La Niña represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific. During a La Niña year, winter temperatures are warmer than normal in the Southeast and cooler than normal in the Northwest.
So what does that mean for this winter here in Lake Tahoe? In the Tahoe-Truckee area, La Niña-influenced winters tend to be drier than normal, but not exceptionally so. Historically, moderately cold La Nina events bring a wetter than normal November and December to the Northern Sierra. January through March tend to be hit or miss and precipitation less reliable. At best, any long-range winter forecast for our region is an educated guess. When forecasting Sierra weather patterns, there are no easy answers.
A La Niña setup brings the polar jet down and aims it right at the Pacific Northwest, with drier conditions over southern California. The Reno-Tahoe Area is right in between the two as you can see in the image below, so it could really go either way! A weak La Niña could bring the polar jet farther south, and a strong La Niña would keep it farther north.
Let’s pray for snow so that we are able to have a fun winter and get enough snowpack to delay next year’s fire season!