Gale Warning 77, NWS Juneau, AK

229 
FZAK51 PAJK 241954
CWFAJK

Coastal Waters Forecast FOR Southeast Alaska...UPDATED
National Weather Service Juneau AK
1054 AM AKST Sat Feb 24 2018

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

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

PKZ098-250345-
1054 AM AKST Sat Feb 24 2018
.SYNOPSIS FOR SOUTHEAST ALASKA INNER CHANNELS COASTAL WATERS...
 A storm force low will move E through the northern Gulf 
Saturday. This low will then track SE across the southern 
panhandle Saturday night, reaching western British Columbia by 
mid- Sunday morning. 

$$

PKZ011-250345-
Glacier Bay-
1054 AM AKST Sat Feb 24 2018

.TODAY...SE wind 10 kt becoming NE 15 kt in the afternoon. Seas 3
ft. Snow.
.TONIGHT...N wind 20 kt. Gusts to 35 kt. Seas 4 ft. Freezing
spray late. 
.SUN...NW wind 10 kt. Seas 2 ft or less. 
.SUN NIGHT...N wind 15 kt. Seas 3 ft. 
.MON...S wind 15 kt. Seas 3 ft. 
.TUE...S wind 10 kt becoming N. Seas 2 ft or less. 
.WED...N wind 15 kt. Seas 3 ft. 



$$

PKZ012-250345-
Northern Lynn Canal-
1054 AM AKST Sat Feb 24 2018

...GALE WARNING LATE TONIGHT...

.TODAY...N wind 15 kt becoming S. Seas 3 ft. Snow.
.TONIGHT...N wind 25 kt increasing to 35 kt late. Seas 6 ft.
Freezing spray late. 
.SUN...N wind 30 kt diminishing to 20 kt in the afternoon.
Seas 5 ft. Freezing spray in the morning. 
.SUN NIGHT...N wind 15 kt. Seas 3 ft. 
.MON...S wind 20 kt. Seas 4 ft. 
.TUE...N wind 10 kt. Seas 3 ft. 
.WED...N wind 25 kt. Seas 5 ft. 



$$

PKZ013-250345-
Southern Lynn Canal-
1054 AM AKST Sat Feb 24 2018

...SMALL CRAFT ADVISORY LATE TONIGHT...

.TODAY...N wind 15 kt becoming S 20 kt. Gusts to 35 kt. Seas 4 
ft. Snow.
.TONIGHT...N wind 20 kt increasing to 30 kt late. Seas 5 ft. 
.SUN...N wind 25 kt. Seas 5 ft. 
.SUN NIGHT...N wind 15 kt. Seas 3 ft. Snow.
.MON...S wind 15 kt. Seas 4 ft. 
.TUE...S wind 10 kt becoming N. Seas 2 ft or less. 
.WED...N wind 20 kt. Seas 4 ft. 



$$

PKZ021-250345-
Icy Strait-
1054 AM AKST Sat Feb 24 2018

...SMALL CRAFT ADVISORY THIS AFTERNOON AND EVENING...

.TODAY...E wind 10 kt increasing to 25 kt. Seas 2 ft or less
building to 5 ft. Snow.
.TONIGHT...E wind 25 kt. Seas 5 ft. 
.SUN...NE wind 10 kt. Seas 3 ft. 
.SUN NIGHT...E wind 20 kt. Seas 4 ft. 
.MON...SE wind 20 kt becoming SW. Seas 4 ft. 
.TUE...W wind 10 kt. Seas 3 ft. 
.WED...E wind 15 kt. Seas 3 ft. 



$$

PKZ022-250345-
Cross Sound-
1054 AM AKST Sat Feb 24 2018

...SMALL CRAFT ADVISORY THROUGH THROUGH LATE TONIGHT...

.TODAY...E wind increasing to 25 kt. Seas 10 ft. S swell. Snow. 
Rain in the afternoon. 
.TONIGHT...NE wind 30 kt becoming N 10 kt late. Seas 13 ft. 
.SUN...E wind 15 kt. Seas 13 ft. S swell. 
.SUN NIGHT...E wind 15 kt. Seas 10 ft. S swell. Snow.
.MON...W wind 25 kt. Seas 14 ft. 
.TUE...W wind 15 kt. Seas 15 ft. 
.WED...E wind 30 kt. Seas 12 ft. 



$$

PKZ031-250345-
Stephens Passage-
1054 AM AKST Sat Feb 24 2018

UPDATED

...SMALL CRAFT ADVISORY THROUGH THIS AFTERNOON...

.REST OF TODAY...SE wind 30 kt. Gusts to 45 kt, except 35 kt out
of interior passes. Seas 6 ft. Snow.
.TONIGHT...S wind 20 kt becoming N late. Seas 4 ft. Snow showers
in the evening. 
.SUN...NW wind 15 kt. Seas 3 ft. 
.SUN NIGHT...NW wind 20 kt. Seas 4 ft. 
.MON...S wind 25 kt. Seas 5 ft. 
.TUE...S wind 15 kt. Seas 3 ft. 
.WED...N wind 20 kt. Seas 4 ft. 



$$

PKZ032-250345-
Northern Chatham Strait-
1054 AM AKST Sat Feb 24 2018

UPDATED

...SMALL CRAFT ADVISORY THROUGH LATE TONIGHT...

.REST OF TODAY...S wind 30 kt. Seas 6 ft. Snow and rain showers. 
.TONIGHT...SE wind 20 kt becoming N late. Seas 5 ft. Snow showers
in the evening. 
.SUN...N wind 20 kt. Seas 4 ft. 
.SUN NIGHT...N wind 20 kt. Seas 4 ft. Snow.
.MON...S wind 20 kt. Seas 4 ft. 
.TUE...S wind 15 kt. Seas 3 ft. 
.WED...N wind 20 kt. Seas 4 ft. 



$$

PKZ033-250345-
Southern Chatham Strait-
1054 AM AKST Sat Feb 24 2018

UPDATED

...SMALL CRAFT ADVISORY THROUGH LATE TONIGHT...

.REST OF TODAY...S wind 30 kt. Seas 6 ft, except 12 ft near ocean
entrances. Snow and rain. 
.TONIGHT...SW wind 30 kt becoming N 30 kt late. Seas 7 ft, except
18 ft near ocean entrances. Snow showers and rain showers in the 
evening. 
.SUN...N wind 15 kt. Seas 3 ft, except 14 ft near ocean
entrances. 
.SUN NIGHT...N wind 15 kt. Seas 3 ft, except 11 ft near ocean
entrances. Snow.
.MON...SW wind 20 kt. Seas 5 ft. 
.TUE...S wind 15 kt. Seas 3 ft. 
.WED...NE wind 15 kt. Seas 3 ft. 



$$

PKZ034-250345-
Frederick Sound-
1054 AM AKST Sat Feb 24 2018

UPDATED

...SMALL CRAFT ADVISORY THROUGH THIS AFTERNOON...

.REST OF TODAY...SE wind 30 kt. Gusts to 45 kt, except 35 kt out
of interior passes. Seas 6 ft. Snow and rain. 
.TONIGHT...SE wind 25 kt becoming NW late. Seas 5 ft. Snow
showers and rain showers in the evening. 
.SUN...NW wind 10 kt. Seas 2 ft or less. 
.SUN NIGHT...N wind 20 kt. Seas 4 ft. 
.MON...S wind 25 kt. Seas 5 ft. 
.TUE...S wind 15 kt. Seas 3 ft. 
.WED...NE wind 15 kt. Seas 4 ft. 



$$

PKZ035-250345-
Sumner Strait-
1054 AM AKST Sat Feb 24 2018

UPDATED

...SMALL CRAFT ADVISORY THROUGH LATE TONIGHT...

.REST OF TODAY...S wind 25 kt. Gusts to 40 kt. Seas 5 ft. Rain
and snow. 
.TONIGHT...SW wind 25 kt becoming SE late. Seas 6 ft, except
10 ft near ocean entrances. Rain and snow showers in the evening.
.SUN...NW wind 15 kt in the morning becoming light. Seas 3 ft
in the morning then 2 ft or less. Near ocean entrances, seas
7 ft. 
.SUN NIGHT...N wind 10 kt. Seas 2 ft or less, except 6 ft near
ocean entrances. 
.MON...SE wind 20 kt becoming SW. Seas 4 ft. 
.TUE...W wind 10 kt. Seas 3 ft. 
.WED...E wind 10 kt. Seas 2 ft or less. 



$$

PKZ036-250345-
Clarence Strait-
1054 AM AKST Sat Feb 24 2018

...SMALL CRAFT ADVISORY THIS AFTERNOON THROUGH LATE TONIGHT...

.TODAY...NW wind 10 kt becoming SE 25 kt. Seas 2 ft or less
building to 5 ft. Near ocean entrances, seas 7 ft. Snow in the
morning. Rain in the afternoon. 
.TONIGHT...S wind 25 kt. Seas 6 ft, except 9 ft near ocean
entrances. Rain and snow showers. 
.SUN...NW wind 15 kt. Seas 3 ft, except 8 ft near ocean
entrances. 
.SUN NIGHT...NW wind 15 kt. Seas 2 ft or less, except 5 ft
near ocean entrances. 
.MON...S wind 25 kt. Seas 5 ft. 
.TUE...SW wind 20 kt. Seas 5 ft. 
.WED...E wind 15 kt. Seas 3 ft. 



$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
251 PM AKST Fri Feb 23 2018

.SHORT TERM.../Through Saturday night/ A weakening low will move
SE out of the southern panhandle tonight. High pressure will build
over the Yukon tonight, then shift E Sat. A developing low will
move E into the NW gulf late tonight, then move across the
northern gulf Sat. The low should turn SE and move into the
southern panhandle Sat night. The associated occluded front will
move to the eastern gulf by early Sat morning, then swing across
SE AK Sat afternoon and evening. Generally preferred the 12z
GFS/Canadian handling of the second low, with the 12z NAM just a
little further N with the track. The 18z NAM shifted the low track
slightly southward and is very close to preferred consensus.

Main forecast concerns will be precip potential/ptype/amounts and
winds. Rain and snow showers with the low currently over the
southern area will move out tonight. Not expecting much in the way
of snowfall from these showers as low level temps will be above
freezing during most of this precip. Precip associated with the
second low and occluded front will move rapidly E across the gulf
and reach the outer coast of SE AK by around 15z Sat. This precip
should reach the far eastern inner channels by 20z Sat. Some
colder air will be in place ahead of the system, which will cause
precip to begin as snow pretty much all areas. Think the
central/southern coast and southern inner channels will transition
to rain or a mix, except for the far eastern parts, which should
remain mainly snow. Think the highest precip amounts will occur
from the central coast SE to the southern inner channels. The NE
part of this heavier precip band will likely remain mostly snow,
and have issued a winter weather advisory for zones 21,22, and 24
from 15z Sat to 01z Sun, and zone 26 from 18z Sat to 03z Sun.
Expect 3-5 inches in the advisory areas. Zones 20 and 25 could
get close to advy levels but some easterly flow will tend to limit
the snowfall a bit. Went for 2-4 inches for those areas Sat.
Lighter snowfall is expected over the far N. Hyder area will
likely see 3-5 inches of snow with the main frontal band Sat
afternoon and evening, but this is below advy levels. Elsewhere
along the coast and southern areas, 1 to 3 inches of snow will be
possible before it mixes with or changes to rain.

Precip should transition to showers Sat evening after occluded
front moves in. Most enhanced showers will be over the southern
half of the area along and S of the low track. The low itself will
have some mild air with it so most of the showers will likely be
rain along the southern coast. Precip over the N will diminish as
low moves inland Sat night.

Will have strong northerly winds over the northern inner channels
tonight between first low moving out and high pressure building
over the Yukon. Looking like gales for Lynn Canal with SCA level
winds possible over the central areas. These winds will decrease
rapidly late tonight and Sat morning as northerly gradient
weakens. Gale force W-NW winds will be over much of the S half of
the gulf to start tonight, then drop off gradually as flow backs
around to a more southerly direction late tonight ahead of
approaching occluded front, but after the front moves through, a
band of gale to storm force W-NW winds will move into the southern
half of the gulf Sat. Could be a small area of storm force winds
on S side of the low moving through the area as second wrap of
occluded front forms Sat. With the long fetch gale to storm force
winds over the central and southern gulf, seas will be very high,
with 20+ ft seas expected during much of the time through Sat
night.

Otherwise, some patchy fog will develop over parts of the central
and southern areas as clouds break and winds drop off this evening.
Think this fog will dissipate late tonight though as clouds
increase again ahead of the occluded front.

.LONG TERM.../Sunday through Friday/ We'll start off the long
term on Sunday with a broad upper level trough positioned over the
panhandle and western Canada and an upper level ridge building
over the western gulf. A weakening surface low associated with a
shortwave embedded within the upper level trough will continue to
traverse southeast across the panhandle, taking with it lingering
precipitation. This feature will also help to tighten the pressure
gradient between it and a weak high pressure near the border with
mainland Alaska and the Yukon. This setup may provide a brief
northerly outflow event, so we increased winds accordingly through
Lynn Canal. As the ridge of high pressure strengthens over the
gulf and pushes east Sunday night into early Monday morning, this
should help to fully clear out precipitation, albeit briefly,
before our next system moves in Monday.

Continuing with our progressive pattern trend, a shortwave with
an associated developing surface low will dig into the western
gulf Sunday night. A weather front with the low will lift across
the eastern gulf and impact the panhandle Monday continuing into
Tuesday. 700 mb model frontogenesis shows strengthening along the
front, which should help trigger the lift we need for
precipitation. Models also show significant moisture advection
ahead of the front on Monday, so we could see some substantial
precip amounts with this system. This may potentially be a tricky
system regarding precip type; model 925 mb temps show a relatively
cold air mass over the panhandle, so precip could start off as
snow and briefly transition to a rain/snow mix or remain all snow.

We mainly focused on forecast updates for the early period in the
long term, which included the Sunday through Monday timeframe. We
chose a NAM/GEM blend, using NAM more for winds and GEM for
precip elements. After this timeframe, we allowed WPC guidance to
remain and added in NBM for select elements, mainly temperatures,
which were adjusted down for later next week.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Winter Weather Advisory from 9 AM to 6 PM AKST Saturday for
     AKZ026.
     Winter Weather Advisory from 6 AM to 4 PM AKST Saturday for
     AKZ021-022-024.
MARINE...Gale Warning for PKZ012-041>043-051-052.
     Small Craft Advisory for PKZ013-021-022-031>036.
     Small Craft Advisory due to Seas for PKZ053.

&&

RWT/Voveris

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