MISSOULA – Although it’s been darn cold with unseasonably sharp overnight temperatures it looks like we might skate through this last cold spell without the problem of ice jams on area rivers.
When temperatures plunged below zero again to start last week, there were renewed concerns we could see ice jams forming on areas rivers and streams.
While the afternoons were warmer the past few days, overnight lows were still flirting with the single digits. But with temperatures trending warmer this coming week the risk of ice jams is looking less likely.
“We’ve got quite a few freeze-up ice jams in different places. I mean there’s one right here, right now, in East Missoula, that’s clogging up the river. But the rivers making its way around that and channeling through just fine,” National Weather Service Hydrologist Ray Nickless explained.
Places like the Clark Fork above Missoula — and many of the streams in the Bitterroot — are still choked with snow and ice.
But if you look closer, there are signs of movement and that’s a good thing because it shows the water is able to find a way to “channel around” obstructions.
Although Nickless says there’s not much chance of a major ice jam now, they will be watching closely for smaller jams to form as this winter ice starts to break up.
“The thing we worry about a little bit this time of the year is what we call ‘break up’ ice jams,” Nickless said.
“So if we get too much water flowing into the streams from snowmelt and rainfall runoff, that can create a quick ‘break up’ ice jam. So, we’ll just keep an eye on that and getting into that type of environment.”
Nickless says forecasters will be continuing to watch the smaller streams, which could start causing problems quickly if we get a sudden warm up, especially if we also receive rain.
“There’s quite a bit of ice in the smaller streams and some of the rivers here in Western Montana. But the good thing is, with the temperatures we’re seeing now, we’re just kind of seeing the channeling of the water through the ice and under the ice,” Nickless said.
“So as long as we don’t get into some big warm up with a bunch of rain causing a lot of runoff I think we’ll be okay with the ice that’s in the rivers and streams.”
Nickless is advising residents who live along rivers and streams to make sure to keep a wide berth from the disintegrating ice and to watch for any problems that could develop along their shoreline properties as the break up happens.
