Atmospheric Rivers—
BLESSING or
26 SOURCE winter 2017
CURSE?
By F. Martin Ralph and Anna Wilson
PHOTOGRAPH BY DAVE GATLEY.
COURTESY FEMA.
RIVERS OF WATER VAPOR SUCH AS THE STORMS THAT MADE LANDFALL ONE AFTER ANOTHER IN JANUARY
2017 are a major influence on precipitation in the western United States. Some carry 10-20 times the
atmospheric water vapor equivalent of the Mississippi River.
The Center for Western Weather and Water Extremes at Scripps Institution of Oceanography and its partners
are focusing on better understanding observations and predictions of ARs. The Sonoma County Water Agency
is investigating strategies related to AR effects on water supply, flooding, and ecosystem management.
