Winter Weather — Anchorage, Alaska

2023-11-22 to 2023-11-24 · Anchorage, Alaska

Event narrative

A series of upper-level troughs tracking northward across Southcentral Alaska led to several periods of rain/freezing rain within the Anchorage Bowl from November 22 through November 24. The first report of freezing rain came in from an NWS employee along the Glenn Highway on the evening of November 22. The next day, a trough tracking north across Southcentral Alaska around midday produced a more substantial band of rain showers, which passed through the Anchorage Bowl around noon. Various ASOS/AWOS reports of freezing rain/unknown precipitation came from Lake Hood, Merrill Field, Elmendorf, Fort Richardson, and Birchwood. Temperatures quickly warmed above freezing, turning precipitation to meteorological rain.

Temperatures fell back below freezing on the evening of November 23. A second band of rain showers crossed the Anchorage Bowl around 9 pm, producing a glaze of ice. Temperatures broadly warmed above freezing overnight, though isolated spots may have seen freezing rain on the morning of Nov 24 with another band of rain. Temperatures warmed further as it passed through and winds shifted out of the southeast.

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 1142707. Narrative written by the NWS forecast office that issued the report.