Ice and Fire

Extensive breakup-related flooding continues for certain unfortunate locations, including Buckland in the northwest, and along a lengthy portion of the Yukon between Ruby and Tanana.  In the words of the river forecast center, it's a "very dynamic" breakup, with ice being displaced only reluctantly by pressure from backed-up river flows.

Photos from the NWS in the past few days:

Spring breakup continues across the Yukon River. Our team flew from Stevens Village down past Tanana on Tuesday. There remains a 120 mile long run of ice moving down the Yukon. Pictured here is a part of that run moving past the bridge on the Dalton Highway. #akwx #riverwatch pic.twitter.com/6LxzZGOB4y

— NWS APRFC (@NWSAPRFC) May 17, 2023

We are saddened to see the damages from ice jam flooding in Buckland, and our thoughts go out to the community during this significant flooding event. Here are some photos taken by our River Watch team on Thursday. The threat of further flooding continues for Buckland. pic.twitter.com/HOacQviDkr

— NWS Fairbanks (@NWSFairbanks) May 19, 2023

The jam is causing extensive flooding along the Yukon River for nearly 90 mi upriver from the front of the jam. The Kokrines Bible Camp is in the flooded area and some flooding can be seen in these photos. Tanana is experiencing minor flooding.

📸 Photos: https://t.co/bsq7GOZGme https://t.co/NCTqVtnlSA pic.twitter.com/JBHDCHLh67

— NWS Fairbanks (@NWSFairbanks) May 21, 2023

 

Ned Rozell's latest dispatch recounts the dramatic breakup in Eagle last weekend:

https://www.adn.com/alaska-news/science/2023/05/19/when-river-breakup-came-to-eagle/

But while the weather has remained chilly in western Alaska - indeed there was a bit of accumulating snow in Bethel on Tuesday and Wednesday - things are heating up in eastern and southeastern Alaska.  Sitka rose to a remarkable 82°F on Thursday, and Haines reached 80°F, both the earliest on record for such warmth.

Also very remarkable was Fairbanks' daily minimum temperature of 60°F yesterday.  (The overnight low Saturday morning was actually 61°F, but it then reached 60°F by midnight Saturday evening.)  Only one other year has had a low temperature of 60°F in May, and that was on the 25th (in 1960).  Some years don't see a single night that warm over the whole summer, most recently in 2020.  And prior to the mid-1960s it was an unusual occurrence in any year.

It's also been very dry recently in Fairbanks, with only 0.08" of precipitation since mid-April, and zero measurable precipitation so far this month.  If warm and dry weather persist into next month, then wildfire risk will rise quickly.  Western Canada is already having an extremely active and early fire season, with fire acreage already exceeding 5 million acres nationwide.  Of course Canada is a very big place, but for reference that's already on par with Alaska's largest fire seasons on record (2004 holds the record, at 6.6 million acres).

Interestingly, the two coldest Aprils of the last 30 years in Fairbanks were also fairly active fire seasons for Alaska: 2013 (1.3 million acres burned), and 2002 (2.2 million acres).  The modern average (median) is about 600,000 acres or so.

The emerging El Niño in the tropical Pacific is definitely a risk factor for increased fire acreage this summer.  Here's a chart I've shown before, updated to include last year:

Last year was actually a surprise from this perspective, because La Niña was still very much entrenched in the tropical Pacific, and yet Alaska's fire acreage was much above normal.  I'll have more to say on this in a subsequent post.