It may be raining, but not due to El Niño — yet

If you’re looking at the weather system hitting the Bay Area Thursday and the one in store for the weekend as the start of the much-hyped El Niño weather phenomenon, these are not the storms you’re looking for, forecasters said. Thursday’s storm, a cold front sweeping down from the Gulf of Alaska, which brought heavy rains and flooding to the Pacific Northwest over the last few days, did not bear the telltale signs of El Niño, which is typified by above-average ocean temperatures in the equatorial Pacific that, when really warm, tend to drive moisture toward California. While typical winter storms come in the form of a singular cold front, almost always coming from the north, storms associated with El Niño will set up as a line of rain streaming in from the tropical west, a weather pattern colloquially known as the “Pineapple Express,” said Steve Anderson, a forecaster with the National Weather Service. Here we are in mid-December, having been besieged with numerous studies and news stories foretelling the biggest El Niño event since the torrential rains of 1997-98, but where is our promised deluge? [...] experts say that the rather timid beginning of winter is no reason to doubt what’s coming, with officials from the Federal Emergency Management Agency releasing a report Wednesday on how it plans to deal with El Niño-fueled storms in California, which could inflict millions of dollars in damage this winter — from mud-soaked homes to broken levees to downed electrical lines. During the El Niño winter of 1997-98, California suffered $883 million in damage, according to the report, with 17 storm-related deaths and 40 counties declared federal disaster areas.