Moist marine air over ran cold air that had moved in over Southeast Alaska from the interior of the continent. This created a snowfall event with high snow ratios.
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.
Moist marine air over ran cold air that had moved in over Southeast Alaska from the interior of the continent. This created a snowfall event with high snow ratios.
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 2, 2:58 PM AKST, 9 hours 47 minutes earlier.
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
258 PM AKST Tue Feb 2 2021
.SHORT TERM.../Tuesday evening through Thursday/ The dry weather
on Tuesday won't last long as the next winter storm moves in by
Wednesday morning. Guidance has been in great agreement over the
past few days showing a weak area of low pressure and associated
front moving east through the gulf and into the Central
Panhandle. With a cold air mass already in place across much of
the region, expect precip to start as snow for most areas early
Wednesday morning. Weak southerly flow ahead of the system will
slowly erode the arctic airmass at the surface allowing
temperatures to gradually rise through the day across the Central
and Southern Panhandle. 1000-850mb thickness rise above 1290m from
E to W during the afternoon hours from around Sitka to Angoon
southward, indicating a complete changeover to rain in the
southern half of the Panhandle at sea level. With the low tracking
right into Sitka, a persistent northerly gradient across the
northern half of the area will keep the arctic airmass locked in
place. Model soundings continue to show a very stable temperature
profile, so not expecting "warmer" air from southerly flow aloft
to mix down to the surface. This is a classic set up for heavy
snow across portions of the northern Panhandle, including Juneau.
Due to strong northerly outflow in Upper Lynn Canal, think that
dry air will significantly limit snow amounts in Haines and
Skagway, so have not included them in an winter weather
statements. The axis of heaviest snow is expected to fall along
the Coast Mountains from Juneau to Petersburg to Hyder. Juneau
will stay fully within the cold air through the event so expecting
highest snowfall amounts in that area. Petersburg and Wrangell
will change to rain by the afternoon, however heavy snow is
possible for these areas during the morning. Currently expecting
Hyder to remain mainly snow; however confidence is low regarding
the potential for a changeover to rain. Winter Weather Advisories
have been issued for the Icy Strait corridor and
Petersburg/Wrangell for 3 to 6 inches of snow from early Wednesday
morning through Wednesday afternoon. The Winter Storm Watch has
been upgraded to a Warning for Juneau for 4 to 8 inches of snow
through late Wednesday evening. Model soundings for this event
show a pretty stable atmosphere through the column, so any heavy
snowfall rates will be due to upslope rather than storm dynamics.
As the system weakens and departs the region on Thursday,
soundings indicate low level moisture will remain in place across
much of the Panhandle. A weak northern stream upper level system
passes by during this time which may help produce flurries and
snow showers. Put flurries and a slight chance for snow showers
along the Coast Mountains and through Icy Strait corridor through
Thursday evening. There is a chance for freezing drizzle as well
as the DGZ will not be saturated and the moisture remains around
the boundary layer. Although air may be cold enough for some
snowflake development. Little to no accumulations from this weak
system.
Little to no wind issues to mention in the short term. Strong
outflow winds Tuesday evening will gradually diminish Wednesday
morning. The system approaching tomorrow is very weak as the front
pushing in has winds around small craft levels for the Outer
Coast and the Southern Inner Channels.
Overall confident is high over the next 48 hours as guidance is in
good agreement with the track of this next storm and snowfall
amounts.
.LONG TERM.../Thursday through Tuesday night/...This extended
range forecast begins with another low off the outer coast and a
front still impacting most of the Panhandle. The low will have
begun weakening already, so winds will not be overly impactful. A
northerly pressure gradient will produce high end small craft
winds over Lynn Canal through Thursday night, however.
Precipitation, in the form of rain south of Berners Bay by
Thursday afternoon, will diminish and provide only a brief break
before the next front arrives from the west Friday or Friday
night. By Saturday morning, all of Southeast Alaska will be under
the precipitation shield from this front. Additionally, based on
the orientation and trajectory of this front, a warmer low level
airmass will move in behind the front. At this time, confidence
is increasing that the rain/snow line will push at least as far
north as the Icy Strait Corridor by Saturday afternoon. North of
there, this could be another fairly heavy snow event. As the cold
front pushes through on Sunday, the rain/snow line will once again
shift south, eventually reach down to the Dixon Entrance.
Therefore, rain showers will transition back to snow showers from
north to south through the second half of the weekend and heading
into the next work week. -Fritsch
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory from 3 AM to 3 PM AKST Wednesday for
AKZ026.
Winter Storm Warning from 3 AM Wednesday to midnight AKST
Wednesday night for AKZ025.
Winter Weather Advisory from 3 AM to 9 PM AKST Wednesday for
AKZ020>022.
Strong Wind until 6 PM AKST this evening for AKZ019.
Wind Chill Advisory until 6 AM AKST Wednesday for AKZ018.
MARINE...Heavy Freezing Spray Warning for PKZ012.
Storm Warning for PKZ012.
Gale Warning for PKZ013-031.
Small Craft Advisory for PKZ021-022-032>034-036-041>043-051-052.
&&
CM/Fritsch
Visit us at http://www.weather.gov/Juneau1 winter storm. Local standard time, as filed.
A trained spotter in downtown Juneau reported 7 inches of new snow at 8:30 am on February 3rd.
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: 945599.