31 December 2020
We've been tracking freeze-up progress and timing with real-time cameras throughout the state this season. The Colville River froze first on 25-Oct, followed by a mid-November cold snap that formed complete ice cover in camera views on the Yukon R at Galena and Kantishna near Nenana (20-Nov), Tanana R near Fairbanks (21-Nov), and Innoko R near Shageluk (22-Nov). The Kuskokwim River at Napasiak froze over completely around 1-Dec.
Two new river locations however still had open-water showing in camera views into the new year! The Copper River still was mostly open likely due to its input from the Tazlina R upstream of the camera view. The lower Yukon River view at Paimute (between Holy Cross and Russian Mission) had a large, but gradually shrinking hole in its main channel near a steep bedrock outcrop. We don't know if these open-water zones are unusual this late into the winter or not, but are interested in tracking their progress. We're also starting to get more point observations of persistent open-water zones on our Ice Photo Observation portal and social media. These are adding to a growing body of knowledge about these intriguing and potentially hazardous features in otherwise safe and continuous river ice cover in Alaska.
See this years (and eventually next) freeze-up sequence videos here: