Small Craft Advisory 223, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
240 PM AKDT Sun Apr 11 2021

.SHORT TERM.../Through Tue/ The wedge of cold air in the northern
panhandle from yesterday is still there though not as strong as it
was. Temperatures have managed to get up into the low to mid 30s
this afternoon in these areas. The interaction between this and
the light southerly flow across the rest of the panhandle is
producing some clouds and light snow from Gustavus and Juneau
southward to Angoon. Precip has been very light however with
little to no snow accumulation observed. Southerly winds are
starting to appear in the Lynn Canal area with Haines and Skagway
just starting to blow out of the SE and S respectively.

Main short range forecast concern is the incoming front for
tonight into tomorrow and how much snow various areas of the north
will get. Temperatures in the north continue to run noticeably
below guidance this afternoon and that trend is expected to
continue into tomorrow. The result is more snow for many areas
north of Sitka and Angoon. Yakutat remains under a winter storm
warning tonight into tomorrow. New to the collection of headlines
are winter weather advisories for Juneau, Gustavus, Elfin Cove,
and Pelican for around 3 to 5 inches of new snow. Other areas are
not expected to get as much mainly due to terrain shadowing. The
snow is expected to change to rain sometime Mon for most areas,
but the timing varies from as early as the morning hours to as
late as Mon evening. 850 mb temperatures tend to stay in the -6
degree range through the afternoon in the northern inner channels
so current thinking is more toward the later time period for
change over rather then earlier, but confidence is around average
to low on this. Naturally, when this change over occurs will have
a large effect on observed snow totals drastically lowering or
raising them according. After changing to rain the precip will
continue into Tue but at at a lower intensity as warm air
continues to be pumped into the area.

Not much in the way of wind with this system. Northern gulf winds
will be picking up into the min gale force category late tonight
into tomorrow, but beyond that mainly 25 to 30 kt winds or less
are expected for many areas as the front approaches. Breezy
conditions will likely continue for many areas into Tue as the
front lingers in the area. Another blast of gale force winds for
the northern gulf will come on Tue night as the next wave along
the front moves north.

.LONG TERM.../Tuesday through Saturday/...As the tail end of an
plume of moisture continues into the northern and central
Panhandle Tuesday, thickness numbers seem to indicate that we will
have finally switched to rain at most locations at sea level by
Tuesday morning. Of course one spot, where we will watch is White
Pass. Potentially the Haines Highway could see a slower warmup
than what is currently forecast, but for now, we are keeping a
cold rain across Haines. The energy of the atmospheric river
continues to trend westward into mid-week, as southwest flow aloft
becomes more meridional. Thus Yakutat looks to receive the most
QPF with this system. The southern Panhandle on the contrary will
see best chances of dry weather. Given how warm thicknesses will
be and how late past the vernal equinox, fifty degrees in
Ketchikan looks increasingly likely Tuesday, and it should feel
marvelous.

As the main storm track directs the bulk of the storms into the
northern and northwest gulf into mid-week, a responding ridge
blows up across western North America and pumps up much
appreciated spring-time warmth into Southeast Alaska through the
rest of the week. Thus look for a broad and remarkable warming
trend day by day. As Juneau and the northern Panhandle approaches
50 degrees by Friday, Prince of Wales Island and Ketchikan may see
60. It's about time! Were temperatures not such the headline, we
should also mention that the upper level ridge across western
Canada should keep any storms well out to see. Alas springtime
sunshine will make a grand appearance.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory from 4 AM to 4 PM AKDT Monday for AKZ025.
     Winter Weather Advisory from 1 AM to 1 PM AKDT Monday for AKZ020-
     022.
     Winter Storm Warning until 4 PM AKDT Monday for AKZ017.
MARINE...Gale Warning for PKZ051-052.
     Small Craft Advisory for PKZ012-022-041>043-053.

&&

EAL/JWA

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

Special Weather Statement
National Weather Service Juneau AK
243 PM AKDT Sun Apr 11 2021

AKZ018-019-021-024-121300-
Taiya Inlet and Klondike Highway-Haines Borough and Lynn Canal-
Eastern Chichagof Island-
Eastern Baranof Island and Southern Admiralty Island-
Including the cities of Skagway, Haines, Hoonah, and Angoon
243 PM AKDT Sun Apr 11 2021

...MORE ACCUMULATING SNOW POSSIBLE...

Snow accumulations possible Sunday night into Monday across the
Central and Northern Panhandle. Warmer air and rising snow levels
will lead to a transition to rain Monday afternoon through
Tuesday. Low confidence exists in the exact timing of the
changeover from snow to rain, which could significantly impact the
snowfall forecast. Visit weather.gov/juneau for the latest
forecast updates.