Weather's unwanted guest: Nasty La Nina keeps popping up

There is something weird about LaNina, the natural but potent weather event that is linked to more fire in the west and more Atlantic hurricanes. It is becoming the nation's unwanted weather guest and the West's megadrOUGHT won't go away until La Nida does.

The current double-dip La Nina set a record for strength last month and is expected to be around for a third straight winter. It is not just this one. In the past 25 years, the world seems to be getting more La Ninas than it used to and that is not what the best computer model simulations say should be happening with climate change.

The head of the National Oceanic and Atmospheric Administration forecast office for La Nina and its more famous flip side, El Nio, said that they don't know when to leave.

In the past 25 winters, the La Ninas have been brewing nearly half the time, but an Associated Press statistical analysis shows that they used to happen about 28% of the time from 1950 to 1999. There is a small chance that this effect could be random, but if the La Nina sticks around this winter, that would push the trend over the statistically significant line. In the last 40 years, her analysis shows that there are more La Nina-like conditions. Similar patterns are being shown in other new studies.

Climate simulation models that tend to get conditions right over the rest of the globe predict more El Nios, not La Nia, and that is causing contention in the climate community about what to believe.

Seager and other scientists said that the eastern equatorial Atlantic is not warming as fast as the western equatorial Atlantic or the rest of the world. The difference between the west and east is more important than the amount of warming. The less the difference, the more likely it is that there is an El Nio. It could be related to another natural cycle, called the Pacific Decadal Oscillation, or it could be caused by human-caused climate change.

L Heureux said that they don't know at this point. It is important because of regional conditions. We need to get this right.

The cooling of the parts of the Pacific that make up the equator is called LaNina and it changes weather patterns around the world. Studies show that the United States is more vulnerable to hurricanes, less rain, and more fires because of La Nia than it is because of El Nio. One of the largest natural effects on climate, at times augmenting and other times offsetting the big effects of human-caused climate change from the burning of coal, can be found in the ENSO, which stands for El Nino Southern Oscillation.

Azhar Ehsan, a research scientist at Columbia University, said that a third consecutive La Nina is not a good thing.

He said the heat in India and Pakistan is connected to the La Nina weather pattern.

When the Atlantic set a record for the number of named storms in the summer of 2020, the current La Nina formed. It strengthened in the winter when the West's dry spell worsened and weakened in the summer of 2021. The pause only lasted a few months and by the fall of 2021, La Nina was back, making it a double dip.

Ehsan said that in April the La Nina set a record for intensity, which is based on sea surface temperatures.

L Heureux said that these are very impressive values for April. There is a small but increasing chance that this La Nina could warm just enough to be considered neutral in late summer.

It is a problem for the West when La Nina is in the winter because it is the rainy season that is supposed to replenish the water in the basins. The West is in a 22-year megadrought, which coincides with an increase in La Nina Frequency.

Climate change and randomness are the biggest factors when it comes to the drought, according to a UCLA climate scientist. Without climate change, the La Nina weather phenomenon could have made the drought worse in 300 years, but with climate change it is the worst in at least 1,200 years.

It may be the dominant player, and it could be responsible for one-third or one-half of the conditions.

It is less likely that the Southwest will see a partial recovery from the megadrought.

Colorado State University's Phil Klotzbach said that La Nia increases your Atlantic storms but decreases them in the Pacific.

The winds are between 6 to 7 miles above the water surface. Wind shear is one of the key factors in storm development. Hurricanes can be hard to strengthen and even stick around if they are decapitated by wind shear. Dry air can enter hurricanes that choke them.

It is hard for hurricanes to get going when there is lots of Atlantic wind shear. The lack of wind shear in the Atlantic makes it easier for storms to intensify and do it quickly.

That is a huge factor, Corbosiero said.

Emanuel said that the increasing incidence of La Ninas may be behind the increasing hurricanes.

The arid region of Africa and eastern Australia do better with more rain. Ehsan said that India and Pakistan get more needed rain because they get extra spring heat.

The 1999 economic study found that the United States lost between $2.2 billion and $6.5 billion due to the La Nina weather phenomenon. A neutral ENSO is good for agriculture.

Even though there may be a chance of some natural cycles behind the changes in La Nina, Seager thinks there will probably be more of them because of the climate change factor.

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