Winter Weather — Susitna Valley, Alaska

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

Event narrative

Precipitation began as snow on November 22, but as temperatures warmed aloft with persistent southerly flow, freezing rain began to mix in with snow at times on November 23. Reports from the MAWS in Skwentna, as well as the ASOS in Talkeetna, indicated periods of light freezing rain. Freezing rain transitioned over to rain by November 24 as surface temperatures warmed. The Alaska DOT reported icy roads along the entire length of the Parks Highway through the Susitna Valley on the morning of November 24.

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 1142700. Narrative written by the NWS forecast office that issued the report.