California Officials Say Not to Bank on a Drenching El Niño

Forecasters are increasingly, cautiously optimistic about relief coming to ease California’s drought, thanks to the strengthening of the El Niño weather pattern.

There’s an 85 percent chance of a strong El Niño sticking around through next spring, according to forecasters at the National Oceanic and Atmospheric Administration. Its strength should peak in the late fall and early winter, just the right time to deliver soaking storms.

But California officials pushed back on Thursday, warning that the strong forecast won’t guarantee the rainfall the state desperately needs.

“California cannot count on potential El Niño conditions to halt or reverse drought conditions,” said state climatologist Michael Anderson in a statement. “Historical weather data shows us that at best, there is a 50/50 chance of having a wetter winter. Unfortunately, due to shifting climate patterns, we cannot even be that sure.”

California saw extreme rainfall and flooding when conditions were similar in winter 1997-8. But look back to the previous seven strong El Niño events since 1950 and three actually produced dry years.

Some forecasters also point to the ridge of high pressure that has dominated recent winters and pushed incoming storms away from Northern California. It could be a potential spoiler for the rain an El Niño could bring.

Warmer temperatures this winter could also mean the precipitation would fall as rain, instead of snow. Snowpack in the Sierra Nevada is California’s “frozen reservoir,” normally producing a third of the state’s water supply as it melts.

“I’m not saying I don’t want an El Niño, I just don’t want folks to think we don’t have to conserve because El Niño will save us,” said Felicia Marcus of the State Water Resources Control Board. She says El Niño hype risks derailing the conservation efforts underway.

The water board is in the midst of enforcing mandatory water conservation standards, up to 36 percent, for water districts around the state. In June, about a third of districts failed to meet those standards and could face fines from the state.

Scientists also say the state would have to get about double its normal precipitation to make up the rain and snow deficit built up during the drought.