It was the driest of winters, followed by the wettest of winters. For the Central Coast, the last two years have been a tale of two La Niñas, the irregular weather phenomenon associated with cold oceans and dry air.
La Niña years occur in cycles of two to seven years and typically last nine to 12 months, delivering their greatest impact to the West Coast during the winter. Meteorologist Brayden Murdock, from the National Weather Service’s Bay Area office, stops short of calling consecutive La Niña years rare, though they are not altogether common. Back-to-back La Niñas occurred in 2011-12 and 2008-09. However, the current La Niña has shown a much different face than the one that arrived in 2020-21.
La Niña years usually spell drought for the Central Coast, as storm systems hang over the Pacific Northwest, pulverizing Oregon and Washington with precipitation. Last water year, a period that runs from Oct. 1 to Sept. 30, Murdock says the Central Coast only received 40 percent of its typical annual rainfall. Specifically, from Oct. 1, 2020 to Jan. 3, 2021, the Monterey area saw only 1.4 inches of rain.
During the same time period this year, the area has already seen three atmospheric river events and approximately 9 inches of rainfall, which Murdock calls “atypical.” However, Murdock says the models are predicting a more classic La Niña for the rest of the season, with forecasted rain events expected to stay in the Pacific Northwest.
Francisco Chavez, senior scientist with the Monterey Bay Aquarium Research Institute, says the cold water brought to the Pacific by La Niña makes for a highly productive ocean, abundant with nutrients and food sources.
“The ocean is happy right now,” Chavez says.
However, Chavez says the terrestrial environment often pays for the fortunes La Niña brings to the marine ecosystem. Especially this year. The verdant landscapes created by a wet winter can turn into wildfire fodder when followed by the expected dry spring and summer.