413 
FXAK67 PAJK 020009
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
309 PM AKST Fri Jan 1 2021

.SHORT TERM.../Through Sunday night/ An upper level trough 
bringing widespread showers today will move through the region by
this evening. A low pressure system moving in tonight is the 
eastern extent of a front that leads all the way back to the 
strong storm in the Aleutians. This surface low will reach the 
southern part of the panhandle by Saturday afternoon with a second
low arriving by Sunday evening. The second low will likely ride 
up and along the coast. 

Currently, a weak mountain wave event is occurring in downtown
Juneau, with gusts of up to 55 mph observed. Increased winds have
kept temperatures in the upper 30s in downtown Juneau. A second 
weak mountain wave event is forecasted for tomorrow, before winds 
calm down into Saturday evening. A strong northerly pressure 
gradient will stick around in the Northern Lynn Canal, producing 
north winds of 25 kts. Winds will decrease and switch to southerly
Sunday afternoon, but confidence on timing is low. Small craft 
expected for the outer coast, Clarence Strait, and the Lynn Canal 
tonight through Saturday. 
 
Precipitation has proven to be a mixed situation. Hyder had 
already seen around 7 inches of snow overnight and snow continues 
to fall. A winter weather advisory remains up for the Hyder area 
into Fri evening. Pops start to increase to likely this evening in
some areas (especially Juneau) and some accumulating snow 
(amounts around 1 to 3 inches) will start to show up as 
temperatures remain cold, though if the outflow remains strong 
precip amounts for the north may end up being less. 

Overall changes were mostly limited to local effects. Continued to 
use GFS and NAM for guidance today.

.LONG TERM.../Sunday through Thursday as of 10 PM Thursday/The
long term forecast begins with decent agreement about the 
placement of a low pressure just off the coast Sunday morning but
the strength of the low varies between models and model runs. 
Then another low looks to move in from the southwest Sunday night 
and Monday. But afterwards, the models descend into chaos.

But looking beyond the chaos, a general pattern can be found. 
From Monday afternoon through the rest of the week, it looks like 
a central parent low will form over the gulf and smaller lows will
spin around the central low. The takeaway from this general 
pattern is southeast Alaska is looking at an active first week of 
2021 with several rounds of wind and rain and snow possible.

Because of the very little model agreement, not many updates to
the forecast were made. Simply updating the forecast to blends of
the recent runs of the Canadian, GFS, and European models.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind through Saturday afternoon for AKZ025.
     Winter Weather Advisory until 9 PM AKST this evening for AKZ029.
MARINE...Gale Warning for PKZ043. 
     Small Craft Advisory for PKZ012-013-022-031-036-041-042-051>053. 

&&

$$

KRT/EAL/GJS

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