lingering
the longest along the northern Gulf Coast. As the cold advection
over Southwest Alaska spreads east, so do the more abundant
showers, with showers starting to pick up again in Southcentral
Alaska particularly over and along the mountains.

&&

.MODEL DISCUSSION...
Models remain in good synoptic agreement through the end of the
week with high resolution models preferred for better details.
Some small model differences start to become apparent in the
handling of the trough crossing southern Alaska on Friday
regarding its strength and exact tracks as well as with the speed
of larger frontal system following it in from the west Friday
night and Saturday.

&&

.AVIATION...
PANC...Predominantly VFR conditions and breezy southeasterly
winds will persist for the next couple of days. Scattered showers
around the area may briefly drop conditions to MVFR with heavier
showers possibly being mixed with snow at times.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The mean position of the upper long wave trough continues over
western Alaska/eastern Bering Sea through Thursday night. This
will continue broad southwesterly flow and allow embedded upper
short waves to move across Southcentral. Air aloft continues to
cool aloft through Thursday bringing relatively unstable
conditions. That said, expect showery weather to prevail across
much of Southcentral. Precipitation type will be somewhat
problematic as wet bulb zero heights (snow levels) will be fairly
low during the morning hours inland before rising in the
afternoon. So expect generally showers to be mainly rain along the
coasts with a mix inland to all snow at higher elevation and
northern valley sections.

Surface pressure gradients should remain strong enough to continue
small craft winds over much of the western Gulf/Cook Inlet region
through today. In addition, gap flows will continue across
Turnagain Arm, out of the Knik River Valley, and along the Copper
River Basin into Thursday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Unseasonably cool and wet weather will plague southwest Alaska
through the forecast period as an upper level low remains in place
over the Bering. The low center will shift slightly north today
leading to persistent southwesterly onshore flow which will
promote widespread rain showers across the region. A shortwave
trough rotating around the base of the upper low will move up into
the Bristol Bay area this afternoon leading to a period of
enhanced shower activity over the Bristol Bay coast and up through
the Kuskokwim River Valley. In fact, some of these showers may
become more deeply convective in nature as limited surface
heating combined with cold air aloft will lead to steep mid level
lapse rates and decent instability in the afternoon. Hi-res models
show a line of enhanced showers forming from a line between King
Salmon, Iliamna, and Sparrevohn this afternoon, thus embedded
isolated thunderstorms may be possible in this area.

Shower activity will taper off some Wednesday night and Thursday
morning before a low dropping south across the northern Bering
brings another round of precipitation and gusty southwest winds
late Thursday night through Friday afternoon. Colder air
associated with this system as well as plenty of antecedent cold
air at the surface should keep precipitation as snow for most
locations, though accumulations only look to be minimal at this
time.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A broad upper low over the Bering will shift slightly north and
east today keeping the eastern half of the Bering/Aleutians under
cool and showery conditions while a shortwave ridge builds in over
the western half of the area bringing drier weather to places
like Shemya and Adak. On Thursday, a shortwave trough dropping
south over the central Bering will sweep across the Pribilofs and
eastern Bering bringing snow changing over to rain by Thursday
evening. The next major system comes barreling across the Pacific
towards the western Bering/Aleutians by Thursday afternoon
bringing gale force winds and heavy rain across the island chain
as it progresses east through the end of the week.

&&

.LONG TERM FORECAST (Days 3 through 7)...
The long range forecast beginning Thursday night continues with
higher precipitation chances across the southern mainland as an
upper level Bering low and associated surface front lifts north of
the Bering Strait through Saturday. The next storm system quickly
follows as a fast paced low tracks across the Bering, making it
to the Southwest coast by Saturday morning.

Models have been struggling with evolving the individual low
tracks as the jet stream acts as a 110+ kt conveyor belt which
remains along the Aleutian Chain and southern Gulf through early
next week. Models are starting to align better with breaking the
ridge down over the Gulf over the latter part of the weekend.
However, this is a new trend for the forecast at the start of next
week. Main updates for the extended forecast focus around
stronger winds along the Bering and trends toward higher
precipitation chances for the southern mainland and surrounding
waters.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

SYNOPSIS AND MODEL DISCUSSION...JER
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KV
LONG TERM...KH

Gale Warnings in Alaska, 2018Every gale warning in 2018

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text.