A short wave upper trough moved over the Panhandle on the night of 2/22, and the associated front caused heavy snow for the Central Panhandle. Cold air in place closer to the coast mountains will resulted in heavy snow with a high water content.
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.
A short wave upper trough moved over the Panhandle on the night of 2/22, and the associated front caused heavy snow for the Central Panhandle. Cold air in place closer to the coast mountains will resulted in heavy snow with a high water content. Most snow was 10 to 1 or less which made heavy snow removal the main impact.
Temperatures in Juneau warmed up into the mid 30s overnight on 2/22 causing Downtown, Lemon Creek, and the airport to change over to rain (with less then an inch of snow accumulation before that). Snow continued in the mendenhall valley but rates were low enough that only around an inch of accumulation was observed. For Petersburg and Wrnagell temperatures also warmed overnight 2/22 but more snow was observed before the change over especially at Petersburg. wildly varying snow amounts with less then 1 inch at Kake and Wrangell while 5 to 6 inches were observed at 9 mile on the Mitkof highway.
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 22, 2:51 PM AKST, 9 minutes earlier.
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
251 PM AKST Thu Feb 22 2018
.SHORT TERM.../Through Friday night/ Low pressure will move ESE
from the N gulf to the central panhandle by midday Fri. The low
will weaken and continue SE Fri night. Another low will move E
into the NW gulf Fri night. This will be a continuation of the
active pattern that has been going on since last weekend. Ended up
making only minor changes to the forecast as it was in pretty
good shape overall, although did tweak POPs and winds a bit based
on trends.
Still keeping the WSW for heavy snow for zones 25 and 26. Added in
a WWA for zone 18. Still looks like a wet snow will fall in the
Juneau and Petersburg areas with 4 to 8 inches likely by 18z Fri.
Still some concerns about low level temps in these areas, but
current expectations are that the high precip rates/snowmelt
cooling will overcome the slight warm advection in the lower
levels to keep precip mainly as snow in the warning area. The WWA
for zone 18 will be mainly for higher elevations, with 3 to 6
inches likely tonight. Still expecting mainly rain along the outer
coast, with rain and snow over the S inner channels. As low
sweeps SE through the area Fri, precip should diminish from the NW
during the day.
Some colder air will move in late Fri and Fri night as flow
becomes northerly between systems. Should see decent breaks in the
clouds develop Fri evening, but clouds will increase again later
Fri night ahead of the next low moving into the gulf. Some precip
could reach the outer coast by daybreak Sat.
.LONG TERM.../Saturday through Thursday/ A much more active
pattern can definitely be expected for SE Alaska. For the early
part of the long term on Saturday, we'll start off with a
developing shortwave out of mainland Alaska that will strengthen
over the central gulf and impact the panhandle. Overall, our
confidence has increased regarding this feature, and deterministic
models have come into better agreement. Model 500 mb vorticity
and winds indicate additional strengthening from increasing
vorticity and jet dynamics. It appears to take a similar track as
some of our previous lows, and if we go off precedence, the
precipitation type with this system will most likely remain as
snow, and model 925 mb temperatures confirm our suspicions. The
more difficult aspect with this shortwave will be QPF or how much
precipitation we can expect. Due to the origin of this shortwave,
moisture may initially be lacking, but the marine environment may
alleviate this, as there appear to be relatively strong west,
southwesterlies aloft to advect in additional moisture.
On Sunday, model analysis continues to show this low weakening as
it tracks southeast along the panhandle and a weak ridge of high
pressure quickly building in behind Sunday night into Monday.
Another shortwave then appears develop Monday, again over the
central gulf, before possibly impacting the panhandle Monday
night. However, there is quite a bit of disagreement among the
deterministic models regarding surface features and timing. Seeing
this, we tended to gravitate towards WPC guidance Tuesday onward
to account for this uncertainty.
The main changes we made to the long term forecast consisted of
increasing chances for precipitation on Saturday and continuing
into Sunday. In addition, we increased winds over the gulf and
some of the inner channels Saturday night into Sunday as that
developing low mentioned previously strengthens and the pressure
gradient tightens between it and a high pressure over British
Columbia, Canada. We tended to gravitate towards the NAM for the
12Z Saturday to 12Z Sunday period, as models were in pretty good
agreement at this point. After this period, we mainly chose to use
WPC guidance and NBM analysis.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...Winter Storm Warning until 9 AM AKST Friday for AKZ025-026.
Winter Weather Advisory until 5 AM AKST Friday for AKZ018.
MARINE...Gale Warning for PKZ012-013-041>043-051-052.
Small Craft Advisory for PKZ021-022-031>036.
Small Craft Advisory due to Seas for PKZ053.
&&
RWT/Voveris
Visit us at http://www.weather.gov/Juneau1 winter storm. Local standard time, as filed.
Mitkof Highway got 5-6 inches of new snow overnight on 2/22. Impact was heavy wet snow removal.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2018Every state in 2018This day in weather historyWarnings in Alaska, February 2018
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: 738518.