Spring 2018 River Flow Forecast
The spring snowmelt (or freshet) causes rising high water levels in the Columbia River and its tributaries each year. This condition helps get salmon smolts downriver quickly, but also makes it dangerous for fishers. CRITFC monitors river conditions and forecasts during the year. We inform fishers of the predicted timing and nature of the freshet to help improve their river safety. River flow is increasing now and will reach its seasonal peak this week (flow will be fastest during that time) then recede through May and early June. The peak is 26-days earlier than normal this year and likely due to increasing climate change impacts.
The NOAA-National Weather Service May 8 river spring-summer forecast for the Columbia River at The Dalles is at 126% of normal. This winter’s La Niña event enhanced mountain snowfalls and gave colder than normal temperatures, which greatly increases our spring-summer water supply. This means that the freshet will be above normal this spring, giving favorable conditions for juvenile salmon migrating out to the ocean and for returning adults. Ocean conditions are expected to remain favorable in 2018 for salmon survival.
Current Columbia basin snowpack accumulation: Upper Columbia and Washington Cascades 90 – 150% of normal, Oregon Cascades and lower Snake 50 – 110% of normal, Clearwater 110 – 150% of normal, southern Idaho 25 – 110% of normal. Current snow levels are about 4700 feet.