More Rain and Ice

The superlatives continue to be in demand when discussing the impacts of the "atmospheric river" that is affecting interior and southern Alaska.

First, to highlight the extraordinary strength of the winds across the North Slope yesterday, Rick Thoman notes that both the maximum sustained and peak gust wind speeds measured in Utqiaġvik were the highest on record:

In other news from yesterday, an avalanche closed the Parks Highway for about 24 hours near Cantwell:

https://alaskapublic.org/news/alaska-desk/2025-01-24/avalanche-blocks-parks-highway-near-cantwell

Today Fairbanks and Nenana saw another 10-12 hours of rainfall, although very light in Fairbanks, but farther to the west and north (Tanana, Fort Yukon) the temperature dropped enough for snow instead of rain.

To the southwest along the nearly stalled frontal boundary, prolonged freezing rain has been occurring; McGrath seems to have suffered a major ice storm.  A simple animation of photos from the McGrath FAA webcam shows trees and bushes becoming increasingly weighed down by ice today - look closely at the vegetation on the lower left (click to enlarge):

 

Remarkably, the storm total precipitation in McGrath has exceeded 2 inches, and it appears this will be the greatest 2 or 3-day precipitation total on record in the winter months for McGrath; the record 3-day total for December through February is 2.1" in December 1990.  Over in Talkeetna the 72-hour total of 3.38" appears to be second only to a December 1999 event (4.13" in 3 days).

This morning's 500mb chart (see below) shows the same powerful southwesterly flow over southwestern Alaska, and it illustrates clearly the deep southern origin of the warm, moist air.  The ridge anchored over the northeastern Pacific is really the key feature, and it's very reminiscent of events from 10-12 years ago, when the "ridiculously resilient ridge" set up shop in the same region.

https://en.wikipedia.org/wiki/Ridiculously_Resilient_Ridge