No snow in the Valley (until yesterday!), while high elevations may be tracking for a record year.

The atmospheric river that parked itself over the state last week dumped an historic amount of moisture around Washington state. Meteorologists estimated over 5 trillion gallons of rain fell over the state last week.  A drenching across the Methow valley (5.11 inches of rain in Mazama from, Dec. 9–11) stripped it of most of its snow and raised river and creeks to near or above flood stage, especially in the upper valley. Mudslides covered highway 20 and flooding near Mazama closed the highway and surrounded homes.

Anomaly or more of a new norm?

A key chapter of the Methow Valley Climate Action Plan, outlines the predicted impacts of climate change on the Methow Valley based on the modeling done by Dr. Amy Snover and the University of Washington Climate Impacts Group. Expected shifts in our climate include wetter, warmer winters, higher winter stream flows and earlier seasonal flooding. An analysis of atmospheric rivers since 1980 has found that storms are wetter and have already increased in area by 6-9% and frequency by 2-6%. A warmer atmosphere carries more moisture. While we shouldn’t yet count on brown, bare hills in December, it is likely to become a more frequent occurrence.

So far, there’s a snowy silver lining

There is still a lot of snow in the mountains for this time of year. The Methow Basin snow water equivalent (the amount of water held in the snowpack) was 152% of median as of December 19 (averaged over 4 snotel sites at low and high elevations). As of today (December 19) since record keeping began in 2000, Hart’s Pass has not had this much snow at this time of year. Over 8 feet (99 inches) has stacked up in the snowpack (5+ feet has fallen in the last two weeks!) We don’t know how the rest of winter will play out but thus far our giant snow reservoir that impacts our summer rivers flows looks to be in good shape. This pattern, with plenty of snow at higher elevation and little snow at lower elevation could become more common in the coming decades.

Another reason to reduce emissions and prepare for change

Fortunately, we have a sound Methow Valley Climate Action Plan, a living document that can help guide us through the changes and challenges coming our way! You can read more about the climate impacts we should expect in the Methow Valley and the strategies we as a community are taking to prepare. Our program accomplishments outline some of our successes this year.

Photo: Jeff Podmayer