Small Craft Advisory 18, NWS Juneau, AK

428 
FZAK52 PAJK 090013
CWFAEG

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
313 PM AKST Fri Jan 8 2021

Southeast Alaska Coastal Waters from Dixon Entrance to
Cape Suckling out 100 NM

Wind forecasts reflect the predominant speed and direction
expected. Seas forecasts represent the average of the highest
one-third of the combined windwave and swell height.

PKZ099-091815-
313 PM AKST Fri Jan 8 2021
.SYNOPSIS FOR OUTSIDE WATERS...
A weakening low moves northward through the central Panhandle and
into Canada by tonight. A storm force front will move northward 
into the Eastern Gulf on Saturday. 

$$

PKZ041-091815-
Dixon Entrance to Cape Decision-
313 PM AKST Fri Jan 8 2021

...STORM WARNING SATURDAY...

.TONIGHT...SW wind 30 kt becoming S 20 kt in the evening, then
becoming SE 35 kt late. Seas 17 ft. 
.SAT...SE wind 55 kt. Seas 26 ft. Rain.
.SAT NIGHT...S gale to 45 kt. Seas 30 ft. Rain.
.SUN...S gale to 40 kt. Seas 27 ft. Rain.
.SUN NIGHT...S gale to 35 kt. Seas 22 ft. Rain.
.MON...S wind 25 kt. Seas 22 ft. 
.TUE...S wind 25 kt. Seas 20 ft. 
.WED...SW wind 20 kt. Seas 16 ft. 

$$

PKZ042-091815-
Cape Decision to Cape Edgecumbe-
313 PM AKST Fri Jan 8 2021

...STORM WARNING SATURDAY...

.TONIGHT...SW wind 20 kt becoming SE 35 kt late. Seas 17 ft. 
.SAT...SE wind 50 kt. Seas 25 ft. Rain.
.SAT NIGHT...SE storm force wind to 50 kt. Seas 30 ft. Rain.
.SUN...S gale to 40 kt. Seas 26 ft. Rain.
.SUN NIGHT...SE wind 30 kt. Seas 21 ft. Rain.
.MON...S wind 25 kt. Seas 21 ft. 
.TUE...S wind 25 kt. Seas 20 ft. 
.WED...S wind 20 kt. Seas 14 ft. 

$$

PKZ043-091815-
Cape Edgecumbe to Cape Fairweather-
313 PM AKST Fri Jan 8 2021

...STORM WARNING SATURDAY...

.TONIGHT...SW wind 15 kt becoming SE 25 kt late. Seas 15 ft. 
.SAT...E wind 50 kt. Seas 19 ft building to 26 ft in the 
afternoon. Rain.
.SAT NIGHT...E gale to 45 kt. Seas 29 ft. Rain.
.SUN...SE gale to 40 kt. Seas 25 ft. Rain.
.SUN NIGHT...SE wind 25 kt. Seas 20 ft. S swell. Rain showers
and slight chance of thunderstorms. 
.MON...S wind 25 kt. Seas 20 ft. 
.TUE...S wind 25 kt. Seas 18 ft. 
.WED...S wind 20 kt. Seas 13 ft. 

$$

PKZ051-091815-
Cape Fairweather to Icy Cape-
313 PM AKST Fri Jan 8 2021

...STORM WARNING SATURDAY...

.TONIGHT...S wind 20 kt. Seas 14 ft. 
.SAT...E wind 35 kt increasing to 50 kt in the afternoon. Seas 16
ft building to 23 ft in the afternoon. Rain in the afternoon. 
.SAT NIGHT...E gale to 45 kt. Seas 28 ft. Rain.
.SUN...SE gale to 40 kt. Seas 25 ft. Rain.
.SUN NIGHT...SE wind 30 kt. Seas 20 ft. Rain showers and
slight chance of thunderstorms. 
.MON...SE wind 25 kt. Seas 19 ft. 
.TUE...S wind 25 kt. Seas 17 ft. 
.WED...S wind 20 kt. Seas 12 ft. 

$$

PKZ052-091815-
Icy Cape to Cape Suckling-
313 PM AKST Fri Jan 8 2021

...STORM WARNING SATURDAY...

.TONIGHT...S wind 20 kt. Seas 14 ft. 
.SAT...E wind 35 kt increasing to 50 kt in the afternoon.
Seas 15 ft building to 23 ft in the afternoon. Rain in the
afternoon. 
.SAT NIGHT...E gale to 45 kt. Seas 28 ft. Rain.
.SUN...SE gale to 40 kt. Seas 26 ft. Rain.
.SUN NIGHT...SE gale to 35 kt. Seas 22 ft. Rain showers and
slight chance of thunderstorms. 
.MON...SE wind 25 kt. Seas 18 ft. 
.TUE...SE wind 20 kt. Seas 15 ft. 
.WED...SE wind 15 kt. Seas 11 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
247 PM AKST Thu Jan 7 2021

.SHORT TERM.../Through Sat night/ Short range forecast is very
active with a new system impacting the panhandle every day.
Today's system ended up being a little stronger then anticipated
with a narrow band of strong winds just ahead of the front as it
moved through this morning. Gale force winds were observed in
Stephens Passage, and Cross Sound, and gusty winds were seen at
Petersburg, Angoon, Sitka, Yakutat, Ketchikan, and Gustavus.
There was even a ship report received just off Lituya Bay around
11 am of 55 kt with gusts to 70 kt likely due to a tip jet off of
Cape Spencer producing locally higher winds in that vicinity.
There has also been some thunderstorm activity along and behind
the front today. It has mostly been detected by lightning
detection, but reports of thunder from spotters and airport
observers around Baranof island have come in as well.

Into tonight and tomorrow, the remains of that front and the low
coming up behind it for Fri are the main issues. Winter weather
advisory remain up for the Haines and Klondike Highways until
midnight, but are mainly for the higher elevations of the roads.
The towns are just too warm right now to get any major
accumulations. Attention then turns to the low coming up from the
south. Guidance has been terrible with low timing and position
with solutions all over the eastern gulf. 12z model runs were
divided into two camps with GFS and Nam faster and farther north,
while the Canadian and ECMWF were slower and farther south. Since
then the low has developed enough that satellite imagery
comparisons with model initialization is showing that the Canadian
and ECMWF had the better representation and the new 18z runs of
the Nam and GFS have trended farther south. Current forecast more
closely follows the Canadian and ECMWF solution at this time. What
is still up in the air is the wind forecast. This low looks like
it will be small, with a narrow band of strong (possibly high)
winds wrapped around it. There is high uncertainly where, or if,
these winds will hit the southern panhandle tomorrow morning
(could be as far east as Ketchikan and Metlakatla, or it could
stay just off the outer coast). Gusts to 40 to 50 mph looks to be
a good bet, but there is an outside chance of an area of 60+ mph
gusts showing up somewhere in the southern panhandle. We will be
keeping an eye on this system as it develops and moves into the
area tonight. In any case that low rapidly weakens as it moves up
the panhandle on Fri spreading more rain and more gusty winds as
it comes.

Sat brings yet another front that has the potential to be
stronger then today's system. Storm force winds are expected out
in the gulf and gusty winds for the southern half and outer coast
of the panhandle from this front by Sat afternoon. Another round
of mostly rain is expected as well, with snow possible for the
northern inner channels again especially Sat night. Higher
confidence on this system with models generally agreeing on
overall timing and strength of the system.

.LONG TERM...A very active winter-time pattern continues well
into the mid-range. High confidence exists for a developing storm
that eventually evolves out of a wave currently crossing the
North Pacific along 40 N near the International Dateline. By both
the GFS and NAM solutions, the storm deepens into yet another
storm force low of 50 to 60 kt winds in the southeast gulf. ECMWF
and Canadian solutions still keep it at strong gales, so we
currently split the difference with widespread 45 to 50 kt
southeasterlies late Saturday. Ketchikan, Metlakatla, Prince of
Wales Island, and Sitka should all pay heed to this weekend's
forecast for at least the potential for a period of damaging wind
gusts. However, we cannot be certain at this juncture. Other
portions of the Panhandle could feel effects of the front later
Saturday night in the form of stronger winds. But this of course,
depends on the ultimate strength of the system. We also feel
confident in widespread southerlies of 25 kt, potentially gale
force through north-south inner channels, and 25 kt easterlies
through east-west channels. Farther north in Lynn Canal, predicted
parallel pressure gradient will lead to precarious wind forecasts
of low confidence in this region. Winds could be south or north,
but we kept magnitudes lower than the south and central Inner
Channels.

Saturday's gulf storm also should spread precipitation in the form
of rain across Southeast. As the precipitation shield presses
northward Saturday night, we anticipate that cold air across the
Chilkat River Valley and the higher elevations of the South
Klondike will translate to moderate to heavy snow, especially
leading into Sunday. From Juneau south, confidence in liquid
precipitation is high. Sure, we could have chances of occasional
slush north of Juneau out the road, or deep in the Mendenhall
Valley, but the overwhelming story will be rain with temperatures
in the temperatures in the mid 30s to low 40s.

A more pronounced slug of moisture follows for late Sunday which
should add to the Panhandle's winter blues. Again, confidence in
rain is high through the Panhandle from Juneau south and along the
coast. But confidence falls north into Upper Lynn Canal where
difficult wind and temperature forecasts prove pivotal on ultimate
impacts: big snow or big rain.

The parade of storms appears to have no end next week. There will
be breaks of course, but storm after storm keeps rain in the
forecast, and likely some snow issues in the far north. Haines
and South Klondike snow cannot be ruled out on occasion.
Wind will also be a threat, but it is far too early to say when
and where.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind from 6 PM this evening to midnight AKST tonight for
     AKZ027.
     Strong Wind through late tonight for AKZ023.
     Winter Weather Advisory until midnight AKST tonight for AKZ018-
     019.
     Strong Wind until midnight AKST tonight for AKZ017.
MARINE...Gale Warning for PKZ022-041>043-051-052.
     Small Craft Advisory for PKZ021-031>036-053.

&&

EAL/JWA

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