Most of the computer models are pointing toward the present moderate La Niña conditions persisting through the upcoming winter; for the third consecutive year. And given the past three years have seen below-normal rainfall across most of California, the immediate knee-jerk reaction has been that this will automatically be a fourth dry year, based on the misconception that La Niña always equals Dry for California. But a close inspection of past La Niñas since 1950, shows that this is not always the case. An updated detailed analysis can be found at https://www.ggweather.com/ca_enso2021/ca_lanina.html. (See the bottom of this email for other related links)
From that analysis:
To me, the important takeaways are to be wary of "average" or "typical" La Niña conditions and to look at the range of data from which those averages are derived. And most importantly, climatology is NOT a forecasting tool, but it does give context to any categorical proclamation about the prospects for the upcoming season.
El Niño - La Niña Resource page: https://ggweather.com/enso.htm
Current Oceanic Niño Index (ONI): https://ggweather.com/enso/oni.htm
La Niña and California Rainfall: https://www.ggweather.com/ca_enso2021/ca_lanina.html
El Niño and California Rainfall: https://www.ggweather.com/ca_enso2021/ca_elnino.html
ENSO-Related US Winter Precipitation: https://ggweather.com/enso2021/
As always, comments and suggestions are welcomed.
Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services