Small Craft Advisory 25, NWS Juneau, AK

589 
FZAK51 PAJK 111325
CWFAJK

Coastal Waters Forecast for Southeast Alaska
National Weather Service Juneau AK
425 AM AKST Mon Jan 11 2021

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.

PKZ098-120330-
425 AM AKST Mon Jan 11 2021
.SYNOPSIS FOR SOUTHEAST ALASKA INNER CHANNELS COASTAL WATERS...
Low pressure lies stationary over the western gulf as
a ridge of high pressure persists across northern BC through 
Monday night. A storm force low lifts NW along the gulf coast 
Monday night and moves onshore near Cross Sound Tuesday afternoon.

$$

PKZ011-120330-
Glacier Bay-
425 AM AKST Mon Jan 11 2021

.TODAY...SE wind 15 kt. Seas 3 ft. Rain showers. 
.TONIGHT...SE wind 20 kt. Gusts to 35 kt in the evening. Seas
4 ft. Rain showers in the evening, then rain and snow late. 
.TUE...SE wind 20 kt increasing to 30 kt in the afternoon.
Seas 4 ft building to 6 ft in the afternoon. Rain showers and 
snow showers.
.TUE NIGHT...SE wind 15 kt. Seas 3 ft. Rain showers. 
.WED...SE wind 10 kt. Seas 2 ft or less. 
.THU...E wind 10 kt becoming N. Seas 2 ft or less. 
.FRI...SE wind 10 kt. Seas 2 ft or less. 

$$

PKZ012-120330-
Northern Lynn Canal-
425 AM AKST Mon Jan 11 2021

.TODAY...S wind 15 kt. Gusts to 35 kt in the afternoon. Seas
3 ft. Rain showers. 
.TONIGHT...N wind 15 kt. Seas 3 ft. Rain. 
.TUE...N wind 20 kt becoming SE 30 kt in the afternoon. Gusts
to 45 kt in the afternoon. Seas 4 ft building to 6 ft in the
afternoon. Rain showers.
.TUE NIGHT...SE wind 20 kt. Seas 4 ft. Rain showers. 
.WED...S wind 15 kt. Seas 3 ft. 
.THU...N wind 25 kt. Seas 5 ft. 
.FRI...S wind 15 kt. Seas 3 ft. 

$$

PKZ013-120330-
Southern Lynn Canal-
425 AM AKST Mon Jan 11 2021

.TODAY...S wind 20 kt. Gusts to 35 kt. Seas 4 ft. Rain showers. 
.TONIGHT...N wind 20 kt. Seas 4 ft. Rain. 
.TUE...N wind 20 kt becoming SE 30 kt in the afternoon. Seas
4 ft building to 6 ft in the afternoon. Rain showers. 
.TUE NIGHT...SE wind 15 kt. Seas 3 ft. Rain showers. 
.WED...S wind 15 kt. Seas 3 ft. 
.THU...NE wind 30 kt. Seas 6 ft. 
.FRI...S wind 20 kt. Seas 4 ft. 

$$

PKZ021-120330-
Icy Strait-
425 AM AKST Mon Jan 11 2021

...SMALL CRAFT ADVISORY LATE TONIGHT...

.TODAY...E wind 15 kt. Seas 3 ft. Rain showers. 
.TONIGHT...E wind 25 kt. Seas 5 ft. Rain. 
.TUE...SE wind 30 kt. Seas 6 ft. Rain showers. 
.TUE NIGHT...SE wind 20 kt. Seas 4 ft. 
.WED...E wind 15 kt. Seas 3 ft. 
.THU...E wind 30 kt. Seas 6 ft. 
.FRI...E wind 25 kt becoming SE 15 kt. Seas 5 ft subsiding to 3 ft.

$$

PKZ022-120330-
Cross Sound-
425 AM AKST Mon Jan 11 2021

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...E wind 15 kt. Seas 12 ft. Rain showers. Isolated 
thunderstorms. 
.TONIGHT...E wind 25 kt. Seas 13 ft. SW swell. Rain. Slight 
chance of thunderstorms in the evening. 
.TUE...E wind 30 kt becoming W in the afternoon. Seas 14 ft.
Rain showers. 
.TUE NIGHT...E wind 15 kt. Seas 11 ft. SW swell. Rain showers.
.WED...SW wind 20 kt becoming E. Seas 11 ft. 
.THU...E gale to 35 kt. Seas 12 ft. 
.FRI...SE wind 30 kt becoming S 20 kt. Seas 14 ft. 

$$

PKZ031-120330-
Stephens Passage-
425 AM AKST Mon Jan 11 2021

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...SE wind 20 kt. Gusts to 40 kt. Seas 4 ft. Rain showers. 
.TONIGHT...SE wind 25 kt. Gusts to 40 kt. Seas 5 ft. Rain.
.TUE...SE wind 25 kt. Seas 5 ft. Rain showers. 
.TUE NIGHT...SE wind 20 kt. Seas 4 ft. Rain showers. 
.WED...SE wind 20 kt. Seas 4 ft. 
.THU...S wind 30 kt. Seas 6 ft. 
.FRI...S wind 20 kt. Seas 4 ft. 

$$

PKZ032-120330-
Northern Chatham Strait-
425 AM AKST Mon Jan 11 2021

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...SE wind 15 kt increasing to 25 kt in the afternoon. Seas
3 ft building to 5 ft in the afternoon. Rain showers. 
.TONIGHT...SE wind 25 kt. Gusts to 40 kt. Seas 5 ft. Rain.
.TUE...SE wind 30 kt. Seas 6 ft. Rain showers in the morning.
.TUE NIGHT...SE wind 15 kt. Seas 3 ft. 
.WED...S wind 15 kt. Seas 3 ft. 
.THU...S wind 30 kt. Seas 6 ft. 
.FRI...S wind 25 kt diminishing to 15 kt. Seas 5 ft subsiding to 3
ft.

$$

PKZ033-120330-
Southern Chatham Strait-
425 AM AKST Mon Jan 11 2021

...GALE WARNING LATE TONIGHT...

.TODAY...S wind 20 kt. Gusts to 40 kt. Seas 4 ft, except 14 ft 
near ocean entrances. Rain showers and isolated thunderstorms. 
.TONIGHT...S wind 25 kt becoming SE 35 kt late. Seas 5 ft building
to 7 ft late. Near ocean entrances, seas 17 ft building to 22 ft 
late. Rain.
.TUE...S gale to 45 kt diminishing to 20 kt in the afternoon.
Seas 9 ft subsiding to 4 ft in the afternoon. Near ocean
entrances, seas 23 ft subsiding to 15 ft in the afternoon. Rain
showers in the morning. 
.TUE NIGHT...S wind 15 kt. Seas 3 ft, except 12 ft near ocean
entrances. 
.WED...SE wind 15 kt. Seas 3 ft. 
.THU...SE wind 30 kt. Seas 6 ft. 
.FRI...S wind 15 kt. Seas 3 ft. 

$$

PKZ034-120330-
Frederick Sound-
425 AM AKST Mon Jan 11 2021

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...SE wind 20 kt. Gusts to 40 kt. Seas 4 ft. Rain showers.
.TONIGHT...SE wind 30 kt. Gusts to 45 kt. Seas 6 ft. Rain.
.TUE...S gale to 40 kt diminishing to 20 kt in the afternoon.
Gusts to 55 kt in the morning. Seas 8 ft subsiding to 4 ft in the
afternoon. Rain showers. 
.TUE NIGHT...SE wind 15 kt. Seas 3 ft. 
.WED...SW wind 15 kt increasing to 25 kt. Seas 3 ft building to 5
ft.
.THU...E wind 30 kt. Seas 6 ft. 
.FRI...SE wind 20 kt. Seas 4 ft. 

$$

PKZ035-120330-
Sumner Strait-
425 AM AKST Mon Jan 11 2021

...GALE WARNING LATE TONIGHT...

.TODAY...SE wind 15 kt increasing to 25 kt in the afternoon.
Gusts to 40 kt. Seas 3 ft building to 5 ft in the afternoon, 
except 9 ft near ocean entrances. Showers.
.TONIGHT...E wind 30 kt becoming SE 40 kt late. Seas 6 ft building
to 8 ft late. Near ocean entrances, seas 10 ft building to 15 ft 
late. Rain.
.TUE...S wind 30 kt diminishing to 15 kt in the afternoon.
Seas 6 ft subsiding to 3 ft in the afternoon. Near ocean
entrances, seas 14 ft subsiding to 10 ft in the afternoon. Rain
showers. 
.TUE NIGHT...SE wind 15 kt. Seas 3 ft, except 7 ft near ocean
entrances. Rain showers. 
.WED...SE wind 15 kt. Seas 3 ft. 
.THU...SE wind 20 kt. Seas 4 ft. 
.FRI...SE wind 20 kt. Seas 4 ft. 

$$

PKZ036-120330-
Clarence Strait-
425 AM AKST Mon Jan 11 2021

...GALE WARNING TONIGHT...

.TODAY...S wind 25 kt. Gusts to 35 kt in the afternoon. Seas 5 ft,
except 8 ft near ocean entrances. Showers.
.TONIGHT...SE wind 35 kt. Seas 7 ft, except 13 ft near ocean 
entrances. Rain.
.TUE...S wind 25 kt. Seas 5 ft, except 10 ft near ocean 
entrances. Rain showers in the morning. 
.TUE NIGHT...S wind 15 kt. Seas 3 ft, except 8 ft near ocean 
entrances. 
.WED...S wind 25 kt. Seas 5 ft. 
.THU...SE wind 30 kt. Seas 6 ft. 
.FRI...S wind 20 kt. Seas 4 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
307 PM AKST Sun Jan 10 2021

.SHORT TERM.../Through Tue night/ Yet another front in a very long
series of weather systems is making its way through the gulf and
panhandle today. More rain and wind is the main story of the day,
though nothing really extreme. Highest gusts have been in the
southern panhandle with around 45 mph seen at Ketchikan so far.
The one exception was the Haines Highway which got buried in snow
overnight. Haines Customs station reported 23 inches of new snow
at 8 am this morning. They have since warmed up to 34 degrees as
of 1 pm and look to have changed over to rain.

The short range forecast is actually trending toward a quieter
period as there is only one more storm of note that will pass
through the area after tonight's front moves through. Otherwise SW
onshore flow and showers with some very minor short waves here and
there will rule the day. There is enough cold air aloft coming in
behind tonight's front that thunderstorms become a possibility for
the gulf waters and outer coast through Mon evening. A slight
chance of thunderstorms has been kept in the forecast for those
areas for that time.

The one storm of note shows up on Mon night/Tue as a 978mb low
riding north along the outer coast. Forecast confidence on this
low is about average, but is much better then yesterday. Current
guidance appears to have settled on the timing and track of the
feature, but remain at odds on how strong it will be (anywhere
from 970 from the Canadian to 981 from the GFS). The much better
agreement on timing and track has resulted in a change in the Mon
night to Tue forecast compared to previous with the system now
closer to the coast, later timing (now more late mon night rather
then mon evening), and bringing more wind to the panhandle later
in the night. Gusts of 40 to 50 mph now appear to be likely for
the southern panhandle and outer coast as this system passes by.
Another period of rain looks to be likely as well though nothing
really heavy at this time.

.LONG TERM.../Tuesday through Sunday night/...The long range
forecast period begins with a large upper low centered over
Bristol Bay, a much weaker upper circulation west of Haida Gwaii,
and a very broad upper trough which encompasses both of these
features. The base of the trough extends from the dateline east to
the west coast of southern British Columbia with the trough axis
extending south to 40N. A very strong 190kt upper jet associated
with this trough will begin to dig south of the Aleutians early in
the period, sharpening up the trough axis and inducing a
negatively tilted upper ridge across the southern Gulf by
Wednesday afternoon. This will produce a new upper low which will
take up a position over the western central Gulf by Friday
morning. As this happens, the upper ridge will continue to build
and then be displaced to the east as a trough axis pivots north
about the new low. The upper low will retrograde northwest and
become absorbed in the upper flow as large scale onshore flow
dominates the eastern Gulf Friday night heading into Saturday. The
extended range forecast will end with another upper low
approaching the central Gulf from the southwest on Sunday.

At the surface, a compact low will be located over the northwest
Gulf and be rapidly absorbed into the circulation of a much larger
surface feature located well to the west. Meanwhile, a high end
gale force low will be located southwest of Haida Gwaii. Impacts
from this low currently expected to be minimal as the strongest
winds are projected to be located on the southern side of the
circulation, well away from the southeastern Gulf. The next
impactful winds over the eastern Gulf are expected next Thursday
when the next gale force low pushes a front into the Gulf from the
southwest.

The sensible weather pattern will continue to be wet, as is
typical for this time of the year, with multiple fronts and waves
bringing plenty of precipitation. The general onshore pattern will
provide for continued warmer (relatively speaking) air such that
the precip type will be predominantly rain for lower elevations
except the far northern inner channels. There, daytime rain will
periodically give way to overnight snow. Only the highways will
remain reliably cold enough for consistent snow.

Model agreement continues to suffer and most changes were limited
to Tuesday and Tuesday night, where the 00Z ECMWF and 18Z NAM were
used as the basis for winds. Of note, the subsequent NAM model run
has very little resemblance to the previous run, seriously
eroding confidence in the forecast. Blended the 18Z GFS and 00Z
NAM for PoP and QPF with slightly more confidence.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind until 6 PM AKST this evening for AKZ023-026.
     Strong Wind until 9 PM AKST this evening for AKZ027-028.
     Winter Storm Warning until 6 AM AKST Monday for AKZ018.
MARINE...Gale Warning for PKZ035-036-041>043-051-052.
     Small Craft Advisory for PKZ021-022-031>034-053.

&&

EAL/PRB

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