Winter Weather — Matanuska Valley, Alaska

2023-11-23 to 2023-11-24 · Matanuska Valley, Alaska

Event narrative

Alaska DOT reported icy roads along the Parks Highway from milepost 29 north. Temperatures were above freezing for the Palmer and Wasilla areas, so as several periods of rain showers moved across the Matanuska Valley on November 22 through 24, the areas that saw freezing rain and icy road conditions were in the Big Lake/Houston area, where temperatures were below freezing at times.

Wider weather episode

After a stretch of very cold temperatures associated with Arctic high pressure, a much warmer and more active pattern took shape across Southcentral and Southwest Alaska as multiple low pressure and frontal systems rotated north around a broad, deep low centered over the Aleutian Islands. The deep southerly flow aloft transported much warmer air north with each system. Colder air was able to hold on at the surface over interior valleys and lower elevations even as warmer air above freezing streamed north and west a few thousand feet above sea level. This resulted in favorable conditions for freezing rain and drizzle, with multiple rounds of freezing rain causing difficult travel conditions between 11/21 and 11/24 before temperatures at ground level finally warmed above freezing for most of the southern Mainland.

Source: NOAA Storm Events Database, event_id 1142724. Narrative written by the NWS forecast office that issued the report.