RiverWatch officials flew what could be their last breakup monitoring flight on the Yukon-Kuskokwim Delta this week.
That’s in part because breakup on the Yukon River this year is looking like what hydrometeorologist Kyle Van Peursem calls a “non-event.”
“This year, even our pilot remarked how different it looked from last year. The water is [the] lowest that folks have seen in a while,” Van Peursem said on May 14.
Van Peursem is part of a team from the National Weather Service, Alaska-Pacific River Forecast Center, and State Emergency Operations Center that monitors breakup on rivers throughout the state.
Van Peursem and the RiverWatch team just wrapped up two weeks of daily flights over the lower Kuskokwim River, where communities are now starting to take stock of floodwater damage after grappling with more than a week of flooding and high water. Strong ice across the river caused jams that backed up water far into the tundra and kept communities submerged for days.
That’s not the case on the Yukon, Van Peursem said. While some Yukon River communities are seeing water rise as breakup proceeds downriver, there weren’t areas of serious concern as of May 14. From as far upstream as RiverWatch officials could see from their aerial vantage point at Russian Mission, all the way down to Marshall, there’s no truly intact river ice on the Yukon, he said.
“It's very low impact right now. Tons of sand bars are sticking out, so the low water is very visible below bank,” Van Peursem said.
As of the morning of May 14, the Yukon River breakup front sat just below Marshall, while Van Peursem said that ice around Pilot Station was looking ready to break up, with “tons of cracks and pressure ridges.”
Below Pilot Station, there’s more intact ice as the river moves to the coast.
But Van Peursem also said that river ice on the lower Yukon is thinner than average. One observer measured ice 2 feet thick, in an area that is generally around 4 feet thick this time of year. That’ll help it break up easier. Van Peursem said that there’s not really solid ice upstream that could come down and cause flooding like last year’sdisastrous high water on the Yukon River.
Van Peursem said that the smooth conditions on the Yukon may spell the end of active RiverWatch reconnaissance flights. The team will continue monitoring the situation through community phone calls and satellite imagery, and jump into action if water starts rising. But that’s not likely.
“If we get reports that the water's starting to go up or it’s jamming then we can scramble and start doing reconnaissance, but right now it's looking like it probably won't happen,” Van Peursem said. “We’ve still got a week or so, is what they're saying until it reaches the mouth. So by that time the ice will be pretty degraded.”
Throughout the coming week, cold weather is forecast to persist on the lower Yukon, potentially slowing breakup for areas with intact river ice. An Emmonak community member reported on May 14 that it’s freezing near the coast, and that community members are still traveling by sno-go.
KYUK’s Evan Erickson contributed to this reporting.
