Snow Drought in the Sierra Nevada Mountains
The Sierra Nevada Mountains are officially in a snow drought, receiving less snow this year than what is normal.
Over the past four years, we've seen snow drought occur in some way shape or form, a trend that caught researchers at the Desert Research Institute (DRI) and Western Regional Climate Center's (WRCC) eyes. With that curiosity, Dr. Benjamin Hatchett and Dr. Dan McEvoy just published a paper evaluating snow droughts in the Sierra Nevada Mountain Range (full article--- available here).
McEvoy explains that snow drought is not a new concept for our climate, but there is something different about the 21st century:
"Back in the day there has always been fluctuating snow levels in the sierra. There's always been warm storms...There has been rain at lake level as far back as you can remember...But over the past four years we've seen snow droughts occur over all the last four seasons in some way shape or form."
A staggering statistic as our climate continues to change, and this year has been unique Hatchett says:
"This year has been quiet interesting because it's really highlighted what we are calling 'all of the above'... All the different kinds of mechanisms that can get us into snow drought we've been seeing this year."
We are currently on pace with the 2015 year, which is not good because research has suggested 2015 was the lowest snowpack in the Sierra dating back 500 years.
Snow droughts have been increasing in recent history, and although 2017 was one for the record books, we still experienced a type of snow drought -- we saw heavy rain wash away snow in the early 2017 snow season.
The Tahoe area snowpack is currently at 25-30 percent of the long-term average.
However, thanks to last year's record snow, our reservoirs are sitting high.
So our water supply should be okay as we go into the summer, but we won't be making any significant deposit into our water bank this year.
But McEvoy explains we don't know what spring weather lies ahead and it's not atypical to see a "Miracle March" boost Sierra snowpack:
"However we could shift to a wetter pattern going into late February and March ... But we don't know yet ... So we could have improvements but it is going to be very difficult to get above average at this point."