Storm Warning 48, NWS Juneau, AK

453 
FZAK51 PAJK 030038
CWFAJK

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
338 PM AKST Wed Dec 2 2020

Southeast Alaska Inside Waters from Dixon Entrance to Skagway

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.

PKZ098-031530-
338 PM AKST Wed Dec 2 2020
.SYNOPSIS FOR SOUTHEAST ALASKA INNER CHANNELS COASTAL WATERS...
A front over the eastern gulf will drift over the inner channels 
Wednesday night with diminishing winds and seas. Another low will 
move northward into the southeast gulf Thursday night. 

$$

PKZ011-031530-
Glacier Bay-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...SE wind 25 kt diminishing to 15 kt late. Gusts to 40 
kt in the evening. Seas 5 ft. Rain.
.THU...SE wind 15 kt in the morning becoming light. Seas
3 ft in the morning then 2 ft or less. 
.THU NIGHT...Light winds. Seas 2 ft or less. 
.FRI...SE wind 10 kt. Seas 2 ft or less. Rain.
.FRI NIGHT...SE wind 15 kt. Seas 3 ft. Rain.
.SAT...SE wind 15 kt becoming SW. Seas 3 ft. 
.SUN...SE wind 15 kt. Seas 3 ft. 
.MON...S wind 10 kt. Seas 2 ft or less. 

$$

PKZ012-031530-
Northern Lynn Canal-
338 PM AKST Wed Dec 2 2020

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

.TONIGHT...S wind 25 kt. Gusts to 40 kt. Seas 5 ft. Rain.
.THU...S wind 20 kt becoming light in the afternoon. Seas 4 ft in
the morning then 2 ft or less.
.THU NIGHT...N wind 15 kt. Seas 3 ft in the evening then
2 ft or less. Rain.
.FRI...S wind 10 kt. Seas 2 ft or less. Rain.
.FRI NIGHT...NW wind 15 kt. Seas 3 ft. Rain.
.SAT...N wind 15 kt becoming SE. Seas 3 ft. 
.SUN...S wind 10 kt. Seas 2 ft or less. 
.MON...S wind 15 kt. Seas 3 ft. 

$$

PKZ013-031530-
Southern Lynn Canal-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...SE wind 25 kt. Gusts to 40 kt in the evening. Seas 5 
ft. Rain.
.THU...S wind 20 kt becoming light in the afternoon. Seas 4 ft in
the morning then 2 ft or less. Rain in the afternoon. 
.THU NIGHT...N wind 15 kt. Seas 3 ft. Rain.
.FRI...S wind 10 kt. Seas 2 ft or less. Rain.
.FRI NIGHT...N wind 20 kt. Gusts to 35 kt. Seas 4 ft. Rain.
.SAT...N wind 20 kt becoming SE. Seas 4 ft. 
.SUN...SE wind 15 kt. Seas 3 ft. 
.MON...S wind 15 kt. Seas 3 ft. 

$$

PKZ021-031530-
Icy Strait-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...SE wind 25 kt diminishing to 15 kt late. Seas 5 ft
subsiding to 3 ft. Rain.
.THU...SE wind 10 kt. Seas 2 ft or less. Rain in the
afternoon. 
.THU NIGHT...E wind 10 kt. Seas 2 ft or less. Rain in the
evening. 
.FRI...E wind 15 kt. Seas 3 ft. Rain.
.FRI NIGHT...E wind 20 kt. Seas 4 ft. Rain.
.SAT...E wind 20 kt. Seas 4 ft. 
.SUN...SE wind 20 kt. Seas 4 ft. 
.MON...S wind 20 kt. Seas 4 ft. 

$$

PKZ022-031530-
Cross Sound-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TONIGHT...E wind 30 kt becoming SW 20 late. Seas 19 ft subsiding
to 14 ft late. Rain.
.THU...SW wind 15 kt becoming NE in the afternoon. Seas
10 ft. SE swell. Rain in the afternoon. 
.THU NIGHT...NE wind 15 kt becoming SW late. Seas 8 ft. SE
swell. 
.FRI...E wind 15 kt. Seas 6 ft. SW swell. Rain.
.FRI NIGHT...E wind 25 kt. Seas 7 ft. SW swell. Rain.
.SAT...E wind 25 kt. Seas 10 ft. 
.SUN...SE wind 20 kt. Seas 15 ft. 
.MON...S wind 15 kt. Seas 17 ft. 

$$

PKZ031-031530-
Stephens Passage-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...SE wind 25 kt. Wind gusts to 40 kt in the evening. 
Seas 5 ft. Rain.
.THU...SE wind 15 kt diminishing in the afternoon. Seas 3 ft in 
the morning then 2 ft or less. Rain.
.THU NIGHT...S wind 10 kt. Seas 2 ft or less. Rain.
.FRI...SE wind 10 kt. Seas 2 ft or less. Rain.
.FRI NIGHT...SE wind 15 kt. Seas 3 ft. Rain.
.SAT...SE wind 15 kt. Seas 3 ft. 
.SUN...S wind 20 kt. Seas 4 ft. 
.MON...S wind 20 kt. Seas 4 ft. 

$$

PKZ032-031530-
Northern Chatham Strait-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...SE wind 25 kt diminishing to 15 kt late. Gusts to 45 
kt in the evening. Seas 5 ft. Rain.
.THU...SE wind 15 kt becoming light in the afternoon. Seas 3 ft 
in the morning then 2 ft or less. Rain in the afternoon. 
.THU NIGHT...Light winds. Seas 2 ft or less. Rain in the
evening. 
.FRI...S wind 10 kt. Seas 2 ft or less. Rain.
.FRI NIGHT...SE wind 20 kt. Gusts to 35 kt. Seas 4 ft. Rain.
.SAT...SE wind 20 kt. Seas 4 ft. 
.SUN...SE wind 15 kt. Seas 3 ft. 
.MON...S wind 15 kt. Seas 3 ft. 

$$

PKZ033-031530-
Southern Chatham Strait-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...S wind 30 kt diminishing to 15 kt late. Seas 6 ft. 
Near ocean entrances, seas 20 ft subsiding to 15 ft late. Rain.
.THU...SE wind 15 kt diminishing in the afternoon. Seas 3 ft in 
the morning then 2 ft or less. Near ocean entrances, seas 10 ft. 
Rain.
.THU NIGHT...S wind 10 kt. Seas 2 ft or less, except 8 ft
near ocean entrances. Rain in the evening. 
.FRI...S wind 10 kt. Seas 2 ft or less, except 8 ft near ocean
entrances. Rain.
.FRI NIGHT...E wind 15 kt. Seas 3 ft, except 12 ft near ocean
entrances. Rain.
.SAT...S wind 15 kt. Seas 3 ft. 
.SUN...S wind 20 kt. Seas 4 ft. 
.MON...S wind 20 kt. Seas 4 ft. 

$$

PKZ034-031530-
Frederick Sound-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...SE wind 25 kt. Wind gusts to 45 kt in the evening. 
Seas 5 ft. Rain.
.THU...SE wind 15 kt. Seas 3 ft. Rain.
.THU NIGHT...SE wind 15 kt. Seas 3 ft. Rain in the evening. 
.FRI...SE wind 10 kt. Seas 2 ft or less. Rain.
.FRI NIGHT...E wind 15 kt. Seas 3 ft. Rain.
.SAT...SE wind 15 kt. Seas 3 ft. 
.SUN...SE wind 20 kt. Seas 4 ft. 
.MON...S wind 20 kt. Seas 4 ft. 

$$

PKZ035-031530-
Sumner Strait-
338 PM AKST Wed Dec 2 2020

...SMALL CRAFT ADVISORY THROUGH THIS EVENING...

.TONIGHT...SE wind 25 kt diminishing to 15 kt late. Gusts to
40 kt in the evening. Seas 5 ft subsiding to 3 ft. Near ocean 
entrances, seas 12 ft subsiding to 8 ft late. Rain.
.THU...E wind 15 kt. Seas 3 ft. Near ocean entrances, seas 6 ft. 
Rain.
.THU NIGHT...SE wind 15 kt. Seas 3 ft. Rain.
.FRI...SE wind 15 kt. Seas 3 ft. Rain.
.FRI NIGHT...SE wind 20 kt. Gusts to 35 kt. Seas 4 ft, except
7 ft near ocean entrances. Rain.
.SAT...E wind 15 kt. Seas 4 ft. 
.SUN...SE wind 20 kt. Seas 4 ft. 
.MON...S wind 20 kt. Seas 4 ft. 

$$

PKZ036-031530-
Clarence Strait-
338 PM AKST Wed Dec 2 2020

...GALE WARNING THROUGH EARLY THIS EVENING...

.TONIGHT...SE wind 40 kt diminishing to 20 kt late. Seas 10 ft. 
Rain in the evening. 
.THU...SE wind 25 kt. Seas 8 ft. Rain.
.THU NIGHT...S wind 20 kt. Seas 8 ft. Rain.
.FRI...S wind 25 kt. Seas 8 ft. Rain.
.FRI NIGHT...SE wind 30 kt. Seas 12 ft, except 15 ft near
ocean entrances. Rain.
.SAT...SE wind 30 kt becoming S 20 kt. Seas 12 ft subsiding
to 7 ft. 
.SUN...S wind 25 kt. Seas 11 ft. 
.MON...S wind 25 kt. Seas 7 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
248 PM AKST Tue Dec 1 2020

.SHORT TERM.../Tuesday evening through Thursday/

***SIGNIFICANT DECEMBER STORM IMPACTING SOUTHEAST ALASKA***

An atmospheric river and associated storm force front continue to
batter Southeast Alaska with high winds, very heavy rain, and
snow. On the wet side of the story, copious amounts of moisture
have been streaming northward all the way from Hawaii due to a
strong baroclinic zone over the region and a very strong LLJ
around 75 kt. With IVT reaching max values for this time of year
(1000 kg/m/s) and high PW across much of the region, heavy rain is
expected to continue through tomorrow. The North central
Panhandle was upgraded to a Flood Advisory including the cities of
Juneau, Sitka, Gustavus, and Hoonah. As of 2 PM, 2 to 4 inches of
rain has fallen across much of the region with an additional 3 to
5 inches expected over the next 24 hours. Creeks and streams have
been spiking and are expected to reach bankful, especially where
the Flood Advisory is in effect. The main axis of heavy rain that
spread across the entire Panhandle today will become more
north/south oriented, shifting the axis of heaviest rain toward
the north and central Panhandle tomorrow. The south, including
Ketchikan and Misty Fjords may receive a 12 hour break in the rain
tomorrow afternoon. At the same time, a wave will ride up along
the stalled front that has been draped over the region. This wave
will move northward tomorrow and Thursday, then push the front
through the Panhandle...bringing an end to this extreme
atmospheric river event. (More rain is on the way with the next
system Thursday night into Friday).

On the windy side of the event... An intense 75 kt low level jet
has remained in place today pummeling the central Panhandle. High
Wind Warnings have been verifying through the day along the Outer
Coast from Sitka to Hydaburg and even to Ketchikan. As the
aforementioned wave moves northward tomorrow, the axis of
strongest winds (75 kt at 925 mb) will retrograde and push up the
outer coast, increasing surface winds once again with gusts over
60 mph. High Wind Warnings have been extended until midday
Wednesday for the outer coast of Prince of Wales and Baranof
Island including Hydaburg and Sitka. Put gusts to 55 mph in the
forecast for Yakutat and Juneau as confidence was not high enough
to include these areas in the High Wind Warning. Feel that the
main energy with this system will linger along the outer coast and
may not reach as far north as Yakutat or Juneau. Still would not
rule out a gust to 60 mph in those areas; however no warning will
be issued at this time. Regardless of the actual numbers, strong
winds will continue to batter much of the Panhandle through
tomorrow causing additional impacts.

On the winter side of the event... Winter Storm Warning was
allowed to expire as snowfall rates have diminished along the
Haines Highway. About a foot of snow fell near Haines Border
Customs today, a little less than forecasted due to the extremely
low snow ratios. The foot of snow melted down to about 2" of
liquid indicating snow to liquid ratios were near 6 to 1! Snow
will continue to fall along the highways; however snow levels are
expected to rise to over 3500 feet by tomorrow afternoon switching
most places over to rain. Low confidence in the snowfall and wind
forecast for Skagway to White Pass. Parallel gradient today
allowed winds along the Klondike Hwy and Skagway to become light
and switch north, allowing temperatures to drop to freezing and
changing rain over to snow. Guidance has been performing very
poorly in this area as they were indicating strong southerlies the
entire day. Have gone against guidance tonight, keeping winds
light and colder air entrenched for Skagway and White Pass. As the
gradient slightly kinks and becomes more N/S oriented tomorrow,
have southerly winds slowly developing and increasing through the
afternoon hours. This will warm temperatures and change most areas
over to rain. This is a low confidence forecast for Upper Lynn
Canal as guidance has been consistently poor.

Confidence in the overall forecast drops off Thursday into
Thursday night as the current system departs and another one moves
in from the south. Deterministic models disagree on the track and
strength of a low moving north from the Pacific and into the
region. Ensembles and the American models agree on a general track
of the low moving north out of the pacific, through the eastern
gulf and near the northeast gulf coast by Friday morning. This
track would spread rain northward once again through the region
Thursday night into Friday. Rainfall totals of a half to one inch
appear reasonable for this system with IVT values around 300
kg/m/s or less and PW values around average for this time of year.
Winds through the Southern Inner Channels may increase to small
craft levels as the low passes by late Thursday. More detail will
be put into this next system in the coming forecast packages as
the most focus today was put on the current atmospheric river.

.LONG TERM.../Thursday through Tuesday night/ The remains of the
atmospheric river are moving east over the coast mountains into
western Canada on Thursday. Trailing being the frontal band
moving out of the eastern Pacific and northward over the eastern
gulf, there is some minor positions differences
between the operational solution early Thursday, although they
seem to think landfall just southeast of Yakutat Thursday night.

Mid range models Trying to suggest yet another weak low Friday
over Haida Gwaii, and a larger ones somewhere of the central gulf
Later Friday. A larger and deeper low south of the Aleutians with
a chaotic placement of the lows near it. Overall the pattern for
SEAK is to stay on the 'wet side', with most of any precipitation
to fall as rain, but in much lighter amounts that is occurring for
the first part of the current week.

Forecast confidence is average for Thursday and below average for
Friday to Tuesday. Model agreement is the biggest reason for lack
of confidence.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Flood Watch through late Wednesday night for AKZ018-019-022-024-
     026>028.
     Strong Wind until midnight AKST tonight for AKZ026-028.
     High Wind Warning until noon AKST Wednesday for AKZ027.
     Strong Wind until 3 PM AKST this afternoon for AKZ027.
     Strong Wind from midnight AKST tonight through late tonight for
     AKZ024.
     High Wind Warning until 3 PM AKST this afternoon for AKZ025.
     Areal Flood Advisory until 8 AM AKST Wednesday for AKZ020-021-
     023-025.
     Strong Wind from midnight AKST tonight through Wednesday
     afternoon for AKZ025.
     Strong Wind Wednesday morning for AKZ022.
     High Wind Warning until noon AKST Wednesday for AKZ023.
     Strong Wind Wednesday afternoon for AKZ023.
     High Wind Warning until 9 PM AKST this evening for AKZ028.
     Winter Storm Warning until 5 PM AKST this afternoon for AKZ018.
     Strong Wind from Wednesday morning through Wednesday afternoon
     for AKZ017.
MARINE...Storm Warning for PKZ042-043.
     Gale Warning for PKZ022-033-036-041-051.
     Small Craft Advisory for PKZ011>013-021-031-032-034-035-052-053.

&&

CM/Bezenek

Visit us at http://www.weather.gov/Juneau

Preliminary Local Storm Report
NATIONAL WEATHER SERVICE JUNEAU AK
1212 AM AKST Wed Dec 2 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0400 PM     Avalanche        JUNEAU                  58.30N 134.42W
12/01/2020                                      AK   Fire Dept/Rescue

            Thane Road Avalanche. Slide reached road,did not cross.

&&

pboyd

Preliminary Local Storm Report
NATIONAL WEATHER SERVICE JUNEAU AK
441 AM AKST Wed Dec 2 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 PM     Flood            JUNEAU                  58.30N 134.42W
12/01/2020                                      AK   Official NWS Obs

            Jordan Creek 10.5 ft 7 pm 12/1. Moderate flood stage
            10.5.

0400 AM     Flood            JUNEAU                  58.30N 134.42W
12/02/2020                                      AK   Official NWS Obs

            Jordan Creek 11.2 ft at 4am 12/2. Flooding on Cascade St
            and flooding in Jordan Center Lot

&&

pboyd