Alert archive / Alaska / Small Craft Advisories in 2021

Small Craft Advisory 190, NWS Juneau, AK

March 29, 2021

NWS Juneau, AK issued this small craft advisory at Mar 29, 2021, 3:51 AM AKDT. It was in force for 3 days.

The area

The counties it named.

The facts

Issued
Mar 29, 2021, 3:51 AM AKDT (11:51 UTC)
Expired
Apr 1, 2021, 3:42 PM AKDT
In force
3 days
Issued by
NWS Juneau, AK

The text

As transmitted.

859 
FZAK53 PAJK 291151
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
351 AM AKDT Mon Mar 29 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-300600-
Yakutat Bay-
351 AM AKDT Mon Mar 29 2021

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

.TODAY...E wind 10 kt. Seas 7 ft. S swell in the afternoon. Snow,
rain.
.TONIGHT...Light winds becoming SW 15 kt late. Seas 10 ft. Rain.
.TUE...Light winds becoming SE 10 kt in the afternoon. Seas
8 ft. Rain.
.TUE NIGHT...SE wind 15 kt. Seas 8 ft. Rain and snow. 
.WED...E wind 15 kt becoming S. Seas 8 ft. 
.THU...E wind 10 kt. Seas 7 ft. 
.FRI...E wind 10 kt becoming light. Seas 5 ft. 

$$
7 follow-up statements
499 
FZAK53 PAJK 292326
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
326 PM AKDT Mon Mar 29 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-301730-
Yakutat Bay-
326 PM AKDT Mon Mar 29 2021

...SMALL CRAFT ADVISORY THROUGH TUESDAY...

.TONIGHT...Light winds becoming SW 15 kt late. Seas 8 ft. Rain.
.TUE...Light winds becoming SE 10 kt in the afternoon. Seas
8 ft. Rain.
.TUE NIGHT...SE wind 15 kt. Seas 8 ft. Rain.
.WED...E wind 15 kt. Seas 8 ft. Rain showers. 
.WED NIGHT...S wind 10 kt. Seas 8 ft. Rain showers. 
.THU...E wind 10 kt. Seas 7 ft. 
.FRI...E wind 10 kt becoming light. Seas 5 ft. 
.SAT...Light winds. Seas 3 ft. 

$$
673 
FZAK53 PAJK 301157
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
357 AM AKDT Tue Mar 30 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-310600-
Yakutat Bay-
357 AM AKDT Tue Mar 30 2021

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

.TODAY...SW wind 10 kt early in the morning becoming light, then
becoming SE 10 kt in the afternoon. Seas 9 ft. Rain.
.TONIGHT...SE wind 15 kt. Seas 10 ft. Rain.
.WED...SE wind 10 kt. Seas 9 ft. Rain.
.WED NIGHT...S wind 10 kt. Seas 8 ft. 
.THU...E wind 10 kt. Seas 7 ft. 
.FRI...E wind 10 kt becoming light. Seas 5 ft. 
.SAT...Light winds becoming E 10 kt. Seas 5 ft. 

$$
489 
FZAK53 PAJK 302319
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
319 PM AKDT Tue Mar 30 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-311730-
Yakutat Bay-
319 PM AKDT Tue Mar 30 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TONIGHT...E wind 15 kt. Seas 11 ft. Rain.
.WED...SW wind 10 kt. Seas 9 ft. Rain in the morning. 
.WED NIGHT...S wind 10 kt becoming NE late. Seas 7 ft. 
.THU...NE wind 10 kt. Seas 7 ft. S swell. 
.THU NIGHT...NE wind 10 kt. Seas 7 ft. S swell. 
.FRI...E wind 10 kt becoming light. Seas 5 ft. 
.SAT...Light winds becoming E 10 kt. Seas 5 ft. 
.SUN...Light winds. Seas 5 ft. 

$$
387 
FZAK53 PAJK 311121
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
321 AM AKDT Wed Mar 31 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-010530-
Yakutat Bay-
321 AM AKDT Wed Mar 31 2021

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

.TODAY...SW wind 20 kt. Seas 9 ft. Rain early in the morning. 
.TONIGHT...S wind 10 kt becoming light. Seas 7 ft. 
.THU...NE wind 10 kt in the morning becoming light. Seas
7 ft. SW swell in the afternoon. 
.THU NIGHT...NE wind 10 kt. Seas 7 ft. SW swell. 
.FRI...E wind 10 kt becoming light. Seas 6 ft. 
.SAT...Light winds becoming E 10 kt. Seas 5 ft. 
.SUN...E wind 10 kt becoming light. Seas 5 ft. 

$$
233 
FZAK53 PAJK 312323
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
323 PM AKDT Wed Mar 31 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-011730-
Yakutat Bay-
323 PM AKDT Wed Mar 31 2021

...SMALL CRAFT ADVISORY THROUGH THURSDAY MORNING...

.TONIGHT...SE wind 10 kt. Seas 9 ft. Rain showers in the evening.
.THU...E wind 10 kt in the morning becoming light. Seas
8 ft subsiding to 7 ft in the afternoon. 
.THU NIGHT...NE wind 10 kt. Seas 6 ft. SW swell in the
evening. 
.FRI...N wind 10 kt. Seas 5 ft. 
.FRI NIGHT...Light winds. Seas 5 ft. 
.SAT...Light winds becoming E 10 kt. Seas 5 ft. 
.SUN...E wind 10 kt becoming light. Seas 5 ft. 
.MON...NE wind 10 kt becoming light. Seas 6 ft. 

$$
504 
FZAK53 PAJK 011137
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
337 AM AKDT Thu Apr 1 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-020545-
Yakutat Bay-
337 AM AKDT Thu Apr 1 2021

...SMALL CRAFT ADVISORY THROUGH THIS MORNING...

.TODAY...E wind 10 kt early in the morning becoming light. Seas
8 ft. 
.TONIGHT...NE wind 10 kt. Seas 6 ft. SW swell. 
.FRI...E wind 10 kt in the morning becoming light. Seas 6 ft. 
.FRI NIGHT...Light winds. Seas 5 ft. 
.SAT...E wind 10 kt. Seas 4 ft. 
.SUN...E wind 10 kt becoming light. Seas 5 ft. 
.MON...E wind 10 kt. Seas 5 ft. 

$$
942 
FZAK53 PAJK 012342
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
342 PM AKDT Thu Apr 1 2021

Coastal Waters Forecast for Yakutat Bay

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.

PKZ053-021745-
Yakutat Bay-
342 PM AKDT Thu Apr 1 2021

.TONIGHT...Light winds becoming NE 15 kt late. Seas 7 ft. SW
swell in the evening. 
.FRI...NE wind 15 kt in the morning becoming light. Seas 6 ft.
.FRI NIGHT...Light winds. Seas 5 ft. 
.SAT...E wind 10 kt. Seas 4 ft. 
.SAT NIGHT...Light winds. Seas 4 ft. Snow and rain. 
.SUN...E wind 10 kt becoming light. Seas 5 ft. 
.MON...E wind 10 kt. Seas 5 ft. 
.TUE...E wind 10 kt. Seas 5 ft. 

$$

What forecasters said that day

The local office's own words before this small craft advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Juneau, AK wrote its last area forecast discussion before this small craft advisory went out at Mar 28, 2:55 PM AKDT, 12 hours 56 minutes earlier.

Area forecast discussion, Mar 28, 2:55 PM AKDT, 12 hours 56 minutes before
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
255 PM AKDT Sun Mar 28 2021

.SHORT TERM.../Sunday evening through Wednesday morning/
Northwest flow responsible for the drying trend across Southeast
Alaska Monday afternoon will be short lived as flow becomes
onshore later tonight. Northerly outflow winds will quickly
diminish through the Inner Channels by midnight tonight. Winds
turn southerly by Monday afternoon; however conditions should
remain under small craft levels for the Inside Passage.

A strengthening baroclinic zone between a ridge over the north
pacific and a digging trough over the Bering will put the region
in persistent westerly flow over the next couple days. A weak area
of low pressure developing in the northern gulf combined with
flow coming off the water will allow moisture to quickly stream
back into the Panhandle. Periods of precipitation move in from NW
to SE early Monday and continue through the rest of the short
term. With westerly flow setting up, the colder, drier air at the
surface will slowly erode away through the day. Expect P-type to
start as snow for the entire Panhandle, mixing with rain first
along the coast then inland through the afternoon and evening.
Minor snowfall accumulations possible from Petersburg to Sitka and
northward. A general 1 to 2 inches is expected with isolated
higher amounts up to 2 to 4 inches possible in Juneau. Expect
Upper Lynn Canal to be rain shadowed in this type of westerly flow
pattern, so have lowered POPs and QPF significantly for that
area. A complete changeover to rain should occur for most places
by Monday evening, and stay rain through Tuesday afternoon. The
most persistent rainfall will be focused along westerly facing
slopes, with periods of rain elsewhere. Rainfall amounts through
Tuesday will range from a quarter to a half inch across the south
to over an inch along the terrain of Baranof Island and the Coast
Mountains.

The next weather system arrives late Tuesday into early Wednesday
morning as a surface low develops in the northern gulf in
response to a digging trough moving SW out of the Bering. A minor
atmospheric river sets up ahead of this next system as strong
100+ kt jet transports ample moisture northward from the central
Pacific into Southeast Alaska. Heaviest precipitation will begin
across the NE Gulf coast Tuesday afternoon and evening, then slide
southeastward across the rest of the Panhandle Tuesday night into
Wednesday morning. 1000-850mb Thickness values drop to around
1290m just ahead of this system Tuesday afternoon and evening as
cooler air (-7 to -8C at 850mb) moves in aloft. There is a
possibility that precipitation may start as a brief period of snow
before warmer, southerly flow transitions everything to rain.
Rainfall amounts of 1 to 2 inches possible from Tuesday morning
through Wednesday morning across the northern half of the
Panhandle. Rain and snowfall amounts will be monitored closely
over the next few days, expect minor adjustments to them in future
forecast packages as the finer details become clearer.

Overall confidence is at or above average for the short term. For
Wind, POP and QPF used a blend of the NAM/GFS, more of the NAM
during the first 24 hours of the forecast.

.LONG TERM.../Tuesday through Sunday as of 10 pm Saturday/ The
extended range forecast features a shifting upper level pattern in
the middle of next week. A rather flat upper level ridge over the
area on Tue will get replaced by a cold upper through that moves
in from the W. This trough sort of stalls over the area late week
and persists into the weekend. No disagreement from guidance on
this other then how strong that trough will eventually become by
the weekend and whether or not a reinforcing shot of cold air
will help keep the trough in place into the late weekend.

Lower in the atmosphere, the overall theme of the forecast is wet
with a cooling trend into the weekend. The wettest (and also
warmest period) is from Tue into Wed as the flat ridge both aloft
and at the surface allows a weak atmospheric river to bring
precipitation to the area. This culminates in a more organized
frontal band developing over the Gulf on Tue night, with it
sweeping through the panhandle on Wed. There are a few new
forecast developments with this system over the previous forecast.
First guidance has this front moving through the panhandle quicker
then previously forecast (the heavier frontal precip now is out
of the panhandle by Wed evening). This results in less rainfall
now expected for various areas. The wind forecast was also
affected by this timing change with the higher winds now moving
through at in a quicker timeframe. The second development is a
warm up noted (especially for the northern inner channels) from
the southerly flow ahead of the front. This has resulted in
warming some overnight lows on Tue night for quite a few areas.
There now is a larger area of the panhandle that stays above
freezing Tue night with more rain apparent in the new forecast.
Forecast for this frontal band remains uncertain as guidance
shifts timing and speed of the system.

Past Wed night, a low lingers in the northern gulf sending
westerly onshore flow and showers into the panhandle for the late
week while the incoming upper trough drags colder air into the
region. The northern half of the panhandle at least will likely
see these showers mostly in the form of snow as 850 mb temps drop
into the -8 to -9C range with some accumulations possible.
Forecast becomes increasingly uncertain rapidly into the weekend
as differences on how the upper trough and the northern gulf
surface low evolves with everything from continued showers to a
drying and warming trend possible.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Small Craft Advisory until 7 PM AKDT this evening for AKZ019-025.
MARINE...Small Craft Advisory for PKZ012-013-022-031>036-041>043-051-052.

&&

CM/EAL

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

The office that day

Everything else NWS Juneau, AK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 29, 4:21 AM AKDTWinter Weather AdvisoryAJK54 hr
Mar 29, 3:33 PM AKDTSmall Craft AdvisoryAJK48 hr

Nearby

Small Craft Advisories in Alaska, 2021Every small craft advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text.