Small Craft Advisory 169, NWS Juneau, AK

410 
FZAK53 PAJK 191142
CWFYAK

Marine Forecast for Yakutat Bay
National Weather Service Juneau AK
342 AM AKDT Fri Mar 19 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.

PKZ053-200545-
Yakutat Bay-
342 AM AKDT Fri Mar 19 2021

.TODAY...NE wind 15 kt diminishing in the afternoon. Seas 6 ft. S
swell. Snow showers early in the morning. 
.TONIGHT...NE wind increasing to 20 kt in the evening. Seas 7 ft.
S swell in the evening.
.SAT...NE wind 20 kt. Gusts to 35 kt. Seas 5 ft. 
.SAT NIGHT...NE wind 25 kt. Seas 5 ft. S swell. Snow.
.SUN...E wind 10 kt. Seas 7 ft. 
.MON...E wind 15 kt. Seas 7 ft. 
.TUE...E wind 15 kt. Seas 6 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
235 PM AKDT Thu Mar 18 2021

SHORT TERM...Most of the northern panhandle saw some blue skies
today, but another low pressure system brings precipitation back,
with Yakutat receiving snow showers through today. A stronger low
pressure system off the coast of Washington state has kept a
lower ceiling and areas of rain showers over the southern
panhandle.

The northern gulf low is bringing colder continental air and
several inches of snowfall into the northern panhandle. A winter
storm warning remains in effect from 8 pm this evening to 1 pm
Friday for Elfin Cove and Pelican. Other regions, including
Sitka, Juneau, Gustavus, Haines, and Yakutat, will receive
advisory level snowfall tonight. The snow has already started in
Yakutat and will move SE, reaching Sitka by midnight tonight. The
bands of snowfall may be quite localized and heavy at times.
Training of successive snow showers is another concern especially
in the Cross Sound region where the warning is posted.

Winds were increased today for another low pressure system
tracking towards the panhandle on Saturday. Current models
indicate strong offshore flow Saturday evening and winds were
increased in the Northern Lynn Canal and Clarence Strait regions.
Temperatures were nudged colder for Saturday evening into Sunday
due to 850 mb temperatures and an upper level trough.

Confidence for localized snow amounts is not high at this time,
but confidence that precipitation starts as snow for much of the
region is high. Confidence is increasing that some parts of the
northern and central Panhandle could see impactful snowfall
Saturday afternoon through Sunday morning before a transition to
rain is expected. NamNest wind magnitudes were used to increase
the strength and denote the offshore flow of Saturday's system.

LONG TERM..../Saturday through Thursday as of 10 PM Wednesday/
Guidance continues to support an active pattern through the long
term. Latest operational runs as well as ensemble guidance have
remained locked on to a few significant features through the
extended period. The first system exits the Bering Sea and tracks
into the Gulf this weekend. This system will bring widespread
precipitation across the panhandle Saturday and Sunday. Timing and
track of the low are still uncertain but confidence that this
system will bring widespread precipitation has increased. As for
ptype, the usual snow changing over to rain with the southerly
wind push looks likely. Areas through the Icy Strait corridor and
through upper lynn canal are expected to stay snow the longest.
Greatest qpf values look to fall across the southern panhandle
during Sunday. By Tuesday, a second low will track north out of
the Pacific Ocean. This system looks to have strong southern
moisture support allowing for yet another round of widespread
precipitation being heavy at times. Latest guidance suggest a
further south track compared to previous runs putting the
greatest qpf across the southern panhandle. Integrated water vapor
transport tables show values around 800 along with both NAEFS and
ECMWF standardized anomaly tables showing between 2-3 standard
deviations for this system. Snow levels also look to rise above
5,000 ft across parts of the central and southern panhandle.
Granted this event is a ways out, continued monitoring will be
needed for potential hydro impacts. In between these features,
confidence decreases as timing, strength, and placement vary from
model to model. Similar to previous forecast, a blend of
GFS/ECMWF/WPC was used.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory from 1 AM to 7 PM AKDT Friday for AKZ023-
     025.
     Winter Storm Warning from 8 PM this evening to 1 PM AKDT Friday
     for AKZ022.
     Winter Weather Advisory from 10 PM this evening to 1 PM AKDT
     Friday for AKZ019-020.
     Winter Weather Advisory until 5 AM AKDT Friday for AKZ017.
MARINE...Small Craft Advisory for PKZ022-041>043-051>053.

&&

KRT/CC

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