National Weather Service Raw Text Product

508 
FXAK67 PAJK 100008
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
308 PM AKST Tue Feb 9 2021

.SHORT TERM...A frigid air mass has parked across our region,
sending some of the coldest air in some parts in several winters.
Downtown Juneau and Douglas has only managed the mid-single 
digits. Skagway has failed to make it above zero as best we can 
tell. Petersburg and Wrangell have barely eclipsed above ten
degrees. Sitka and Ketchikan have been stuck in the teens all 
day. While normal and ho-hum in other parts of Alaska, in a region
dominated by mild onshore flow with consistent adjacent warm pools
through the Inner Channels, it is very impressive. But to place in
perspective, records have not been an issue, although close in 
some spots. Sounding climatology, too has been impressive with 
temperatures at 850 mb at Annette among the coldest ever seen for 
the date in the decades of data, -14 C. The cold has impacted 
some. Auke Bay elementary switched to online instruction due to a 
frozen pipe issue. 

Winds have presented an issue as well with strong wind gusts
reported in Downtown Juneau and Douglas as well as Skagway and the
Klondike Highway. Along with the frigid temperatures, estimated at
the teens below zero we have some serious wind chill issues at
White Pass. Given strong winds and persistent cold, we extend the
wind chill advisory at White Pass through 3 PM Wednesday afternoon
with a potential option later of extending it into Thursday. Will
other locations have wind chills? Certainly, we expect 20 below
around Juneau. Heavy freezing spray looks a solid bet through
Wednesday evening. Satellite confirms freezing spray through
portions of the Inner Channels and in outflow plumes across the
gulf. Near constant northerly gradients should support consistent
gales through Lynn Canal and small crafts in other northern Inner
Channels and Sumner Street. 

There could be some shallow training of light snow showers in
localized areas of northeast Chichagof, eastern Baranof,
Kupreanof, and Prince of Wales Island. Webcams confirmed, but
spotter calls have proven there has been little in the way to show
for it. Thus we think these bands will be too light to be 
impactful. Few changes were made as the forecasts looks good. 

.LONG TERM.../Thursday through Tuesday night/...Outflow winds
subside throughout the the first half of the period and any Taku
winds impacting Juneau and Douglas will subside, as well, as the 
high to our northeast in northwestern Canada weakens. It looks 
like the high could get as strong as 1064mb according to model 
guidance. It looks like southeast Alaska will have continued high 
and dry conditions through the weekend as it stays under the high 
pressure's dominance. Use extra caution, especially for the first
half of the forecast period due to the cold temperatures the very
low wind chills from what will be left of the outflow winds from 
the aforementioned strong high over northwestern Canada. For 
mariners, heavy freezing spray will be a possibility as well 
because of the strong winds and very cold temperatures. Dress and
make any other preparations accordingly. One positive note is 
that under the continued decreased cloudiness, there will be more 
opportunities to see the aurora as long as the space weather 
conditions are right.

Toward the end of the period, chances of light precipitation may 
return as the ridge begins to slowly break down and a storm system
approaches the Panhandle. The models are slowly coming into 
agreement for this solution, but the exact location and strength 
of the low are still to be determined. This begins to occur around
the Monday into Monday night timeframe. The ECMWF and the GFS 
have the low tracking to the south and impacting the southern 
Panhandle the most. The Canadian has it tracking toward the 
northern/central Panhandle. Shortly thereafter, a ridge looks to 
build in from the west for up to about a day and then another 
system looks to approach the area right around the Wednesday 
timeframe, just beyond our forecast period. Understandably, model 
agreement isn't that great on this, yet, as it is so far out in
time, but the agreement is there that there will be something 
impacting our area around the end of the period. The location and
strength of the system are still up in the air.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind through Wednesday afternoon for AKZ018-025.
     Wind Chill Advisory until 3 PM AKST Wednesday for AKZ018.
MARINE...Heavy Freezing Spray Warning for PKZ031. 
     Heavy Freezing Spray Warning for PKZ031. 
     Heavy Freezing Spray Warning for PKZ011. 
     Heavy Freezing Spray Warning for PKZ012-013. 
     Heavy Freezing Spray Warning for PKZ032. 
     Gale Warning for PKZ012-013-022. 
     Small Craft Advisory for PKZ011-021-031>034-043-051>053. 

&&

$$

JWA/JLC

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