Winter Storm — Bristol Bay, Alaska

2022-12-24 · Bristol Bay, Alaska

Event narrative

A band of snow developed across the Alaska Peninsula and the Bristol Bay region on the morning of December 24. Several surface observing stations recorded sustained winds of 20 to 30 knots (23 to 35 mph) and visibility at or below 1/2 mile with blowing snow for several hours from Pilot Point to King Salmon along the Alaska Peninsula and from the Dillingham area north to Koliganek in the Bristol Bay region. The worst conditions were seen at locations along the coast, with a brief period of blizzard-like conditions observed by the Clarks Point AWOS during the afternoon. By early evening on December 24, winds diminished, resulting in improved conditions area-wide, though light snow would continue into the overnight hours.

Wider weather episode

A strong upper-level trough originating in the Arctic dove southwestward across Southcentral Alaska on the evening of December 22 through December 23, bringing a reinforcing shot of cold, dense Arctic air into an already cold environment. This combined with a pre-existing strong pressure gradient between strong surface high pressure in Interior Alaska and low pressure over the Gulf of Alaska to produce strong winds through gaps and passes across southern mainland Alaska. Blizzard conditions were seen in the Matanuska Valley, where 65 to 83 mph winds lofted snow and reduced visibility. Winds knocked out power to 7000 residents in the Matanuska Valley and the Anchorage Bowl. Blowing and drifting snow, as well as wind chills as low as 55 degrees below zero were also observed in other portions of Southcentral Alaska.

The trough closed off into a low pressure system aloft late on December 23 as it began to track westward across Southwest Alaska and into the Eastern Bering Sea, allowing conditions to gradually improve over Southcentral Alaska. The upper level low began to interact with a weak surface low crossing the Alaska Peninsula into Bristol Bay on December 24, dropping snow in both regions. Combined with gusty winds, blowing snow affected portions of Bristol Bay and the Pribilof Islands on the evening of December 24 into the morning of December 25 as the system continued into the eastern Bering Sea. Active weather diminished as the low tracked further west into the Bering Sea over the following days.

Source: NOAA Storm Events Database, event_id 1097623. Narrative written by the NWS forecast office that issued the report.