Storm Warning 32, NWS Juneau, AK

273 
FZAK67 PAJK 211308
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
408 AM AKST Sat Nov 21 2020

Offshore waters forecast for Gulf of Alaska east of 144W

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.

PKZ398-220715-
408 AM AKST Sat Nov 21 2020
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A storm force front will move across the gulf and over the inner 
channels through Saturday. A second storm force low will move 
across the gulf and inner channels early next week. 

$$

PKZ310-220715-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
408 AM AKST Sat Nov 21 2020

...STORM WARNING EARLY TODAY...

.TODAY...SE wind 50 kt becoming SW 25 kt in the morning. Seas 17 
ft. SW swell in the afternoon. Rain early in the morning. 
.TONIGHT...SW wind 15 kt in the evening becoming variable less
than 15 kt. Seas 13 ft. W swell. 
.SUN...Wind variable less than 15 kt. Seas 11 ft. W swell. 
.SUN NIGHT...SE wind 30 kt increasing to gale to 40 kt late.
Seas 11 ft building to 14 ft late. Rain late. 
.MON...SW gale to 45 kt. Seas 23 ft. 
.TUE...NW wind 30 kt. Seas 22 ft. 
.WED...S wind 30 kt. Seas 13 ft. 

$$

815 
FZAK67 PAJK 220202
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
502 PM AKST Sat Nov 21 2020

Offshore waters forecast for Gulf of Alaska east of 144W

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.

PKZ398-222015-
502 PM AKST Sat Nov 21 2020
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A weakening low dissipates south of Kodiak Island through
Saturday night. A new low west of Prince of Wales Island develops
and moves through the southern panhandle Sunday. A storm force 
low moves into the gulf on Monday. 

$$

PKZ310-222015-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
502 PM AKST Sat Nov 21 2020

.TONIGHT...SW wind 20 kt in the evening becoming variable less
than 15 kt. Seas 15 ft. W swell. 
.SUN...Wind variable less than 15 kt. Seas 11 ft. W swell. 
.SUN NIGHT...SE wind 25 kt increasing to gale to 40 kt late.
Seas 10 ft building to 13 ft late. Rain late. 
.MON...SE gale to 45 kt becoming SW gale to 40 kt in the
afternoon. Seas 18 ft building to 23 ft in the afternoon. Rain.
.MON NIGHT...SW gale to 40 kt becoming N gale to 35 kt late.
Seas 31 ft. Rain.
.TUE...NW wind 30 kt. Seas 22 ft. 
.WED...S wind 30 kt. Seas 13 ft. 
.THU...SW wind 20 kt. Seas 14 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
258 PM AKST Fri Nov 20 2020

.SHORT TERM...Incoming system for Saturday has all eyes in SE AK
watching it. The front will approach the SE AK panhandle pushing
out the few lingering showers over the panhandle this evening with
minor accumulations of rain or snow amounts. The weather front
will be escorted by Gale force to Storm force winds in the outer
coastal waters, Clarence Strait, Southern Chatham and Cross Sound
will also increase to 35 kt as the front approaches. Much of the
rest of the inner waters will be 20 to 25 for Saturday and
Saturday night.

The southern half of the panhandle will get rain with some periods
of heavy rain rates, the central and north central will start as
snow and may mix with rain later part of Saturday and Saturday
night. The frontal orientation (NW-SE) will struggle to push
though the northeastern panhandle so that area should stay snow.
Accumulations of 4 to 11 inches total continue to be in the
forecast supporting the Winter storm warning. The nearby zones (
Yakutat, Gustavus ) will get 3 to 7 inches so Advisories are
issued. Hyder also looks like the precipitation will start as snow
with up to 10 inches. Confidence in the snow above average and
think the amounts will be close for this event.

Showers should continue for Saturday into early Sunday. The next
system will be approaching as pretty much on the track we were
thinking, although think the track may be shifting the majority
of the energy a touch further south. A similar pattern to the
similar Saturday system may be seen for Monday but we will be
looking at this system more over the next 24 hours.

.LONG TERM...As we pass the baton of the early weekend storm to
the short-range forecaster, we direct at least some of your
leftover attention to a winter event over the northern Panhandle
including the capital city and potentially parts of the central
Panhandle on Monday. And not to be left out, the southern
Panhandle looks to receive more heavy rain along with yet another
heavy round of snow in Hyder.

As is often the case, after Saturday's front passes Southeast,
poorly defined sub-features dominate the gulf in the long-wave
trough. One such wave approaches the southern or central
Panhandle on Sunday. Models vary on strength; ensembles all show
it. And depending on orientation, we may achieve a little
southerly warming through the southern and central Inner Channels.
Admittedly, this could affect the rain/snow line for Monday's
system, but until we can pass Saturday/Saturday night's system, we
will have to entertain theoretical possibilities and gear
Monday's forecast in terms of highest probabilities.

On the subject of Monday, a fast moving jet across the North
Pacific laden with some subtropical moisture will interact with
some Bering Sea baroclinicity Sunday/Sunday night. Confidence is
high in surface development of a deep low over the western Gulf of
Alaska with a gale to possibly storm force front thrusting
eastward into the eastern gulf. The front's northwest to southeast
orientation should aid cold air preservation across Icy Strait and
the Juneau area. For now, we have kept the strongest winds along
the coast and the southern Panhandle with the idea of blocked flow
or northerly flow within the boundary layer. Then we have strong
southerly flow overrunning this polar air mass across the
Panhandle with the result being another opportunity for heavy snow
potential Juneau, Gustavus, maybe Hoonah, and into Haines/Skagway
and maybe Yakutat. Our highest probability guess is around 8
inches. But obviously this could go either way. To the south where
both lift will be strongest and moisture the deepest, Hyder looks
primed for over a foot of snow Monday/Monday night. While rain is
more certain for Angoon, Kake, Petersburg, and Wrangell, snow is
not out of the question for some of these areas as well. Winds
still need to be ironed out, but we continued the trend of raising
wind speeds, both southerlies in the south and along the coast as
well as northerlies through Lynn Canal.

Leading into mid-week, the parent low slides southeast of our area
by most all-accounts and thus we begin to dry things out for the
north, especially Tuesday and into early Wednesday. For now, we
keep things cold. Confidence falls into late week, when we do not
have a strong sense of a succeeding ridge's duration. While there
is some indication of warming with a new system approaching late
in the week, confidence is low. Currently, we leave winds out of
Downtown Juneau, but there is potential for some gustiness in the
Taku regions of Juneau Tuesday as brief cold air advection ensues.

Confidence in Monday's winter event is high for this far out.
Again, the challenge will be warning about the monster behind the
corner while wrestling with Saturday's event.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind Saturday morning for AKZ026.
     Winter Storm Warning from 8 AM to 9 PM AKST Saturday for AKZ018-
     019-025.
     Strong Wind from late tonight through Saturday morning for
     AKZ022.
     Strong Wind Saturday morning for AKZ023.
     Winter Weather Advisory from 6 AM to 6 PM AKST Saturday for
     AKZ020.
     Winter Weather Advisory from 10 AM to 11 PM AKST Saturday for
     AKZ029.
     Winter Weather Advisory from 8 AM Saturday to 5 AM AKST Sunday
     for AKZ017.
MARINE...Storm Warning for PKZ043-051-052.
     Gale Warning for PKZ022-033-036-041-042.
     Small Craft Advisory for PKZ021-031-032-034-035-053.

&&

Bezenek/JWA

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