Could we see a La Niña and El Niño in the same year?

A new La Niña was declared by forecasters at the Climate Prediction Center (CPC) in October and by the Australian Bureau of Meteorology several weeks ago. Sea-surface temperatures near the West Coast of South America and along the equatorial regions have been cooler than normal over the last six weeks as La Niña conditions were indicated by the CPC in September and October. Despite the recent declaration of this phenomenon, forecasters are predicting that this new La Niña is expected to be weak and only persist through the first two to three months of 2026.

The latest sea-surface temperature charts do show a stretch of cooler-than-normal sea-surface temperatures along the equatorial regions. However, there is a region of warmer-than-normal sea-surface temperatures along the immediate coastline of the West Coast of South America. This is an area that is watched very closely as the warming and cooling in this region can determine whether we will have a future La Niña or El Niño.

Despite the onset of a new, cooler La Niña event, ocean waters across the rest of the globe are near to above normal levels. Some ocean regions near the equatorial regions in the North Pacific are over 4 degrees above average.

Most of the computer forecast models are showing that in February or March 2026, conditions should return to a “La Nada,” or in-between the warmer El Niño and cooler La Niña pattern. There are also indications that a rapid warming of ocean waters along the equatorial regions may be seen in mid-to-late 2026 that would lead to the declaration of a new El Niño. If this were to occur, we would have a La Niña and an El Niño within the same year. Right now, the odds of that happening are less than 50/50. Back in 2023, there was a big shift from a strong La Niña to an El Niño pattern.

In the meantime, forecasters continue to watch the infamous “polar vortex” that has been making news in recent weeks. As I mentioned earlier, the polar vortex is a relatively large upper-level low-pressure system consisting of large masses of cold, dense Arctic air that is located near the North Pole. When the polar vortex is strong, the frigid cold air mass will often stay confined near the North Pole as the Jet stream increases in strength. But when the vortex weakens and splits into two or more vortices, the cold air will often push southward. Therefore, the cold and snowy weather has been east of Coeur d’Alene and mostly over the central and eastern portions of the country.

With the colder air to the east, our region has been in the warmer sectors of storm systems. Although moisture levels have increased since last month, it has been mild as most of the precipitation has fallen as rain. High temperatures last week were above average, with readings in the 50s in the lower elevations.

The long-range forecasts are pointing to the relaxation of the polar vortex, resulting in a stronger influence from the new La Niña. During La Niña events, moisture totals will often increase across the northern U.S., especially here in North Idaho. Despite the warmer waters in the eastern Pacific Ocean, we still have a better chance of higher snowfalls during the winter season. Some of the forecasts are still predicting above-average snowfalls across the inland portions of the Pacific Northwest, the Great Lakes region and across parts of the southern Midwest.

By contrast, below normal snowfalls are forecast across the mountains in the southwestern U.S. This may also include California’s Sierra Nevada mountains. As of the middle of December, snowpack levels in the Sierra Nevada mountains are approximately 30% of normal, as the air mass from storm systems has been too warm. Since the beginning of the rainfall season July 1, moisture totals in the Central Valley of California are above average levels. In fact, it has been wet in Southern California as Downtown Los Angeles has reported over 7 inches of rain since July 1, more than three times their normal to date.

The weather pattern this week across the Inland Northwest will continue to have a series of Pacific storms move into the area. It still looks like most of the moisture that falls will be in the form of rain in the lower elevations. However, toward the end of the week, the air mass is expected to be a little colder, which will lower the snow levels to approximately 2,500 feet.

It's going to be very close once again for a White Christmas in Coeur d’Alene and the surrounding regions. The long-range computer models are indicating a colder weather pattern around Christmas Day, so any moisture that does fall would likely be in the form of snow. Stay tuned.

As I mentioned last week, you can see the snow in real time at North Idaho College. A snow stick and web camera were set up to show accumulated snowfall totals and there is a viewer over the previous 24 hours to show the conditions and accumulating snowfall. The website also has temperature, humidity and air quality data. It was largely put together by NIC Professor Bill Richards and is located at https://br1.nic.edu/webcam01/.

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Contact Randy Mann at [email protected].