Small Craft Advisory 477, NWS Juneau, AK

327 
FZAK52 PAJK 171046
CWFAEG

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
246 AM AKDT Sun Oct 17 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.

PKZ099-180500-
246 AM AKDT Sun Oct 17 2021
.SYNOPSIS FOR OUTSIDE WATERS...
A weak surface ridge over the eastern Gulf will shift southeast
through Sunday. A high end gale force front over the central
Gulf on Sunday afternoon will stall over the far eastern Gulf by
Monday afternoon and begin weakening Tuesday afternoon.   

$$

PKZ041-180500-
Dixon Entrance to Cape Decision-
246 AM AKDT Sun Oct 17 2021

...GALE WARNING LATE TONIGHT...

.TODAY...N wind 10 kt early in the morning becoming light, then
becoming SE 15 kt in the afternoon. Seas 8 ft. 
.TONIGHT...SE wind 20 kt increasing to 35 kt late. Seas 10 ft 
building to 16 ft late. 
.MON...SE gale to 40 kt. Seas 24 ft. 
.MON NIGHT...SE gale to 45 kt. Seas 29 ft. 
.TUE...SE gale to 45 kt. Seas 26 ft. 
.WED...SE wind 30 kt diminishing to 15 kt. Seas 19 ft
subsiding to 11 ft. 
.THU...E wind 30 kt. Seas 17 ft. 

$$

PKZ042-180500-
Cape Decision to Cape Edgecumbe-
246 AM AKDT Sun Oct 17 2021

...GALE WARNING LATE TONIGHT...

.TODAY...N wind 10 kt becoming SE 20 kt in the afternoon. Seas 7 
ft. W swell early in the morning. 
.TONIGHT...SE wind 25 kt increasing to 40 kt late. Seas 10 ft 
building to 20 ft late. 
.MON...SE gale to 45 kt. Seas 27 ft. Rain in the afternoon. 
.MON NIGHT...SE gale to 45 kt. Seas 31 ft. Rain.
.TUE...SE gale to 45 kt. Seas 27 ft. 
.WED...SE gale to 35 kt diminishing to 15 kt. Seas 20 ft
subsiding to 12 ft. 
.THU...E wind 30 kt. Seas 18 ft. 

$$

PKZ043-180500-
Cape Edgecumbe to Cape Fairweather-
246 AM AKDT Sun Oct 17 2021

...GALE WARNING THIS EVENING THROUGH TONIGHT...

.TODAY...NW wind 10 kt becoming SE 15 kt in the morning, then
increasing to 25 kt in the afternoon. Seas 7 ft. 
.TONIGHT...SE wind increasing to 35 kt in the evening. Seas 13 ft
building to 23 ft late.
.MON...SE gale to 45 kt. Seas 29 ft. Rain in the afternoon. 
.MON NIGHT...E gale to 45 kt. Seas 32 ft. Rain.
.TUE...SE gale to 40 kt. Seas 28 ft. 
.WED...SE gale to 35 kt diminishing to 20 kt. Seas 20 ft
subsiding to 13 ft. 
.THU...E wind 15 kt increasing to 25 kt. Seas 17 ft. 

$$

PKZ051-180500-
Cape Fairweather to Icy Cape-
246 AM AKDT Sun Oct 17 2021

...GALE WARNING THIS EVENING THROUGH TONIGHT...

.TODAY...SW wind 10 kt becoming SE 25 kt in the afternoon. Seas 7
ft.
.TONIGHT...SE wind 30 kt becoming E 45 kt late. Seas 14 ft 
building to 26 ft late. 
.MON...E gale to 40 kt. Seas 29 ft. 
.MON NIGHT...E gale to 45 kt. Seas 32 ft. 
.TUE...SE gale to 40 kt. Seas 29 ft. 
.WED...E wind 30 kt becoming SE 20 kt. Seas 20 ft subsiding
to 13 ft. 
.THU...E wind 15 kt. Seas 15 ft. 

$$

PKZ052-180500-
Icy Cape to Cape Suckling-
246 AM AKDT Sun Oct 17 2021

...GALE WARNING THIS AFTERNOON THROUGH TONIGHT...

.TODAY...S wind 20 kt becoming E 35 kt. Seas 6 ft building to 12 
ft in the afternoon. 
.TONIGHT...E wind increasing to 40 kt in the evening. Seas building
to 27 ft late. Rain late. 
.MON...E gale to 45 kt. Seas 29 ft. Rain.
.MON NIGHT...E gale to 45 kt. Seas 32 ft. Rain.
.TUE...E gale to 45 kt becoming SE 30 kt late. Seas 30 ft. 
.WED...SE wind 30 kt diminishing to 15 kt late. Seas 19 ft 
subsiding to 13 ft. 
.THU...E wind 15 kt. Seas 13 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
223 PM AKDT Sat Oct 16 2021

.SHORT TERM.../ Through Monday night/...The short term forecast
begins with a 500 mb trough and associated surface low moving
eastward. Some showers are possible around southern POW Island and
the Ketchikan/Metlakatla area. As the area of low pressure moves
eastward, these showers will become fewer in number and eventually
fade out. Elsewhere around the Panhandle, skies will be clear and
quite. Have kept fog in the forecast for some areas of the
panhandle due to fog forming last night, the abundance of clear
skies, and low tide will happen overnight again. Temperatures
tonight will cool to the 20s to near 30 in areas that will have
clear skies, slightly warmer 30s will be found the in south where
cloud cover will keep temperatures slightly warmer. If clouds
clear out faster than expected, temperatures could dip cooler than
expected.

Sunday will have a ridge build and pass over SE AK so Sunday is
looking like a nice day overall with most of the panhandle seeing
mostly sunny to sunny skies. That being said, clouds will slowly
increase from west to east as the next weather system and
associated front moves into the gulf. Sunday’s afternoon highs
will reach the 40s around the area.

Turning the page on the weekend and going into the next week will
bring back the active weather pattern. An area of low pressure is
expected to move into the gulf Sunday night, then sit and spin
over the gulf through Monday. This ‘sit and spin’ pattern will
slow the front’s easterly advance into the Panhandle. So rain
chances over land areas don’t really start going up until
Tuesday afternoon or later.

This slow progression inland would mean Monday will play out dry
but cloudy. Monday morning temps look to be in the 30s, thanks to
overnight cloud cover, and afternoon temps look to be in the 40s,
some near 50 degree highs are possible in the southern half of the
panhandle.

On a more specific side-note - there is evidence of breezy winds
in downtown Juneau and around Douglas Island Monday into Monday
night. It looks like a synoptically driven mountain wave, nothing
too extreme but breezy winds with stronger wind gusts have been
included in the forecast.

.LONG TERM.../Monday through Saturday as of 10PM Friday/...The
front that we have been referring to for a few days will be
located over the eastern Gulf for Monday, the beginning of the
long-term forecast period, and linger just offshore over the
eastern Gulf into the middle of next week. We have updated the
winds to storm-force along the front poised over the eastern Gulf,
just off the outer coast. Peak winds look to occur Monday
evening. Winds over the Inner Channel waters look to get up to
borderline low-end Gale near ocean entrances and to around 15 to
25 knots elsewhere over the inner channels.

The aforementioned early-week storm-force frontal system has an
impressively long fetch of deep moisture originating from around
the tropical Pacific. Model forecast PW, IVT values well over
1,000 kg/(ms), and 700mb RH values indicate that this is a rather
potent atmospheric river. Luckily, the majority of the
precipitation looks to be aimed offshore over the open Gulf waters
with this system as it lingers off the coast.

If this system ends up taking a jog in its track 100 to 200 miles
to the east and linger over the Panhandle, it will be a rather
impactful system with regard to rainfall accumulation and wind
over southeast Alaska.

Another low looks to approach the eastern Gulf from the south for
late week into the weekend. There is considerable deterministic
model and ensemble member spread this evening with the track of
this system and any system after that. Therefore, we phased to WPC
for day 7(Thursday), onward, for the winds. Currently, it looks
like it may be a Gale force low that moves northward, just off
the coast, and progressively weakens as it moves northward and
makes landfall somewhere between Anchorage and Yakutat.

As for temperatures, highs warm into the middle 40s to middle 50s
throughout the Panhandle with the highest temperatures occurring
in the southern Panhandle for the duration of the long-term
forecast period. Overnight low temperatures gradually warm to
values primarily between the lower 30s to upper 40s for the period
with the warmest temperatures being toward the south toward the
latter half of the week. This is indicated via MOS guidance, 850mb
model forecast warm temperature advection moving toward the area,
and model forecast 1,000 to 850mb thickness values over the area
for the timeframe. This occurs with the southerly push out ahead
of the aforementioned weather systems as they approach the
forecast area.

Forecast confidence is above average for the first half and below
average for the 2nd half of the long-term forecast period, due to
variations in model agreement. A GFS/NAM/ECMWF/CMC solution was
used for the gridded forecast, tonight.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale Warning for PKZ052-310.
     Small Craft Advisory for PKZ041>043-051.

&&

GJS/JLC

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