Warm moist air aloft was lifted over cold air at the surface over the northern Lynn Canal area on the morning through the evening of 12/5. This resulted in significant, new snowfall ranging 6 to 13 inches over 12 hours.
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.
Warm moist air aloft was lifted over cold air at the surface over the northern Lynn Canal area on the morning through the evening of 12/5. This resulted in significant, new snowfall ranging 6 to 13 inches over 12 hours. The impacts were snow removal for the towns and highway system.
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 Dec 4, 3:14 PM AKST, 12 hours 46 minutes earlier.
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
314 PM AKST Wed Dec 4 2019
.SHORT TERM...Main forecast concerns in the short term deal with
a developing system in the gulf that will impact much of the
northern panhandle Thursday.
An upper shortwave continues to drive shower activity across much
of the central panhandle this afternoon. Low to mid level
circulation currently just off the coast of northern Baranof
Island will push eastward across the panhandle this evening and
continue to weaken overnight. Many locations have been reporting a
mix of rain and snow this afternoon from the Icy Strait corridor
to Petersburg, while Wrangell south has been mostly rain showers.
A few locations may see accumulating snow up to 2 inches including
the Mendenhall Valley in Juneau and Petersburg. The showers are
expected to diminish by early Thursday.
A potentially significant system will approach the NE gulf coast
early Thursday from the SW. A vigorous upper shortwave in the W
gulf will lift across the gulf Thursday morning pulling moisture
from a weak southern stream. At the surface, interaction between
a low in the NW gulf and the low lifting from the SW looks to play
a role in the timing and snowfall Thursday. The lifting low will
likely steal energy from the northern low and pull back slightly
allowing for moisture to move over the NE gulf coast, including
Yakutat. Snow showers are expected early Thursday morning through
the afternoon with amounts of around 4 to 6 inches expected,
before mixing occurs and warms surface temperatures.
Low level SW flow will strengthen through Thursday evening across
the northern panhandle. Forecast profiles sill show strong ascent
within the dendritic growth zone and along with strong synoptic
lifting expect some fairly intense snowfall rates in the upper
Lynn Canal area, including Haines and Skagway. The arctic
boundary looks to remain just south of that area with temperatures
remain at or below freezing through the event. Currently
expecting 4 to 8 inches to fall Thursday, with greatest snowfall
rates late Thursday morning through Thursday evening. Not
expecting much change in the air mass across the Icy Strait
Corridor with temperatures near or slightly above freezing and
southerly winds keeping the boundary well mixed. This will likely
keep precipitation as a rain/snow mix, while valley locations,
including Mendenhall, may see some accumulating snowfall. The
southern panhandle will remain rather dry Thursday with weak low
level offshore flow. Model agreement is better but with showery
conditions expected overall forecast confidence is average at
best.
.LONG TERM...Friday through Wednesday as of 10 PM Tuesday/ Friday
begins with the remnants of dissipating low pressure system
providing a chance of snow over the northern and central inner
channels. However, this will mark the beginning of a slow warming
pattern for southeast Alaska through the early part of next week.
The chance of a frontal passage this weekend still exists but
remains uncertain. It ultimately relies on how the ridging pattern
in place over the Gulf evolves this weekend. Thus a chance of
precipitation remains in the the forecast through the weekend with
increased probability along the northeast Gulf coast.
Unfortunately, forecast confidence is low in the extended as large
ensemble variability still exists and run to run consistency
remains poor; thus, little change was made to inherited forecast.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...Winter Storm Warning from 9 AM to 9 PM AKST Thursday for AKZ018-
019.
Winter Weather Advisory from 3 AM to 3 PM AKST Thursday for
AKZ017.
MARINE...Small Craft Advisory for PKZ012-022-041>043-051-052.
&&
DDH/JB
Visit us at http://www.weather.gov/Juneau3 winter storm. Local standard time, as filed.
Very heavy snow occurred in Yakutat with a total of 8.5 inches in town and 10 inches at the airport. The Weather Service Office noted rates of 3 inches in just over 2 hours.
The Klondike Highway got the most snow, but amounts were highly variable from White Pass to Skagway. New snow amounts ranged from 5.4 inches at Dyea to an estimated 10 inches on the Klondike Highway. Impacts were snow removal and poor driving conditions.
New snow amounts ranged from 5 inches at Haines Customs to 14 inches on the Chilkat Peninsula. One spotter in Haines reported 10 inches in 6 hours. Impacts were snow removal and poor driving conditions.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2019Every state in 2019This day in weather historyWarnings in Alaska, December 2019
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: 867590, 859068, 859067.