California’s storm door is about to swing wide open – San Francisco Chronicle

California’s storm door is about to swing wide open  San Francisco Chronicle

An atmospheric fire hose could soon take aim at California, raising the prospects of a wet and stormy Halloween and Election Day. The massive pattern change is likely to take shape during the last week of October and may persist into the first full weekend of November. Read more: These California highways are most at risk of flooding during El Niño storms Also: California’s oceans have become shockingly warm. And strange things are happening Related: San Francisco declares emergency ahead of expected wet El Niño winter Some of the precipitation numbers being advertised by weather models are impressive. At this time range, over a week away, meteorologists use ensemble weather models, collections of forecasts run with small variations to represent multiple outcomes.

Several models are calling for upward of 1 to 3 inches of rain around the Bay Area by the first weekend of November, from a likely atmospheric river. Even more precipitation is forecast for Southern California and the Sierra. Exact amounts aren’t guaranteed by any means at this time range, but the trend is hard to ignore. California is primed for rain this winter, in part due to unusual ocean heat associated with this year’s extremely powerful El Niño. Tropical Pacific surface and subsurface water temperatures have been high for months. Parts of the equatorial Pacific are running