The official “rainy season” for Southern California starts October 1 and continues through April 30. October brought Southern California heat and dry offshore wind days as a strong ridge of high pressure lingered along the coast. Areas in Los Angeles experienced a stretch of 3 consecutive days over 100 degrees. November has provided the Pacific Northwest with wetting rains, but extreme Southern California has been left in the dry without any wetting rains.
For the remainder of the Northern Hemisphere fall and winter 2017-18, a weak La Niña is favored in the model averages with an approximately 65-75% chance that La Niña conditions will continue through the Northern Hemisphere winter fueled by cooling waters in the equatorial Pacific Ocean. La Niña often leads to below normal precipitation for California, especially Southern California.
The seasonal temperature and precipitation outlooks below from NOAA’s Climate Prediction Center were updated on Thursday November 16th. The outlooks provided below generally favor above-average temperatures and below-median precipitation across the southern tier of the United States, including Southern California, and below-average temperatures and above-median precipitation across the northern tier of the United States.
What to expect this winter? The latest forecasts indicate this “rainy season” will likely be drier or possibly much drier than normal. And if the Northern Hemisphere fall and winter 2017-18 is drier than normal as is currently forecast, it would be the 6th dry winter out of the last 7. Which means that it is possible drought could re-emerge in areas of California.
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