WASHINGTON – After three sordid years, the La Nina weather phenomenon in the Atlantic that increases wind activity and worsens the Western drought is gone, the National Oceanic and Atmospheric Administration said Thursday.
This is usually good news for the United States and other parts of the world, including the drought in North Africa, scientists say.
The globe is now in what is considered a “neutral” situation and will likely trend toward El Nino in late summer or fall, said climate scientist Michelle L’Heureux, head of NOAA’s El Nino/La Nina forecasting office.
“It is,” said research scientist Azhar Ehsan, who heads Columbia University’s El Nino/La Nina forecasting program. “Mother nature thought this one thing was enough to get rid of.”
La Nina is a natural and temporary cooling of parts of the Pacific Ocean that changes the weather around the world. In the United States, because La Nina is associated with more Atlantic storms and deeper droughts and fires in the West, La Ninas are often more severe and costly than their more famous flip side, El Nino, experts said and studies show.
In general, American agriculture is more affected by La Nina than by El Nino. If the group jumps into El Nino, it means more rain for the Midwestern corn belt and could benefit, said Michael Ferrari, chief scientific officer of Clima Alpha, a firm that advises investors on climate-based financial decisions.
When it’s La Nina, there are more storms in the Atlantic during the storm season because of conditions that suppress storm formation. Neutral or El Nino conditions make it more difficult for hurricanes to emerge, but not impossible, scientists said.
In the past three years, the US has been hit by 14 hurricanes and tropical storms that have caused millions or more in damage, with $252 billion in costs, according to NOAA economist and forecaster Adam Smith. He said La Nina and the people were the factors in his loss.
Climate change is a major factor in increasing extreme weather, according to La Nina, scientists and many studies and reports show. Human-caused warming is like an ascending escalator: it increases temperatures and makes extremes worse, while La Nina and El Nino are like jumping up and down on an escalator, according to Northern Illinois University of the Arts professor Victor Gensini.
La Nina also weakened average global temperatures slightly, keeping warming from breaking annual heat records, while El Nino slightly turbocharges those temperatures, scientists said.
La Nina tends to make West Africa wet, but East Africa, around Somalia, is dry. The opposite happens during El Nino when drought-stricken Somalia is likely to receive steady “short rains,” Ehsan said. La Nina has very wet conditions in Indonesia, parts of Australia and the Amazon, but these areas are drier during El Nino, according to NOAA.
El Nino waves mean more heat in India and Pakistan and other parts of South Asia and weaker winds there, Ehsan said.
This particular La Nina, which began in September 2020 but was considered three years old because it affected three different winters, was unusual and one of the longest on record. He took a short break in 2021, but came roaring back with record intensity.
“I’m sick of this La Nina,” Ehsan said. L’Heureux nodded, saying that he was ready to talk about something else.
A few other times that the triple dip La Ninas have come after strong El Ninos and there is a clear physics behind why that happens. But that’s not what La Nina happened, L’Heureux said. She has not had this strong El Nino before.
Although this La Nina has previously baffled scientists, they say the signs of leaving are clear: Water in the central Pacific Ocean warmed slightly more than the threshold of La Nina in February, the atmosphere showed some. changes and according to the eastern Pacific near Peru, already El Nino-like heating brewing on the coast L’Heureux said.
Think of a La Nina or El Nino as something that pushes a weather system out of the Pacific with ripple effects around the world, L’Heureux said. When conditions are neutral like now, there is less pressure from the Pacific. This means that other climatic factors, including the long-term warming trend, are more effective in long-day weather, he said.
Without El Nino or La Nina, forecasters have a more difficult time predicting weather trends for the summer or fall because the Pacific Ocean has such a large footprint in weeks-long forecasts.
El Nino predictions made in the spring are generally less reliable than those made at other times of the year, so scientists are less confident about what’s coming next, L’Heureux said. But the NOAA forecast said there is a 60% chance that the El Nino charge will come.
There is also a 5% chance that La Nina will return for an unprecedented fourth dip. L’Heureux said that he did not really want to, but that a scientist would find pleasure in it.
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