The return of La Nina. How it affects the weather

Five months after the launch of La Nina in September 2020, the U.S. National Oceanic and Atmospheric Administration announced the launch of another cooling of the Pacific Ocean.

The natural cooling of La Nina to some parts of the Pacific Ocean is on the other side of a warm El Nino form and results in kinetic changes in world weather for months and sometimes even years. But changes vary from place to place and are uncertain, but trends.

According to a 1999 study by La Nina, El Niோo and neutral conditions tend to cause more agricultural damage and drought in the United States. Agriculture in the United States.

How strong is it and how long will it last?

Mike Holbert, deputy director of the National Oceanic and Atmospheric Administration (NOAA) Climate Forecast Center, said there was a 57 percent chance it would be a moderate La Nina, with only a 15 percent chance it would be strong.

He added that since the second year of La Nina in a row does not generally match the first year, it is unlikely to be as strong as last year.

This La Nina is expected to last until spring, Holbert said.

See What the Year of La Nina means:

What does this mean for the weather?

In Canada, La Nina is often associated with winter weather, with above-average rainfall in British Columbia, colder grassland temperatures than normal, and above-average rainfall and snow in Ontario and Quebec. According to Environment Canada.

In the entire southern third of the United States, especially in the southwest, La Nina means mostly dry, hot weather. The West has been hit by the worst drought in two decades.

But Holbert said La Nina is a good opportunity to get relief from rain and drought in the northwest – Washington, Oregon and parts of Idaho and Montana.

“Good for them, maybe not so good for Central and Southern California.”

The Ohio Valley and the Northern Plains are wet and cold. Winter in La Nina tends to move the winter blizzard further north, while places like the mid-Atlantic are often unaffected by major blizzards.

In general, it can be expected to be cold in western Canada, southern Alaska, Japan, the Korean Peninsula, western Africa and southeastern Brazil.

Much of Southeast Asia and northern Australia have high humidity in La Nina – which is already evident in Indonesia, Holbert said. Central Africa and southeastern China are generally arid.

See Hurricane Ida calms down in New Orleans as rescue efforts begin:

Hurricane Ida left New Orleans quiet as rescue efforts began

Hurricane Ida has almost devastated New Orleans, most of which are still without electricity or water, rescue efforts are beginning in earnest and residents are struggling to cope. 2:31

What about the hurricane period?

During La Nina last year, there were 30 named storms in the Atlantic. This year, without La Nina, the season was busier with 20 named storms than usual and the only unused name on the primary storm name list: Wanda.

The last two weeks have been quiet, but Holbert said he expected things to return to normal. “Just because it’s quiet now doesn’t mean we won’t see more storms as we approach October to November.”

La Nina tends to change the Atlantic seasons more actively because the wind above is an important part of storm formation. El Nino storms cause more winds to blow over the heads, while less winds blow over La Nina, allowing storms to form and grow.