BOZEMAN – Major flooding is impacting multiple river systems across the state. Locally, the Gallatin River and the Yellowstone River are the two river systems that have flood warnings in effect for several days.
The National Weather Service has a FLOOD WARNING to the Gallatin River near Big Sky downstream by Logan. Minor to moderate flooding is likely over the next 2 days, with water levels expected to drop below flood stage by the end of the week.
The Gallatin River in Logan could reach 10.5′ by Tuesday and that will put that area in the ‘moderate’ flood range. The same between Big Sky and Gallatin Gateway, the river there could reach 7.2′ by Tuesday and that’s also in the ‘moderate’ flood range.
The Yellowstone River from Yellowstone National Park to Billings is under a FLOOD WARNING until Wednesday evening. This river system has experienced historically high water levels.
At Corwin Springs, the river peaked at 13.69′ on Monday morning, surpassing the old all-time high of 11.5′. In Livingston, the Yellowstone River peaked at 10.84′ Monday morning, surpassing the old record of 10.7′.
The good news here is that predicted river levels are expected to drop sharply by Wednesday and fall below flood stage by the middle of the week.
The weather forecast calls for just a little more precipitation through Tuesday for southwestern Montana and there’s a good chance of snow in the mountains Monday night through Tuesday above 5,000 feet. Snow accumulations will be quite varied with an inch or two around 5,000 feet and perhaps 6 inches or more above 8,000 feet.
While the current storm is slowly rolling through the Montana High Line with more heavy rain along the Montana and Canada border with the southern end of the storm, the humidity isn’t as impressive. This low pressure system will continue to push towards Canada and will exit the region by Thursday.
The replacement for this storm will be a rapid warming with high pressure moving through the state and temperatures could climb into the 80s and some lower 90s by Friday.