Small Craft Advisory 233, NWS Juneau, AK

810 
FZAK53 PAJK 202327
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
327 PM AKDT Tue Apr 20 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.

PKZ053-211730-
Yakutat Bay-
327 PM AKDT Tue Apr 20 2021

.TONIGHT...W wind 10 kt becoming SE in the evening, then becoming
light late. Seas 7 ft. SW swell in the evening. Patchy fog late. 
.WED...E wind 10 kt in the morning becoming light. Seas
5 ft. Patchy fog in the morning. 
.WED NIGHT...Light winds. Seas 5 ft. 
.THU...Light winds. Seas 6 ft. SE swell. 
.THU NIGHT...Light winds. Seas 6 ft. SE swell. 
.FRI...NE wind 10 kt. Seas 6 ft. 
.SAT...NE wind 10 kt. Seas 5 ft. 
.SUN...N wind 10 kt. Seas 4 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
254 PM AKDT Mon Apr 19 2021

.SHORT TERM...Our period of sunny skies and record high temps is
having its last hurrah today, even with some sea breezes limiting
peak heating. A ridge of high pressure is expected build into the
eastern gulf tonight from the south. This will cause flow to turn
onshore. Clouds developing under the ridge, and those assoc with
a weakening front over the central gulf, will be pushed onshore
due to the changing flow. An upper level trough passing overhead
from SW to NE around midnight will help to increase clouds
further and cause some PVA/lift, leading to possible drizzle in
places that have low clouds in place at the time. Have backed
drizzle down to a chance based on how the high the clouds have
been so far, but marine layers often form in place and therefore
has lower confidence.

The ridge will sharpen over the eastern gulf on Tuesday, causing
winds to be more NWLY and along shore. This will help the marine
layer clouds to back off some through the afternoon. Another upper
level trough will track out of interior Alaska and across the
Yukon Tuesday night. This looks to cause mainly clouds again, but
have kept a slight chance or rain in the forecast tracking SE over
the region through Wed morning. The trough has much colder air
behind it (850mb temp of +5C today down to -4C across the north
Wed AM), so it's possible that the precip will be more convective
in nature. All models agree in clearing behind the trough from
north to south through Wednesday afternoon along with a northerly
pressure gradient setting up again.

.LONG TERM.../ Wednesday through Monday / A large blocking ridge
over the eastern Pacific extending into the Northwest portion of
Alaska continues Wednesday and Thursday. Part of an upper level
(500 mb) low, south of the central Aleutians, slides southeast.
As it does, the low continues to move southeast of the CONUS into
Saturday. The upper level ridge repositions to extend from the
north central pacific, through the gulf to Alaskan interior for
Sunday and Monday. The pattern Monday starts to look more chaotic
as another low from the Bering moves into the western gulf.

With the blocking pattern in place aloft, the forecast for SEAK
is expected to be dry. There may be a possibility of rain around
Friday night/early Saturday from a low in the gulf, or maybe some
drizzle along the coast from the marine layer on Wednesday.

Although conditions remain dry, sky cover may not remain as clear.
A marine layer is expected to push into Southeast Alaska Tuesday
night into early Wednesday. With this, temperatures are expected
to be cooler. Seasonal normals include Highs in the 50s to 60s.
The marine layer is expected to move offshore or be eroded by
Thursday and late Thursday into weekend as the potential for
sunshine returns. This being said don't think the temps will push
back to the warmth of the last couple days for SEAK.

Did not need to make much changes to the forecast package.
Forecast confidence is average to above average as a more stable
forecast pattern develops.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ041>043-051>053.

&&

Ferrin/Bezenek

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