Even if this rainy season does little to end California’s drought – 2013 had the lowest precipitation in the state’s recorded history – next winter might do the trick.
Rain storms have drenched much of the Bay Area in recent weeks, which has helped lessen the severity of the drought, but the governor’s drought emergency declaration of Jan. 17 still stands.
However, early indications are pointing to a weather phenomenon developing in the next few months.
“If we get a strong El Niño, we feel more confident that it will rain more than normal in Northern California,” said Logan Johnson of the National Oceanic and Atmospheric Administration.
That’s because warming water temperatures off the coast of Peru could mean that an El Niño rainy season next winter is in store for California.
El Niño, a weather pattern that brings increased rain to California and fluctuates from year to year, is produced when equatorial waters in the eastern Pacific Ocean warm up. That warm water, due in part from weakened trade winds, creates more storms and rain along the West Coast.
In La Niña years, when the trade winds blow harder, equatorial waters in the eastern Pacific are colder and result in fewer storms in California.
El Niño and its dry-weather counterpart, La Niña, have no real regularity, said Katryn Wiese, a professor of geology and oceanography at City College of San Francisco. Sometimes one cycle will last for five to seven years and sometimes they will switch every few years, she said.
The last El Niño occurred in the winter of 2009-10, and perhaps the most memorable recent El Niño was the very wet winter of 1997-98, according to NOAA.
Whether or not the early signs of an El Niño season will develop into a strong rainy season remains to be seen, said Johnson. The warm waters could just produce a weak El Niño.
In the meantime, recent rains have put a dent into the drought in the Bay Area, according to NOAA.
San Francisco’s drought status has been reduced to an extreme drought, as has much of the North Bay, while the East and South bays remain in an “exceptional’ drought. But despite the rains, San Francisco is still 10 inches below normal when it comes to accumulated rainfall by this time of year, according to the National Weather Service.
A heavy rainy season next year shouldn’t blind San Franciscans to the fact that we remain in a serious drought, said Johnson. “What’s important right now is that people don’t see this report and think we don’t have to worry about water conservation and drought,” he said.