A negatively-tilted trough lifted across Southcentral Alaska between December 7th and 8th. The accompanying front produced a band of moderate to heavy snow which pushed north up the Kenai Peninsula, reaching Anchorage on the evening of Dec 7.
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 AFC wrote it up.
A negatively-tilted trough lifted across Southcentral Alaska between December 7th and 8th. The accompanying front produced a band of moderate to heavy snow which pushed north up the Kenai Peninsula, reaching Anchorage on the evening of Dec 7. The front passed through Anchorage around midnight, leading to a sharp end in precipitation. Several inches of snow fell across much of the rest of Southcentral Alaska with this frontal system as it moved past, ranging from mostly 6 to 13 inches for much of the Kenai Peninsula out to the Matanuska Valley, as well as the Prince William Sound area.
Meanwhile, the parent surface low of the front responsible for the snowfall event across Southcentral moved into the Kuskokwim Delta between December 7th and 8th, producing areas of snow, blowing snow and reduced visibility along the Kuskokwim Delta Coast.
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 Anchorage, AK wrote its last area forecast discussion before the first event at Dec 7, 1:11 PM AKST, 1 hour 46 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
111 PM AKST Thu Dec 7 2023
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...
Radar and satellite imagery continue to show snow and rain for
portions of the Prince William Sound and northern Gulf of Alaska
associated with a weakening area of low pressure. With a weakening
low comes a weakening pressure gradient, and therefore subsiding
winds across Thompson Pass. The Blizzard Warning has been allowed to
expire, though some non-trivial winds with some light additional
snowfall may continue to bring occasional reduced visibility to that
area of the Richardson Highway through the remainder of the morning.
Attention turns towards a strong upper-level trough and associated
cold front that'll move through southcentral Alaska today. As of
430am, satellite imagery currently shows the trough / cold front
pushing through the AK Peninsula and encroaching on Kodiak Island.
Steep low/mid-level lapse rates owing to the cold air (~-15C at
850mb) will produce rather vigorous snow shower activity along the
frontal interface as this front sweeps through. Snow all the way
down to sea level will begin in Kodiak (mainly the western side) and
then spread quickly into the Kenai Peninsula before sunrise, and
north into Anchorage and the Mat-Su in the afternoon to evening
hours.
This cold front may take on properties of a snow squall at times
with snow rates exceeding an inch per hour as it sweeps through, as
well as the potential for gusty winds. Low-density ("fluffy") snow
combined with gusty winds will result in the potential for
significantly reduced visibility. The front is expected to push
through rather quickly, so the heaviest snow should only last an
hour or two at most in most areas. As the front sweeps through,
models indicate deep pressure falls at the surface and surface
cyclogenesis at what becomes the effective triple point off the
Kenai Peninsula. As this moves up towards the western Prince
William Sound, higher snow rates and for a bit longer period of
time are looking likely for the Whittier/Portage area.
Models (including ensemble systems) continue to be in remarkable
agreement with liquid equivalent with this system, indicating a
general range of approximately 0.1 to 0.3 over much of southcentral,
with some higher amounts over higher terrain. With the strong lift
and very cold temperatures aloft snow to liquid ratios are expected
to be around 15-20:1, resulting in snow accumulations ranging from 2
to 6 inches throughout many areas, including Anchorage and the Mat-
Su Valley. Model consensus favors a bullseye over the Whittier-
Portage area, with mean ensemble values near 0.6", suggesting snow
totals of 8-12 inches in short order today.
For Friday and Saturday Southcentral will move into a showery regime
as the cold trough moves over Southwest Alaska. A few weak
shortwaves and steeper lapse rates will likely generate bands of
showers, though the location and intensity will be hard to dial in.
Favored areas will be Valdez and Cordova, where the cold air
streaming over a long fetch of warm water may generate bands of
intense, low density snow.
-Brown
SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Today
through Saturday)...
Longwave troughing with a series of embedded shortwaves moves
across the Bering Sea and Southwest Alaska over the next few days.
As a whole, the system that is now near the Seward Peninsula is
weakening. Winds across much of the Bering have diminished to
small craft, with some gales along the northeastern portions. Snow
continues across much of Southwest Alaska as well as the Eastern
Aleutians and southern Alaska Peninsula today. Chances across
Southwest diminish into the afternoon as the initial front moves
across the Kilbuck Mountains. The southern AKPen will continue to
see periods of snow showers behind the front, accompanied by a
colder air mass covering almost all of the Bering and Southwest
Alaska. Temperature across the Southwest Mainland are expected to
drop into the teens and single digits by Friday and approach near
zero by Saturday. Overnight temperatures for inland areas will
reach at or below zero Friday night and Saturday night, while
areas along the coast will drop into the single digits.
LONG TERM FORECAST (Days 4 through 7)...Sunday through Wednesday...
High pressure over the Russian Far East and The Western Canadian
Provinces bracket the long wave trough over Central Alaska through
Wednesday. Trough axis shifts Eastward, moving a pocket low
towards the Gulf by the end of the forecast period. Forecast
confidence starts mixed, due to transient shortwaves over the
Eastern Bering and low centers moving along the South coasts.
However, model confidence improves by midweek. With the trough
through the Central Mainland as a well developed North Pacific low
moves along South of the Alaska Peninsula into the Gulf of Alaska
for Monday and Tuesday. Considerable moisture will be pumped into
most of Southcentral Alaska, with heavier rain or mixed rain/snow
from the Kenai Peninsula along the coastal zones to the Canadian
border. Inland areas into the foothills of the Alaska Range remain
cold enough for snow.
For the Alaska Peninsula and the Aleutians, snow changes over to
mixed rain and snow as a North Pacific low presses closer to the
Chain. Near gale force winds increase to areas of gales over the
Eastern Bering through Wednesday. The Central Aleutians open with
areas of gales associated with the North Pacific low for Sunday.
As the low moves Eastward, gale force winds straddle the Alaska
Peninsula, and spread into the Gulf Monday through Wednesday. A
gale force barrier jet forms over the Northern Gulf late Monday,
diminishing through Wednesday.
Kutz
AVIATION...
PANC...IFR/LIFR ceilings and visibility will improve to MVFR/IFR
as low-level northeasterly winds begin to increase ahead of a
strong cold front that will move through Anchorage later this
evening. However, light to moderate snow, with some periods of
heavy snow, is likely this afternoon/evening, particularly in the
02-06z timeframe. Snow rates at or in excess of 1 inch per hour
may occur for an hour or two during that window, with visibility
briefly to a half mile or less. Total snow accumulation of 1 to 4
inches is most likely. The snow will be of low-density ("fluffy"),
likely contributing to some visibility issues that will be
enhanced by gusty winds. Conditions will greatly improve by later
tonight in the post-front regime. Some lingering flurries are
possible, but additional accumulation is unlikely.
Continued with LLWS for a brief period this afternoon as SE winds
pick up above a lighter northeast wind. This should be brief as
winds will increase out of the SW as the front pushes through.
&&SPECIAL WEATHER STATEMENT National Weather Service ANCHORAGE AK 907 AM AKST Thu Dec 7 2023 AKZ102-072130- Anchorage- Including the cities of Anchorage, Eagle River, Indian, and Eklutna 907 AM AKST Thu Dec 7 2023 ...LOCALIZED DENSE FOG THIS MORNING ALONG THE GLENN HIGHWAY AND WEST ANCHORAGE... Localized areas of dense fog have developed across mainly northern and western parts of Anchorage this morning. Visibility as low as a quarter mile will be possible until fog lifts, mainly on the west side of town and along portions of the Glenn Highway at times. Slow down and allow extra time to reach your destination this morning due to reduced visibility in patches of dense fog.
Preliminary Local Storm Report
National Weather Service Anchorage AK
1226 PM AKST Thu Dec 7 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0300 PM Snow Wasilla 61.58N 149.37W
12/06/2023 M3.0 inch Matanuska-Susitna AK Public
A member of the public measured 3 inches of
snow. Storm total. Delayed report.
0534 PM Snow Butte 61.53N 149.01W
12/06/2023 M3.3 inch Matanuska-Susitna AK Trained Spotter
A trained spotter measured 3.3 inches of
snow. Storm total. Delayed report.
0541 PM Snow Wasilla 61.56N 149.33W
12/06/2023 M3.0 inch Matanuska-Susitna AK Trained Spotter
A trained spotter measured 3 inches of snow.
Storm total. Snow fell between 8 pm Dec 5
and 3 pm Dec 6. Delayed report.
0500 PM Snow Eagle River/Hiland Rd 61.23N 149.44W
12/06/2023 M7.6 inch Anchorage AK NWS Employee
An NWS employee measured 7.6 inches of snow.
Storm total. Snow began 10 pm Dec 5. Delayed
report.
&&5 winter weather, 1 avalanche. Local standard time, as filed.
Snowfall amounts during an intense round of snow that pushed up the Kenai Peninsula into Anchorage late December 7th to the morning of December 8th ranged from 4 to 10 inches across town. The highest storm total snowfall of 10 inches was reported on the Anchorage Hillside at around 7 AM AKST 12/8.
An RWIS/DOT observation site in Portage reported 2 to 3 hours of moderate to heavy snow with visibility under 1 mile between 9 PM AKST 12/7 and 12 AM ASKST 12/8 with winds gusting from the west between 20 and 35 mph.
The Matanuska Valley saw the heaviest snow on the evening of Dec 7 until shortly after midnight with a frontal passage. 3-6 inches of snow was observed, with the highest total of 6 inches reported from a trained spotter in Sutton at 7 AM AKST December 8th.
The Grouse Creek Divide SNOTEL recorded an increase in snow depth of 10.7 inches between the afternoon of 12/7 and about 11 PM of the same evening. Heavy snow and blowing snow was also recorded intermittently in Seward and Whittier during this timeframe.
The Mekoryuk AWOS recorded several hours of snow and blowing snow between 1 PM and 10 PM AKST 12/7 with visibility as low as 1/4 mile and sustained winds between 25 and 35 mph.
A COOP observer reported 13 inches of new snowfall in Valdez from heavy snow moving through between the late evening of 12/7 and the morning of 12/8.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2023Every state in 2023This day in weather historyWarnings in Alaska, December 2023
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: 1147366, 1147369, 1147370, 1147373, 1147377, 1147376.