La Niña the influencer

La Niña will play a role in your winter weather — she’s an influencer. La Niña is neither a storm nor a single day of weather, but it does shift average weather patterns. You can’t blame or credit La Niña for any single weather system.

La Niña is when the central and eastern Pacific Ocean along the equator is cooler than average, with slightly stronger east to west winds. Those winds push the warmer water to the western Pacific. When this pattern persists over many months, it’s known as La Niña. La Niña, Spanish for “the girl,” is the opposite pattern to her brother, El Niño. The name El Niño came from fishermen on the west coast of South and Central America, who noticed warmer-than-average water temperatures around Christmastime. El Niño is “the boy” or “the Christ Child.”

El Niño and La Niña are significant because temperature changes in the expansive Pacific cause shifts in the average steering winds and jetstream position. That causes some regions to be warmer or cooler, and/or wetter or drier. In the case of La Niña, it tends to push the winter jetstream a little more to the north over North America, so we get a warmer and drier pattern.

Warmer-than-average and slightly drier-than-average is the winter outlook for the northern Gulf Coast, according to NOAA, the National Oceanic and Atmospheric Administration. Seasonal outlooks are most relevant for agriculture, recreation, transportation and other weather-dependent industries.

Just as in a hurricane season outlook, no outlook is meant to be taken as a daily forecast or as a guarantee, especially for a single city or county. These are broad averages for long periods, like months, for large geographical areas, like continents, making an outlook more climate than weather. Weather forecasts are updated frequently and target small areas. Climate outlooks are only issued periodically.

Even with a warmer and drier winter outlook, be prepared for the weather extremes that can happen in winter, such as outbreaks of record cold, days of rain and maybe flooding, and severe weather. Averages are what you expect, but weather is what you get. Part of that reality is it’s still possible to deal with tropical storms or hurricanes through November. There could even be tropical threats in December, although that’s rare.

La Niña and El Niño have other impacts in other seasons. Neither is easily predicted for when it starts or exactly when it ends. Either could last a few months or many months. They don’t happen on regular cycles, and they don’t necessarily alternate. Once either sets in, there are usual shifts elsewhere. La Niña will influence our overall winter weather, but not in a way that tells us the local weather in a week.

Alan Sealls is chief meteorologist at NBC15 and an adjunct meteorology professor at the University of South Alabama.