El Niño’s Southland washout
Rising global temps, warmer ocean waters and storms conspired to block the system.
A mix of rising global temperatures, mysteriously warmer waters off Baja California and unusually farreaching storms in the western Pacific Ocean conspired to block this year’s El Niño storms from hitting Southern California, the National Weather Service said last week.
Despite plenty of indicators suggesting that the 201516 El Niño rains would be as strong — if not stronger — than previous Southland El Niños, heavy precipitation failed to materialize. Instead, the storms flowed north from the Bay Area to Washington, drenching the northern Sierra Nevada and refilling some of the state’s biggest reservoirs.
In recapping this year’s El Niño phenomenon — the first since the winter of 199798 — the National Weather Service said the pattern “flipped” from previous El Niños that left the Northwest relatively parched and the Southwest soaking wet.
Although experts anticipated that February would be the wettest month of the year for Southern California, it was actually the driest in 30 years — because of El Niño’s influence.
Data suggest this was due in part to the “blob,” an unrelated warming of the waters along the North American West Coast from Alaska south to Baja California. The warmer waters off Baja may have helped “enhance” a high-pressure ridge that stretched up to California, diverting incoming storms to the north, the weather service said.
Experts also suggested that rising global temperatures may have affected the jet stream over the Pacific, which further helped steer incoming storms north toward the Bay Area and beyond, the weather service said.
“It’s important not to assume that El Niño events of the future will behave the same,” the report said. “But there is much to learn about how changing background conditions impact such atmospheric [conditions] ... through the remainder of this century.”
The National Weather Service said that as El Niño continues to weaken, it appears it will soon make way for its counterpart, La Niña, which could bring a drier-than-average winter.