*Written by Ryan Niemeyer
Spring has definitely sprung and summer is well on it’s way here. Right now our snowpack looks solid, which is good news for our water resources and our salmon. But many of us remember back to last year when the snowpack was well above average in April across the Upper Columbia, but the heat dome quickly melted the snowpack in June. That rapid melt of the snowpack had a huge impact on the August and September low flows in our. Although we still have several months before we can know for sure how our low flows will be in our streams this summer, at this point in time we are looking pretty good.
First, our Upper Columbia snowpack is at 162%, which is 62% above normal for late May. Last year on the same day of the year we were at 105%, so only 5% above normal. So, we have more snow right now in late May than we did last year. Furthermore – at many sites at the 4,000 – 5,000 feet elevation range (e.g. Stevens Pass), the snow started to rapidly decline in mid-May and was gone by early June. Our 10-day forecast is mild, so our snowpack is likely to slowly melt and not experience a rapid decline going into June.
Second, the NOAA temperature outlook for this summer has our region at an equal chance of having above or below average temperature. This is good. However the seasonal precipitation outlook is for below average summer precipitation. So we could experience a dry summer that depresses summer low flows.
Only time will tell how our low flows fare this summer. But heading into summer, we are off to a good start.