Heavy Snow in Northeast Prince William Sound, Alaska

DOT closed the Richardson Highway, including Thompson Pass, around 10:40 am Jan 28, from MP 12-42 due to heavy snow and the potential for avalanche mitigation. Meanwhile, the Valdez Avalanche Center issued an Avalanche Warning for mountains surrounding Valdez and Thompson Pass due to the avalanche danger in place. DOT eventually reported 5 to 10 inches of snow along the Richardson Hwy between MP 12-42.

Other local storm reports include: 28 inches, 30 inches, and 42 inches of snow in and around Valdez. There was also a snow report of 42 inches near Robe Lake in Valdez.

Between January 28th and January 29th, a strong low pressure system organized over the Gulf of Alaska, then moved north towards the Prince William Sound. This low was able to interact favorably with an extremely cold air mass entrenched over the southern Mainland, producing very high snow to liquid water ratios for the duration of the snowfall event across much of Southcentral.

The deep layer of cold air was able to stay mostly in place across the Mat-Su Valleys and Cook Inlet region as moderate to heavy snow moved in near the approaching low. This lead to the extremely unusual combination of surface temperatures between 0 and 5F and heavy snow that lasted for many hours between 1/28 and 1/29. This storm had widespread impacts to travel due to the prolonged nature of moderate to heavy snowfall rates for numerous locations.