High Wind in Lower Matanuska Valley, Alaska

Winds became gusty in the late morning hours, gusting to over 50 mph by noon. A peak wind gust of 61 mph was reported by the Palmer Airport ASOS (PAAQ) at 2:53 PM AKDT on August 28th. Winds remained gusty until the evening hours. The Alaska State Fair announced closure of some rides on Aug 28 due to high winds, with some performances also being canceled or relocated. Matanuska Electric reported power outages in various locations including Palmer and Wasilla on August 28th.

An series of upper level shortwave troughs lifted northeast from the Northern Pacific. One of these waves moved over the Alaska Peninsula and continued toward Southcentral Alaska. The shortwave's associated surface low developed over Bristol Bay. A strong north-south oriented jet streak helped strengthen this wave. The short wave, combined with a strong ridge over Canada, tightened pressure gradients, triggering strong gap winds across Southcentral Alaska. Furthermore, a capping inversion arose due to warm air advection from southerly flow. This inversion trapped strong winds at lower levels and further enhanced gap winds. A strong Turnagain wind developed on August 28th, which affected the Anchorage Hillside. The Anchorage Bowl saw gusty winds arrive later as the Turnagain Arm bended into the city. The Matanuska Valley saw strong southeasterly Knik winds due to the aforementioned conditions and coastal ridging. Due to this event occurring early in the season, foliage of trees was still full and thus, more vulnerable to strong winds. Downed trees and multiple power outages were reported across Anchorage and the Matanuska Valley.