Expect More ‘Climate Surprises’ With California’s Water Supply

Water managers are preparing for a warm winter, a worse drought and a chance of biblical floods. As California discovered last year, the weather can swing wildly from one extreme to the next each month—offering little reliability for farmers planting winter crops or planning for the next irrigation season.

Conditions are lining up for a rare third year of La Niña, which tends to bring heavier precipitation to the Pacific Northwest and drier weather to most of California. Last year two atmospheric rivers delivered the bulk of the water supply in October and December, with total precipitation adding up to 76% of average for the water year that ended last month. But the last two winters have demonstrated that an adequate snowpack can disappear in just weeks under spring heat waves.