High Wind — Anchorage, Alaska

2024-12-09 to 2024-12-10 · Anchorage, Alaska

Event narrative

A CWOP weather station on the Anchorage Hillside reported a maximum wind gust of 81 mph at 3:17 PM AKST Dec 9th. Other observation sites in the sane area reported wind gusts between 60 to 75 mph at around the same time. Wind gusts remained elevated between 60 and 70 mph in the Hillside over the course of the day and into Tuesday Dec 10th until around 8:00 AM. The lower elevations had wind gusts between 45 to 55 mph until around 7:00 PM Monday. There were reports on social media of siding being ripped off a home in Ft. Richardson as well as a broken window and a minor injury. A large tree snapped and fell on a power line in the Spenard area sometime on Monday, leaving 1800 customers without power in the Chugach Electric Service area and 1300 without power in the Matanuska Electric service area by 9:30 PM that same day.

Wider weather episode

A stalled trough over Prince William Sound interacted with a strong occluded front and upper-level shortwave in the Western Gulf. This had the effect of tightening pressure gradients across Southcentral Alaska, which ultimately resulted in widespread gales and localized storm-force gusts over marine areas. Wind gusts in the Anchorage Hillside reached 55 to 60 mph on Sunday Dec 8th in the afternoon. A north-south pressure gradient was expected in the overnight hours of Monday which would reduce the wind speeds in the Anchorage, Portage, and Whittier regions but then realign as the front advanced, raising wind speeds in those areas to even higher heights.

Wind speeds were expected to gust to 55 to 70 mph on the Anchorage Hillside and 45 to 60 mph in Whittier and Portage. However, Portage gusted to 85 mph Monday Dec 9th in the morning hours, exceeding forecasts. On the Anchorage Hillside, winds were light until the front pushed through, which quickly rose and peaked at 81 mph on the upper Hillside and reaching 45 to 55 mph in lower elevations of the city. These strong gusts damaged structures and trees in the Anchorage and Matanuska Valley regions. Power outages were reported due to trees falling on powerlines.

Source: NOAA Storm Events Database, event_id 1227373. Narrative written by the NWS forecast office that issued the report.