El Niño is gone and another La Niña may form

El Niño was declared officially over by the Australian Bureau of Meteorology (BOM) last week, one of the main forecasters who monitor sea-surface temperatures. The last El Niño event lasted only seven months, which was also one the strongest and shortest ones in recorded history. As I’ve stated in previous columns, an El Niño is the abnormal warming of sea-surface temperatures in the south-central Pacific Ocean.

Ocean temperatures near the West Coast of South America, one of the indicators for the trend of sea-surface temperatures, have recently turned cooler than normal. However, water temperatures are still above average along the equatorial regions. According to the BOM, conditions in this part of the Pacific Ocean have now returned to “neutral,” or as we often refer to as a “La Nada.”

Another key indicator to determine El Niño and the cooler La Niña events is the differences in air pressure between Darwin and Tahiti. During El Niño conditions, the average air pressure in Darwin is higher than in Tahiti.

 As of early April, the U.S. Climate Prediction Center still had an El Niño event. However, they were predicting the demise of El Niño this month or by June at the latest.

 With a strong El Niño during our winter season, snowfall totals across North Idaho and the rest of the Inland Northwest, especially in the lower elevations were below seasonal normal. In Coeur d’Alene, Cliff measured a total of 51.1 inches for the 2023-24 season. His prediction made last October was for 51.4 inches, which is about as close as you can get. Our normal for the season is 69.8 inches in Coeur d’Alene.

 At the Spokane International Airport, a total of 32.6 inches of snow fell for the season, compared to a normal of 45.2 inches. In the higher mountains, seasonal snowfall totals were pretty good. At Silver Mountain, over 240 inches of snow had fallen for the season with about 362 inches reported at Lookout Pass.

 Many of the long-range computer models and sea-surface temperature forecasters are predicting that we are not expected to remain in a La Nada pattern for very long. Many of the international climate models are indicating the return of the cooler La Niña by the fall season. If a new La Niña manages to form later this year, it would be the fourth one within the last five years. According to historical records, there have never been three La Niña events, followed by an El Niño, and then the formation of another La Niña in a short period of time. Also, NOAA is also forecasting a strong possibility of another La Niña event by late this year.

If ocean temperatures continue to cool over the next six months, the chances will be higher for heavier snowfalls across the northern U.S., including North Idaho. During the La Niña winter of 2023-24, an above-normal total of 83.8 inches of snow fell in Coeur d’Alene. However, during the 2022-23 season, also a La Niña year, only 66.7 inches fell, which was slightly below average. Although, there are no guarantees that we’ll have a big snowfall season in 2024-25, but Cliff and I do believe the odds of having near to above-normal snows in Coeur d’Alene and surrounding regions are much higher.

With faded El Niño and ocean waters in the Atlantic and Caribbean waters still well above normal, the upcoming tropical storm and hurricane season may be another big one.

With the tropical storm and hurricane season officially starting June 1, it’s very possible that we could rival, or even surpass, last year’s total of 20 named storms. With ocean temperatures still above average in the Atlantic Ocean, we could see a total of named storms in the low to mid-20s if sea-surface temperatures cool down as quickly as many are projecting.

For tropical storms and hurricanes to form in the Atlantic and Caribbean waters, as well as the Gulf of Mexico, ocean temperatures need to be at least 80 degrees Fahrenheit. During the summer season in 2023, average sea-surface temperatures across these regions have been at record levels. Around the peak of tropical storm formation in early September of 2023, readings in some areas were reported to be in the mid-to-upper 80s.

In terms of our local weather, there is an increasing chance of shower activity late this month and into early May. Conditions may turn dry again, but we could see more showers and thunderstorms around the middle and the end of May, as well as early June.

Then, Cliff and I believe that the upcoming summer season will once again be dry with periods of very warm to hot temperatures. It looks like there will be at least several days this summer with highs at or above 100 degrees.

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Contact Randy Mann at randy@longrangeweather.com.