by Kyle Dittmer, CRITFC meteorologist/hydrologist
Rising rivers due to snowmelt is one of many cues that the Creator tells us that spring is here. The normal pattern of rising spring river levels is a cue to salmon smolts to move downriver as fast as possible which helps ensure a safer passage route out to the ocean.
This winter had a La Niña event in the tropical Pacific Ocean, which tends to deliver cool, wetter winters to the Pacific Northwest. January and April were unexpectedly very dry.
Current snow-lines are at 4,500 feet. The mountain snowpacks reached their peak of the season in early April. Temperatures are warming up to start the rapid mountain snowmelt process.
The latest NOAA/National Weather Service forecast suggests that tributary rivers are rising now. The mainstem Columbia River will peak by May 14 (three weeks earlier than historic norms) and slowly recede. Tribal fishers, please be aware of the danger of fast-moving water during these seasonal peaks and take appropriate safety precautions.