October 1 is New Year’s Day for water in the U.S. west. This year, Californians were bidding farewell to a dry 2018 water year (October 2017-September 2018), which saw precipitation totals fall below the annual average for much of the state.
October 1 is New Year’s Day for water in the U.S. west. This year, Californians were bidding farewell to a dry 2018 water year (October 2017-September 2018), which saw precipitation totals fall below the annual average for much of the state. The return to drier than average conditions was a let-down following an extremely wet water year in 2017 that had helped bring about drought relief. This animated gif shows how the 2018 water year unfolded, using percent of normal monthly precipitation from October 2017-September 2018.
Compared to precipitation east of the Mississippi, precipitation in the West is sharply seasonal, with wetter winters and much drier summers. Rather than splitting a given year’s precipitation totals across the calendar year, experts recognize a “water year” that runs from October through the following September.
The 2018 water year in California got off to a poor start as rains and snows during October and December 2017 were hard to come by. This led to a substantial precipitation deficit as the calendar turned to 2018. And unlike the prior year, when torrential rains fell during January, the 2018 water year saw no similar rebound. Precipitation totals continued to be below-average through the first two months of 2018, before the state finally observed a month, March, where statewide rainfall totals were average to above-average.
Continue reading at NOAA.
Image via NOAA.
