Very strong pressure gradient between Whitehorse and Skagway along with good cross barrier flow at the mid levels from the east to induce increase lee side troughing on SEAK side of mountains. The Juneau area had a Taku from a moderate critical layer and very strong inversion and cross barrier flow.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS AJK wrote it up.
Very strong pressure gradient between Whitehorse and Skagway along with good cross barrier flow at the mid levels from the east to induce increase lee side troughing on SEAK side of mountains. The Juneau area had a Taku from a moderate critical layer and very strong inversion and cross barrier flow.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Juneau, AK wrote its last area forecast discussion before the first event at Feb 10, 5:51 AM AKST, 3 hours 31 minutes earlier.
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
551 AM AKST Wed Feb 10 2021
.SHORT TERM...Wednesday through Thursday Night...It's a very cold
morning at the Juneau forecast office. How cold you may ask?
Colder than a day old doughnut. As of the writing of this
discussion, the temperature is a crisp -14.0 F. Strong high
pressure over the Yukon has delivered a frigid air mass to our
region, sending some of the coldest air in many years across the
panhandle. The Juneau Airport recorded a below zero temperature
for the first time since 2009 and Ketchikan broke a record low
temperature for February 9 that stood since 1939.
Winds have been impressive as well, with wind gusts in excess of
40 mph continuing from Skagway down Lynn Canal into Stephens
Passage and northern Chatham Strait. Derived winds from SAR images
acquired over the past 24 hours depict the outflow event nicely,
as nearly constant northerly gradients continue to support gales
through Lynn Canal and small craft conditions in other northern
Inner Channels and Sumner Strait. A Wind Chill Advisory continues
for White Pass until 3 PM this afternoon with a potential option
later of extending it into Thursday. With all the wind and cold
around the area, other locations will experience impressive wind
chills around 20 below. A smattering of Heavy Freezing Spray
Warnings are also in effect across the inner channels, including
Glacier Bay, Lynn Canal, Stephens Passage. Freezing spray will
continue to be an issue through the remainder of the short term.
Satellite images confirm the freezing spray event across portions
of the Inner Channels and in outflow plumes across the gulf.
The high pressure system over the Yukon is forecast to move
southeast over BC today and tomorrow. This repositioning turns our
northerly pressure gradient to northeasterly. The results will be
slightly warmer temperatures in the slowly moderating air mass.
The wind will continue in the favored areas, including possible
Taku winds for Downtown Juneau and Douglas (see long term). Very
few changes were made to the existing forecast and confidence over
the short term period is very good.
.LONG TERM...Friday through Tuesday...As of 9 PM Tue...Little
change at the start of the extended with cool temps and outflow
continuing. Pattern begins to change this weekend as high pressure
that has been over YT begins to slide S through BC. There is
potential for Taku winds to develop as cross barrier flow
increases as the high moves through BC, so increased winds Fri
into Sat but confidence in timing and strength are low. Pattern
continues to change over the weekend with guidance showing a front
pushing into the gulf late this weekend into early next week. This
will bring increased chances of precip next week. Given the cold
airmass in place to start the extended and parent low progged to
stay W of AK peninsula, expect precip will be snow. Precip chances
increase heading into the middle of next week, but with it comes
some WAA so there could be a change from solid to liquid precip S
to N at the end of the extended. Overall forecast confidence
remains average.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind through this afternoon for AKZ025.
Strong Wind from this evening through late tonight for AKZ019.
Wind Chill Advisory until 9 AM AKST this morning for AKZ019.
Wind Chill Advisory until 3 PM AKST this afternoon for AKZ018.
Wind Chill Advisory from 9 PM this evening to 6 AM AKST Thursday
for AKZ018.
MARINE...Heavy Freezing Spray Warning for PKZ011-031.
Heavy Freezing Spray Warning for PKZ012.
Heavy Freezing Spray Warning for PKZ013.
Heavy Freezing Spray Warning for PKZ032.
Gale Warning for PKZ012-013.
Small Craft Advisory for PKZ011-022-031-041>043-051-052.
&&
BFL/BPC
Visit us at http://www.weather.gov/Juneau5 high wind. Local standard time, as filed.
Marine exchange observation at the Juneau AML dock reported a winds speed of 70 mph. at 2:52 pm.
Skagway airport reported a gust of 60 knots at 7:43 am.
Multiple gusts over 60 mph. Marine exchange observation at the Juneau AML dock reported 67 mph at 4:42 pm. Damage to chairlifts at local ski hill due to chairs flip over the cable overnight and then damaged by operations when started back up.
Skagway Airport reported occasional gusts up to 60 mph.
First peak gust occurred at Marine exchange observation at Juneau AML dock at 11:22 am with a gust of 68mph. Several more after that with the latest gust at 10:22 pm.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2021Every state in 2021This day in weather historyWarnings in Alaska, February 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 945665, 945667, 945674, 945682, 945680.