According to the National Weather Service Climate Prediction Center, it’s likely that a rare La Niña three-peat will happen this winter. The August ENSO Blog says, “The chance that the current La Niña will last through early winter is over 70%. If it happens, this will be only the third time with three La Niña winters in a row in our 73-year record. ENSO (El Niño/Southern Oscillation, the whole La Niña and El Niño system) has the greatest influence on weather and climate during the Northern Hemisphere cold season, so forecasters pay especially close attention when it looks like ENSO will be active in the winter.” La Niña generally means a colder, wetter winter in the northwest - which usually delivers above-average snowfall.
The diagram above depicts a generalized Walker Circulation (December-February) anomaly during La Niña events
La Niña is present when the sea surface temperature in the east-central Pacific Ocean is at least 0.5 °C (0.9 °F) cooler than the long-term average, along with evidence of a stronger atmospheric circulation above the equatorial Pacific.
The forecaster consensus, supplemented with the latest models from the North American Multi-Model Ensemble (NMME), concurs that La Niña is the most likely outcome during the fall and winter.
Synopsis: La Niña is expected to continue, with chances for La Niña gradually decreasing from 86% in the coming season to 60% during December-February 2022-23.
Meanwhile - the Farmer’s Almanac for 22-23 is out and forecasting a fairly harsh winter, saying, “According to our extended forecasts, this winter season will have plenty of snow, rain, and mush—as well as some record-breaking cold temperatures!”
But what’s in store for the Pacific Northwest? Residents in Oregon, Washington, and Idaho can look forward to “Brisk Normal Precipitation,” according to the Farmer’s Almanac.
Although the first day of winter is officially Dec. 21, the Farmer’s Almanac says it will start feeling like winter earlier this year than last year for many across the U.S.