Gale Warning 500, NWS Anchorage, AK

901 
FZAK51 PAFC 042312
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
312 PM AKDT Wed Oct 4 2017

Coastal Waters Forecast for the Northern Gulf of Alaska Coast
up to 100 nm out including Kodiak Island and Cook Inlet.

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.

PKZ197-051145-
312 PM AKDT Wed Oct 4 2017
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A strong front will enter the western Gulf tonight then move to 
the eastern Gulf Thu afternoon. A 990 mb low will develop along 
the front 40 nm south of Seward Thu morning then move inland near 
Valdez Thu afternoon. A trough of low pressure will remain over the 
northern Gulf Thu through Fri. 

$$

PKZ119-051145-
Cape Suckling to Cape Cleare-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY AND THURSDAY NIGHT...

.TONIGHT...S wind 15 kt increasing to 25 kt after midnight. Seas
8 ft. Rain.
.THU...S wind 30 kt increasing to 40 kt in the afternoon. Seas
13 ft. Rain.
.THU NIGHT...W wind 35 kt. Seas 15 ft.
.FRI...W wind 30 kt. Seas 17 ft.
.FRI NIGHT...NW wind 20 kt. Seas 17 ft.
.SAT...W wind 20 kt. Seas 15 ft.
.SUN THROUGH MON...SE wind 15 kt. Seas 6 ft.

$$

PKZ120-051145-
Cape Cleare to Gore Point-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY AND THURSDAY NIGHT...

.TONIGHT...Variable wind 10 kt becoming S 20 kt after midnight.
Seas 7 ft. Rain.
.THU...S wind 30 kt becoming W 40 kt in the afternoon. Seas 12 ft.
Rain.
.THU NIGHT...W wind 35 kt. Seas 15 ft.
.FRI...W wind 40 kt. Seas 16 ft.
.FRI NIGHT...W wind 35 kt. Seas 15 ft.
.SAT...W wind 30 kt. Seas 13 ft.
.SUN...S wind 15 kt. Seas 6 ft.
.MON...Variable wind 10 kt. Seas 7 ft.

$$

PKZ121-051145-
Resurrection Bay-
312 PM AKDT Wed Oct 4 2017

.TONIGHT...S wind 15 kt. Seas 3 ft. Rain.
.THU...S wind 20 kt becoming N 15 kt in the afternoon. Seas 4 ft.
Rain.
.THU NIGHT...S wind 10 kt becoming N after midnight. Seas 2 ft.
.FRI AND FRI NIGHT...N wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...N wind 15 kt. Seas 3 ft.
.MON...N wind 20 kt. Seas 4 ft.

$$

PKZ125-051145-
Prince William Sound-
312 PM AKDT Wed Oct 4 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TONIGHT...SE wind 10 kt increasing to 25 kt after midnight. Seas
2 ft building to 4 ft after midnight. Rain showers.
.THU...E wind 30 kt. Seas 4 ft building to 7 ft in the afternoon.
Rain.
.THU NIGHT...W wind 20 kt. Seas 4 ft.
.FRI AND FRI NIGHT...NW wind 10 kt. Seas 2 ft.
.SAT...NW wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...E wind 10 kt. Seas 2 ft.

$$

PKZ126-051145-
Port Valdez-
312 PM AKDT Wed Oct 4 2017

.TONIGHT...Variable wind less than 10 kt. Seas 2 ft. Rain showers.
.THU...W wind 10 kt. Seas 2 ft. Rain.
.THU NIGHT...Variable wind less than 10 kt. Seas 2 ft. Rain.
.FRI...Variable wind less than 10 kt. Seas 2 ft.
.FRI NIGHT...E wind 10 kt. Seas 2 ft.
.SAT...NE wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ127-051145-
Valdez Narrows-
312 PM AKDT Wed Oct 4 2017

.TONIGHT...NE wind 15 kt. Seas 3 ft. Rain showers.
.THU...SW wind 15 kt. Seas 3 ft. Rain.
.THU NIGHT...NE wind 15 kt diminishing to 10 kt after midnight.
Seas 3 ft. Rain.
.FRI...NE wind 15 kt. Seas 3 ft.
.FRI NIGHT...NE wind 20 kt. Seas 3 ft.
.SAT...NE wind 20 kt. Seas 3 ft.
.SUN THROUGH MON...NE wind 10 kt. Seas 2 ft.

$$

PKZ128-051145-
Valdez Arm-
312 PM AKDT Wed Oct 4 2017

.TONIGHT...NE wind 10 kt. Seas 2 ft. Rain showers.
.THU...SW wind 15 kt. Seas 3 ft. Rain.
.THU NIGHT...Variable wind 10 kt. Seas 2 ft. Rain.
.FRI...NE wind 10 kt. Seas 2 ft.
.FRI NIGHT...NE wind 15 kt. Seas 3 ft.
.SAT...NE wind 15 kt. Seas 3 ft.
.SUN THROUGH MON...NE wind 10 kt. Seas 2 ft.

$$

PKZ129-051145-
Passage Canal-
312 PM AKDT Wed Oct 4 2017

.TONIGHT...E wind 10 kt increasing to 15 kt after midnight. Seas
2 ft. Rain.
.THU...E wind 20 kt becoming Variable wind 15 kt in the afternoon.
Seas 3 ft. Rain.
.THU NIGHT...W wind 15 kt in the evening becoming variable less
than 10 kt. Seas 2 ft.
.FRI...W wind 10 kt. Seas 2 ft.
.FRI NIGHT...W wind 15 kt. Seas 2 ft.
.SAT...W wind 10 kt. Seas 2 ft.
.SUN...E wind 15 kt. Seas 2 ft.
.MON...E wind 10 kt. Seas 2 ft.

$$

PKZ130-051145-
West of Barren Islands including Kamishak Bay-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING TONIGHT AND THURSDAY NIGHT...

.TONIGHT...SE wind 20 kt increasing to 40 kt after midnight. Seas
5 ft building to 12 ft after midnight. Rain.
.THU...SW wind 25 kt. Seas 8 ft.
.THU NIGHT...SW wind 30 kt becoming W 40 kt after midnight. Seas
11 ft.
.FRI...W wind 40 kt. Seas 12 ft.
.FRI NIGHT...W wind 35 kt. Seas 9 ft.
.SAT...W wind 30 kt. Seas 8 ft.
.SUN...Variable wind 10 kt. Seas 3 ft.
.MON...NW wind 20 kt. Seas 5 ft.

$$

PKZ131-051145-
Barren Islands East-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY AND THURSDAY NIGHT...

.TONIGHT...S wind 30 kt. Seas 6 ft building to 10 ft after
midnight. Rain.
.THU...SW wind 35 kt. Seas 11 ft.
.THU NIGHT...W wind 40 kt. Seas 16 ft.
.FRI AND FRI NIGHT...W wind 40 kt. Seas 15 ft.
.SAT...W wind 35 kt. Seas 12 ft.
.SUN...SW wind 15 kt. Seas 6 ft.
.MON...W wind 20 kt. Seas 10 ft.

$$

PKZ132-051145-
Marmot Island to Sitkinak-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...S wind 25 kt increasing to 35 kt after midnight. Seas
7 ft building to 12 ft after midnight. Rain.
.THU...W wind 35 kt. Seas 13 ft.
.THU NIGHT...W wind 45 kt. Seas 19 ft.
.FRI...W wind 40 kt. Seas 19 ft.
.FRI NIGHT...W wind 35 kt. Seas 14 ft.
.SAT...W wind 25 kt. Seas 10 ft.
.SUN...SW wind 20 kt. Seas 7 ft.
.MON...W wind 20 kt. Seas 11 ft.

$$

PKZ136-051145-
Chiniak Bay-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...S wind 20 kt increasing to 30 kt after midnight. Seas
4 ft. Rain.
.THU...SW wind 25 kt. Seas 4 ft.
.THU NIGHT...W wind 30 kt increasing to 40 kt after midnight. Seas
4 ft building to 7 ft after midnight.
.FRI...W wind 35 kt. Seas 7 ft.
.FRI NIGHT...W wind 30 kt. Seas 5 ft.
.SAT...W wind 20 kt. Seas 3 ft.
.SUN...SW wind 10 kt. Seas 2 ft.
.MON...W wind 15 kt. Seas 2 ft.

$$

PKZ137-051145-
Marmot Bay-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...SE wind 25 kt. Seas 3 ft building to 7 ft after
midnight. Rain.
.THU...W wind 30 kt. Seas 6 ft.
.THU NIGHT...W wind 30 kt increasing to 40 kt after midnight. Seas
8 ft.
.FRI...W wind 35 kt. Seas 8 ft.
.FRI NIGHT...W wind 30 kt. Seas 7 ft.
.SAT...W wind 20 kt. Seas 4 ft.
.SUN...SW wind 10 kt. Seas 2 ft.
.MON...W wind 15 kt. Seas 2 ft.

$$

PKZ138-051145-
Shelikof Strait-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY AND THURSDAY NIGHT...

.TONIGHT...S wind 25 kt. Seas 5 ft. Rain.
.THU...SW wind 35 kt. Seas 10 ft.
.THU NIGHT...SW wind 40 kt. Seas 12 ft.
.FRI...W wind 35 kt. Seas 10 ft.
.FRI NIGHT...W wind 30 kt. Seas 9 ft.
.SAT...W wind 20 kt. Seas 7 ft.
.SUN...SW wind 15 kt. Seas 5 ft.
.MON...NW wind 15 kt. Seas 4 ft.

$$

PKZ139-051145-
Cook Inlet Kalgin Island to Point Bede-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING TONIGHT AND THURSDAY NIGHT...

.TONIGHT...S wind 20 kt increasing to 35 kt after midnight. Seas
5 ft building to 8 ft after midnight. Rain.
.THU...S wind 30 kt. Seas 7 ft. Rain.
.THU NIGHT...SW wind 35 kt. Seas 10 ft.
.FRI...W wind 30 kt. Seas 7 ft.
.FRI NIGHT...W wind 25 kt. Seas 5 ft.
.SAT...W wind 25 kt. Seas 5 ft.
.SUN...N wind 10 kt. Seas 2 ft.
.MON...N wind 15 kt. Seas 3 ft.

$$

PKZ140-051145-
Cook Inlet North of Kalgin Island-
312 PM AKDT Wed Oct 4 2017

...SMALL CRAFT ADVISORY THURSDAY NIGHT...

.TONIGHT...S wind 20 kt diminishing to 10 kt after midnight. Seas 5 
ft subsiding to 3 ft. Rain.
.THU...E wind 10 kt becoming S 20 kt in the afternoon. Seas 3 ft
building to 5 ft in the afternoon. Rain.
.THU NIGHT...SW wind 30 kt. Seas 7 ft.
.FRI AND FRI NIGHT...SW wind 15 kt. Seas 4 ft.
.SAT...SW wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...N wind 10 kt. Seas 3 ft.

$$

PKZ141-051145-
Kachemak Bay-
312 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...S wind 15 kt increasing to SE 25 kt after midnight. Seas 
2 ft building to 5 ft after midnight. Rain.
.THU...SW wind 25 kt. Seas 7 ft. Rain.
.THU NIGHT...SW wind 25 kt becoming W 35 kt after midnight. Seas 7 
ft building to 11 ft after midnight.
.FRI...W wind 30 kt. Seas 10 ft.
.FRI NIGHT...W wind 25 kt. Seas 8 ft.
.SAT...W wind 20 kt. Seas 5 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.
.MON...NW wind 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
454 PM AKDT Tue Oct 3 2017

.ANALYSIS AND UPPER LEVELS...

The large scale pattern features a trough over the western part of
the state extending well south into the northern Pacific. At the
base of the trough lies a weakening vertically stacked low that is
opening into a wave this afternoon. Downstream of the trough a
ridge holds steady over western Canada. The upstream trough is
just starting to acquire a slight negative tilt as it banks up
against the base of the ridge to the east. Between the two upper
level features, an atmospheric river continues to pump subtropical
moisture to the northeast Gulf coast. Radar imagery shows the
western fringe of this moisture, currently over eastern Prince
William Sound, spreading west this afternoon toward Southcentral.

Further west, showers over the Kuskokwim Delta associated with a
departing low are just starting to weaken this afternoon. A strong
jet streak aloft and rather impressive low-level baroclinicity
associated with a surface front over the western Aleutians is
priming the western Bering for the development of a strong low
this evening. This low will be the main weather-maker over the
coming days.

&&

.MODEL DISCUSSION...
The models remain in general synoptic agreement. However, there
are some minor differences in timing and intensity with the low
and associated front tracking through the Bering/Aleutians today
through Wednesday. It seems reasonable as the two main features
which affect Alaska develop under fairly strong upper jets. The
first feature traveling north into the Gulf today appears best
captured by the NAM/GFS models. The next big storm moving across
the Bering Sea today through Thursday is also best captured by the
NAM/GFS, bringing strong winds and higher seas to much of the
Bering and Aleutians.

&&

.AVIATION...
VFR conditions will continue through today, but will likely drop
under 5000 ft this evening as rain begins to fall over the
Anchorage bowl.

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Rain will quickly spread westward back into Southcentral early
this evening as the Gulf low slowly moves into Prince William
Sound and dissipates. This low will be strong enough to cause a
brief increase in the gap winds throughout Prince William Sound as
it passes through, all of which should then diminish by late
tonight. Rain will then continue in most areas into Wednesday,
giving little if any break in the weather before a gale force
front moves through the Gulf late Wednesday-Thursday. It is with
this feature that most of the forecast updates were made today,
mostly with increasing winds throughout the Gulf and gusty gap
winds from Turnagain Arm eastward into the Copper River area.
While a weak lee side low is expected to develop behind this
front, a strong pressure gradient created from a much deeper low
over the west coast will be the primary driver for gusty winds
that are expected to develop over the Anchorage Bowl and Matanuska
Valley on Thursday. There will be some downsloping associated
with these winds, however with winds quickly becoming
southwesterly aloft this will likely not be strong enough to
prevent rain from falling over the downslope prone areas on the
lee side of the Chugach for most of the day Thursday. Conditions
throughout the area will begin to slowly improve on Friday, but
with continued cyclonic flow aloft most areas will remain cloudy
and showery to end the work week.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
There is an upper level trough over the Kuskokwim Delta so expect
light showers to continue overnight as this feature pushes inland.
After a short break between storms, the main event is expected to
begin tomorrow as a low pressure system rapidly intensifies over
the Bering Sea. The leading edge of the precipitation shield will
reach western Alaska tomorrow afternoon with the bulk of the QPF
expect late Wednesday night and into Thursday morning. The tight
pressure gradient will hold up through Thursday and widespread
gusty winds are anticipated. A long fetch of strong westerly winds
will also lead to increased surge and the potential of minor
coastal flooding and beach erosion. Right now, the highest
potential for flooding looks to be for locations along Kuskokwim
Bay, including Quinhagak and Goodnews Bay, where water levels
could be 2-3 feet above high astronomical tide on Thursday. See
the Special Weather Statement for more information.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A strong jet parallels the Aleutian Chain this forecast period.
Expect rough seas, strong winds and rapid cyclogenesis. This is a
high confidence event, with multiple solutions progging a minimum
central pressure of around 960 mb by Wednesday night. The low
will trek across the Central Bering on Wednesday and Thursday.

&&

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

The extended forecast period begins Thursday night with the
remnants of a powerful Bering sea storm moving eastward into
Southern Alaska. This strong cyclone will still be impacting
Bristol Bay and the Alaska Peninsula with strong gale force winds
with the strongest core of winds moving into the Gulf of Alaska
Friday. Strong mid level westerly flow will be supporting a well
defined upslope/downslope pattern with most lower elevations areas
drying out while precipitation favors higher mountain slopes.
This pattern regime will persist through Saturday before the
pressure gradient weakens and a trough digs out over the Bering
Sea. Much uncertainty develops at this juncture as the global
models diverge rapidly with the development of a surface low along
the subtropical warm front. The Canadian GDPS and GFS prefer to
phase the upper trough with the entire warm front, creating a much
deeper and slower moving low while the ECMWF has a faster moving
low and a lower amplitude trough. The differences become stark by
Sunday as the ECMWF is racing the low across northern Gulf of
Alaska while the Canadian and GFS depict a deep low south of the
Eastern Aleutians. Long story short, we continue to favor a WPC
blend approach which favors more stable ensemble solutions showing
a weaker low moving north toward the AK Peninsula Sunday and
Monday with increasing chances for precipitation into the early
week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 119 130-132 139 155-170 172-178 185.
		 Storm 179 180 181.

&&

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