Climatologists: El Nino coming, could be a strong one

By Don Jenkins; Capital Press

Federal climatologists Thursday predicted the return of El Nino, a phenomenon associated with warm Northwest winters and low snowpacks.

The odds favor a weak El Nino forming between May and July and gaining strength in the fall, according to the National Weather Service’s Climate Prediction Center.

The center projected a 41% chance that a strong El Nino will prevail by the winter.

It would be the first strong El Nino since 2014-15, a winter of historically low snowpacks in Oregon and Washington, and the first El Nino of any strength since 2018-19. El Nino’s opposite, La Nina, has reigned the past three winters.

Spring forecasts are shaky, but wind anomalies and a wave of warm water moving toward South America support the prediction that El Nino will come, according to the climate center.

“It looks like a very solid bet,” Washington State Climatologist Nick Bond said. “The seeds for an El Nino are there.”

An El Nino forms when Pacific Ocean temperatures along the equator are at least 0.5 degree Celsius above normal. Temperatures at least 1.5 degrees above average make for a strong El Nino.

Temperatures in the mid-Pacific are about normal, but are 2.7 degrees above average off the cost of Ecuador. In a statement, the Climate Prediction Center called the warmup “striking.”

“The coast warming in the eastern Pacific may foreshadow changes across the Pacific Basin,” according to the center.

Mid-Pacific temperatures only recently warmed up to normal, finally ending last month La Nina’s three-year reign. La Ninas are linked to wet and cold winters in the northern U.S. and dry and warm winters to the south.

This past winter didn’t fit that pattern. Snowpacks in California, Nevada, Utah and Southern Oregon were large, while Washington’s snowpack was average. “In a way the winter has been a disappointment in terms of the snowpack,” Bond said.

The average, or “neutral,” sea-surface temperatures are not expected to last. The climate center put the odds of an El Nino forming between May and July at 62%. The odds swing to favor a moderate El Nino in the fall.

Bond said he doubted an El Nino would have much influence on the Northwest’s summer weather. El Nino would more likely be felt in the fall and winter, raising freezing levels and reducing snow accumulations, he said.

During the last strong El Nino, Washington’s snowpack on April 1 was 22% of normal, the lowest on record, according to the Natural Resources Conservation Service.

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