The latest NOAA Climate Prediction Center analysis shows that development of the warm ocean condition known as El Niño have decreased 60 to 65 percent for fall and winter. The report also indicates a strong El Niño is not expected and that a weak event is likely.
Michelle Mead, Warning Coordination Meteorologist with the National Weather Service in Sacramento, said a weak El Niño won't end the California drought.
"Unfortunately there is very little correlation between weak El Niño events and above-normal precipitation," said Mead. "In the past above-normal precip has occurred during some of these events. But, at the same time, during weak El Niño events we've seen below-normal conditions.”
Mead said El Niño is a “poor predictor” of winter precipitation across Northern California.
“Only strong El Niño events are tied to a potential for a wet winter, but that is for Southern California,” she said. “Given this latest Enso discussion and potential for a weak, if any, El Niño to develop, drought conditions are likely to continue in our area and there is not an expectation that El Niño will alleviate or end the drought conditions at this time.”
Mead said the 1976-77 California drought occurred during a weak El Niño.
"Now, that's not to say that will continue for this coming winter, rather it's just to emphasize that especially in weak El Niño events, we cannot say with any certainty what the character of the precipitation is going to be for this upcoming winter season," said Mead.
Mead said it's possible the October analysis could provide more certainty whether El Niño will develop at all.
"There's one piece of the puzzle, which is the sea surface temperatures, but we need that second piece, which is an atmospheric connection," said Mead.
Mead explained that second ‘puzzle piece’ - showers, thunderstorms and cloudiness in the mid-Pacific - have not developed.
"That's why we're still in the El Niño watch," said Mead.