Summer 2015: The Northwest's Global Warming Stress Test

By the end of the summer, we will know whether the Pacific Northwest is ready to deal with global warming.   And if not, what we need to do to prepare.  A virtual climate stress test.

As I have noted in a previous blog, our winter and spring have brought weather conditions that are stunningly close to those expected to be normal by the end of the century.

In short, this winter we were much warmer than normal, with near normal precipitation and far below normal snowpack.

For example, during our core winter months, temperature over our region was roughly 2-6F warmer than normal, and over the past year we were 2-4F above normal.

In contrast, our precipitation over the water year (since October 1) has been near normal (yellow/green colors, see graphic)

And our snowpack has been abysmal, with the Washington Cascades currently at around 20% of normal, the Olympics at 1% of normal, and only the mountains of NE Washington as high as 50%.

According to regional climate simulations run at the University of Washington and the analyses of the UW Climate Impacts Group, these conditions are close to what is expected around 2070.

So the central question is:   is our society ready for 2070 conditions, today in 2015?

We are about to experience a climate change stress test.  How will we manage?

With so little snowpack, will there be enough water for personal use and agriculture?
Will there be major destructive wildfires?
Will salmon and other wildlife be hurt by low summer streamflow?

By the end of the summer we will know....

The latest model forecasts suggest we not only start with 2070 spring conditions, but this summer will be warmer than normal.  For example, the latest NOAA Climate Forecast System model forecasts for June-July-August are for surface air temperatures of 1-2 C (2-4 F) above normal.

Adaptation measures

Our local, state, and Federal officials are pulling out the stops to prepare us for 2070 conditions.  As I mentioned in an earlier blog, Seattle Public Utility managers very wisely brought the levels of the Tolt and Chester Morse reservoirs way, way UP during the winter rains, thus making up for the lost snowpack in late spring and early summer (the red line is this year's reservoir storage, green is last year, and blue is average).  Even without much snowpack, the city has enough water to get through the summer.  That is resilience.

The biggest water fears are in the Yakima Basin, where there is insufficient storage to get through an entire summer without snow melt.   But there ,the U.S. Bureau of Reclamation did something daring: they decided early in the winter not to worry about potential flood risk and begin filling the reservoirs much earlier than ever before.   A week ago, they essentially had them all at 100%, something never done this early in the season.  

The graphic below shows the total storage of the 5 major Yakima reservoirs (blue line) compared to last year (green) and an average year (red).   They topped off the reservoirs near the max MONTHS before normal.  Daring and smart.  There will still be water shortages on the Yakima, but nothing compared to what would have happened if the Bureau of Reclamation didn't act so proactively.

The Columbia River flows will be low, but not near any records because the snowpack in BC was much higher and the Columbia drains off of colder, higher elevations there.

Governor Inslee's drought declaration should enable some farmers to tap well water and to purchase water from those with senior rights.  More help for adaptation to the 2070 climate.

Will there be excessive wildfires?  My colleagues in the U.S. Forest Service are not sure.  True, warm weather help dry surface "fuels", but will there be much lightning, an important initiator of many of our conflagrations?  Might the high pressure that has brought the warmth and low snowpack decrease the lightning frequency, reducing fires?

Although it may not be politically correct to say this, might  we find that 2070 weather has some positives?  Like a longer hiking season?  Less bugs in the mountains? More pleasant temperatures though most of the year?  Lower winter heating bills?  Less seasonal affective disorder?  Less avalanche injuries?   Forget I said it.

In short, we will soon learn whether our region, taking some aggressive steps to deal with the unusual snowpack and temperatures, is ready to take on the climate of 2070.    Scary perhaps, but a fascinating experiment.    And if we do have major problems, we will have insights into what we need to fix before 2070 is upon us and particularly our children and grandchildren.