Winter Weather Advisory 3, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
310 PM AKST Mon Jan 4 2021

.SHORT TERM...The next system to impact SE Alaska is steadily
making its way northward, with its center currently located west
of Baranof Island. Observations throughout the day have reflected
the stronger winds and the rain which this system has already
brought to much of the southern and central panhandle. As the
system moves northward, it will bring rain and snow for more
northerly parts of the area beginning Monday evening. Outflow
should reduce precip as it progresses toward the colder, northern
panhandle through the overnight hours on Monday. As this first
system rolls through, the Icy Strait Corridor Northward looks
favored to receive between 1-3 inches. Juneau could receive
between 1-4 inches. Model discrepancies continue to lead to lower
forecast confidence, and consequently, some locations could
experience pockets of greater or lower snow accumulation. In
Juneau in particular, the timing of the increase in strong
southerly flow will determine how long the snow lasts. A later
onset of the wind could see more snow falling, while an earlier
onset could result in only minimal snow accumulations.

While there is no real lull in precip in the current forecast,
most locations warm up enough during the day on Tuesday to see a
transition to rain or at least a wintry mix. The far northern
locations of Haines and Skagway probably miss out on the warm up.
Haines and the Haines Highway in particular looks likely to
receive up to 4 inches of snow on Tuesday. Issued a winter
weather advisory to reflect this. A strong frontal band will move
northward through the panhandle on Tuesday, bringing with it storm
force winds to some of the other coastal waters, and high wind
warnings to the southern panhandle and Sitka. Besides the winds,
this system will also bring with it further rain and snow.
Currently kept totals below advisory level for most of the
panhandle, barring Haines. However, forecast confidence is low,
and slight variations in temperature and windfall forecast in
either direction will lead to substantial differences in
accumulation.

.LONG TERM.../Wednesday through Sunday as of 10PM Sunday/The
specifics of the long term forecast are still in the air as there
is still a bit of inconsistency within the models. That being
said, the general idea can still be summed up as an active
forecast for southeast Alaska.

Wednesday looks to start off morning temps mostly in the 30s.
Areas in the far north, Haines/Skagway/Northern Lynn Canal, may
start off just a touch cooler, in the 20s. The afternoon looks to
warm to the 30s to low 40s under a generally southeast/onshore
flow.

Using a blend of the NAM, GFS, and Canadian models, there looks
to be an area of low pressure that will sit over the central gulf.
This low would push a gale force front northward across the gulf
and along the coast late Wednesday and Wednesday night. Strong
winds would be expected over the open waters with rain and snow in
the panhandle.

The rest of the forecast, from Thursday through the weekend, looks
busy with 3 more weather fronts that would move northward through
the area. The catch is, confidence in the timing and strength of
each individual front is low. But the overall pattern keeps a general
onshore pattern which would keep rain and snow in the forecast
and temperatures generally steady - lows mostly in the 30s and
highs in the 30s to 40s. We would also see the winds pick up,
especially along the coast, with each passing weather front.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind until 9 PM AKST this evening for AKZ026.
     High Wind Warning from 8 AM to 4 PM AKST Tuesday for AKZ023-027-
     028.
     Strong Wind until midnight AKST tonight for AKZ027.
     Strong Wind from late tonight through Tuesday morning for AKZ027.
     Strong Wind until 3 PM AKST this afternoon for AKZ018-025.
     Strong Wind through Tuesday morning for AKZ023-028.
     Winter Weather Advisory from 6 AM to 6 PM AKST Tuesday for
     AKZ019.
MARINE...Storm Warning for PKZ041>043.
     Gale Warning for PKZ022-033-036-051-052.
     Small Craft Advisory for PKZ012-013-021-031-032-034-035-053.

&&

GFS/GJS

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