Small Craft Advisory 226, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
245 PM AKDT Mon Apr 12 2021

.SHORT TERM.../Through Wednesday/ Rather active and wet day as a
front brings moisture to the area. Temperatures have warmed up
into the mid to upper 30s for quite a few areas this afternoon.
The result is that most of the observed precip has been in the
form of rain rather then snow with little in the way of snow
accumulations being observed. The winter weather advisories that
were out for parts of the northern panhandle today were cancelled
early as a result. The exception to that is the Yakutat area where
higher precip rates kept temperatures down closer to freezing and
thus produced more snow. Upwards of 6 to 8 inches of snow was
observed as of 1 pm, but it is starting to warm enough that the
snow is starting to melt and rain is starting to mix in. The
winter storm warning that is out is still expected to expire on
time at 4 pm this evening.

The rest of the short range mainly focuses on the continued
precipitation. First the rain from the initial frontal bands will
gradually diminish through Tue as the main forcing for it moves
into Canada. The development of a new low on the front farther
south brings the precip back to the W for late Tue night into Wed
with a focus mainly on the NE gulf coast. Continued warm air
advection, especially with this next low, will keep temperatures
warm enough that the ptype is expected to be all rain. Snow
levels will also be on the rise getting up to 2000 to 3000 feet by
Wed. Precipitation will then diminish, and temperatures will
overall continue to warm into Wed night as surface ridging begins
to poke into the area.

Southerly winds of 25 to 30 are blowing through the Lynn Canal
area this afternoon and will persist into this evening. Strong
wind gusts of 35 to 40 mph have been observed at Haines and
Skagway this afternoon as well. These winds should diminishing
this evening as the surface troughing in the Southern Yukon
weakens. Otherwise, the only other winds of note are the 25 to 30
kt winds out in the gulf associated with the lingering front which
should be diminishing overnight as well. Next batch of stronger
winds is with the next low coming up on Tue night. Gale force
winds (possible storm force near Cape Suckling) will be seen
across the gulf, but should stay far enough west that the inner
channels may only see breezy conditions from this front.

Overall changes mainly focused on the warming of temperatures
today that flipped precip type to be more rain across the north
tonight into Tomorrow. Otherwise, mostly minor changes overall.

.LONG TERM.../Wednesday through Monday/... The long term begins
with a sharp baroclinic zone over the gulf with waves of
precipitation moving northwards towards the NE gulf coast. High
pressure over BC will be creeping westward through the end of the
week, slowly pushing the bulk of the precipitation west and out of
the region. Wednesday is still expected to be the wettest day of
the long term as a low moving north into Prince William sound
swings a dying gale force front into the Northern Panhandle and NE
gulf coast. Guidance this evening has trended slightly eastward
with the front, keeping the chance for rain across the northern
half of the region through Wednesday afternoon. With the front
slightly eastward, increased winds across the northern gulf and
along the NE gulf coast to gales Wednesday morning. Expect winds
to rapidly diminish through the day as the front dissipates and
higher pressure takes over.

As the main storm track directs the bulk of the storms into the
northwest gulf by Thursday, a responding ridge blows up across
western North America and pumps up much appreciated spring-time
warmth (850 mb temps +2C to +8C) into Southeast Alaska through
the weekend. 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! Alas springtime sunshine will make a grand
appearance. With higher pressure over Canada and an inverted
trough forming over the Panhandle, expect light northerly flow to
persist through the weekend. Daily sea breezes will likely develop
Friday and Saturday afternoon as well.

Confidence remains fairly high that the endless winter weather
will finally be kicked out as a spring-time pattern takes hold of
the region. Good agreement exists among the deterministic models
and ensembles through the long term. Used a blend of models for
the start of the period then transitioned to WPC towards the
latter end.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind until 10 PM AKDT this evening for AKZ018.
     Winter Storm Warning until 4 PM AKDT this afternoon for AKZ017.
MARINE...Gale Warning for PKZ051-052.
     Small Craft Advisory for PKZ012-022-041>043-053.

&&

EAL/CM

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