Such impacts have been associated with past episodes, but all impacts aren't seen with every episode. San Diego ended up 2.5 inches above average and Los Angeles 4 inches above the 1981-2010 average, both of which were roughly 25% higher than average. Meanwhile in southern California, the numbers were not as large but still impressive. San Francisco rainfall totals were 10 inches above average. It was the second wettest water year since 1950 with a total of 13.6 inches above average. Los Angeles and San Diego also observed a large increase in rainfall at the same time, although not as astounding as the totals farther north in the state.īy the end of the 2016-17 water year on September 30, the Sacramento station had received almost 34 inches of rain. During the months of January and February, San Francisco and Sacramento received almost a year’s worth of rain, skyrocketing the seasonal precipitation totals. Things simply got out of hand once the calendar turned over to 2017. The plot shows that up until the start of December 2016, the water year in both northern and southern California was looking pretty average, running only slightly above-average. To give us a good look at how last year’s rainy winter played out across the state, I’ve taken weather station data from four major cities-San Francisco, Sacramento, Los Angeles and San Diego- and calculated a running accumulation of precipitation for the entire water year, starting on October 1 and ending on September 30 the next year. California wasn’t just wetter than normal it had its third-wettest year on record! That’s not how things, played out, though. And the black dotted line is the 1981-2010 average of water year accumulated precipitation. The blue line refers to the previous water year, 2016-2017. Orange line refers to the current, 2017-2018, water year. Accumulated precipitation for each water year (October-September) from 1950 to present in four cities in California. Sacramento San Francisco Los Angeles San DiegoĬlick tabs to toggle between cities. It was a reasonable outlook given that La Niña suggests drier conditions in southern California. The winter outlook for California, meanwhile, did not forecast a slam dunk for any outcome: it showed an increased chance of drier conditions in southern California and an equal chance of above, below or normal precipitation in northern California. You can read exactly what we were thinking about ENSO right before the 2016-2017 winter here (1). The rainfall during last winter in California probably falls in that “not-so-much” category. Even so, we can use the state of ENSO as a “hint” of what may be in store. NASA MODIS/TERRA satellite image taken from NASA Worldview.įirst off, if there is one topic that we here at the ENSO Blog have covered repeatedly, it’s that when it comes to specific climate impacts, especially for the United States, an El Niño or La Niña is a guarantee of absolutely nothing. Heavy rains and higher elevation snow battered California during a multi-day atmospheric river event. Satellite image taken on January 8, 2017.

Precipitation totals san francisco