A high pressure ridge off the coast of California has turned off
the tap that provided above average moisture to the Sierra
Nevada during December. A graph issued by the National Weather
Service this afternoon comparing this year's snow water
equivalent and the 30-year average for the Sierra Snow Lab near
Donner Pass. "The water year started out fairly average through
the first half of December, then snow water equivalent rapidly
increased above average for late December," forecasters said.
"There has been very little additional accumulation since the
end of December and now the region is anomalously low." Totals
vary from one part of the central Sierra to another, forecasters
said the trend is shared for all locations. "In general, strong
high pressure has been situated off the coast of California
since the beginning of January with only a few transient storms
moving through," according to the report. "Ridging is disrupting
the flow of moisture that would feed any storm systems moving
through California and