A La Niña is expected to continue into the winter months. La Niña is the cold phase of the ENSO, or El Niño Southern Oscillation. La Niña is caused by upwelling of cool deep water to the surface of the equatorial Pacific Ocean. This climate pattern can have effects on our local weather.
Typically, during a La Niña year we see warmer-than-average temperatures across the Tennessee Valley. There’s also an equal chance of seeing above or below-average precipitation.
The Climate Prediction Center released their outlook for the months of November, December and January for Huntsville and the rest of the Tennessee Valley and it seems there is no signal that sways either way for above or below-average temperatures or precipitation. There’s an “equal chance” across our area. Temperatures will likely run above average across the Desert Southwest and rainfall will likely be above average for the Pacific Northwest.
The average temperature for the months of November, December and January for Huntsville is 46.9 degrees and the average temperature for Muscle Shoals is 47 degrees. Average precipitation for these months for Huntsville is 15.11 inches and Muscle Shoals, 14.34 inches. Huntsville averages about two inches of snow per year.
For perspective, last fall and winter there was a La Niña. November 2021 and January 2022 both were below average on temperature in Huntsville. December ran well above average by 8.3 degrees. January was the only month out of the three that brought above-average precipitation with 5.87 inches. The average for January in Huntsville is 4.99 inches. January 2022 also brought 3.2 inches of snow to the city.
There are other factors such as the North Atlantic Oscillation and Arctic Oscillation that can play a role in temperatures and precipitation. When the North Atlantic Oscillation and Arctic Oscillation are both negative it can lead to more cold air outbreaks for the Lower 48 so we’ll be watching these phases during the winter. You may have also heard of the polar vortex. The polar vortex is a region of very cold air in the polar regions that’s always swirling there. A strong vortex would lead to less cold air outbreaks whereas a weaker polar vortex would lead to more cold-air intrusions into the Lower 48. We’ll be taking a look at these patterns throughout the months ahead to bring you the most accurate forecast.
For a look at how La Niña can impact severe weather season: https://whnt.com/weather/valleywx-blog/second-severe-weather-season-fast-approaching/
For more on the difference between La Niña and El Niño: https://whnt.com/weather/valleywx-blog/what-is-the-difference-between-la-nina-el-nino/