Expect El Niño this winter, and probably plenty of rain
This winter is likely to be a moderate-to-severe El Niño season, according to the National Weather Service.
The Mercury News says that an El Niño makes it likelier we’ll have a wet winter:
The El Niño now under way doesn’t guarantee that California will receive drenching winter rains. But the stronger the conditions and the warmer the water, the greater likelihood.
Since 1951, there have been six winters with strong El Niño conditions. In four of them, rainfall between the Bay Area and Bakersfield was at least 140 percent of normal. Some of California’s wettest winters, including 1982-83, when Coyote Creek burst its banks, flooding Alviso under eight feet of water, occurred during those strong El Niño winters.
The Mercury News story is accompanied by a nice chart showing the the rainfall in moderate and severe El Niño years.
Facebook
Twitter
RSS
Sun, August 9, 2009 10:28am
jlundell
All my comments
The chart seems to suggest that the likelihood of below-average rainfall in an El Niño year is just about equal to the likelihood of above-average rainfall.
My understanding is that El Niño tends to increase rainfall to the south of us, and decrease it to the north, with the boundary between above- and below-average rainfall being hard to predict.
Sun, August 9, 2009 11:34am
Barry Parr
All my comments
Good point. That’s certainly true if you don’t know whether this will be a moderate or severe year. And the truth is that you don’t have enough data to draw strong conclusions about the correlation between El Niño and rainfall.
Sun, August 9, 2009 3:47pm
jlundell
All my comments
KQED’s Forum had an interesting half hour a month ago on the subject, discussing the prospect for a strong El Niño and its implications for the Bay Area in particular. Worth a listen.
http://www.kqed.org/epArchive/R907100930