La Niña Arrives in the Pacific: What Can Be Its Effects on Hurricanes and Wildfires

By Mary Anne R. First Posted: Sep 12, 2020 12:39 AM EDT

La Niña conditions were observed to be forming in the Pacific Ocean last month.

National Oceanic and Atmospheric Administration (NOAA) forecasters said there is a 75 percent chance that the weather pattern will persist through winter.

Reports said there could be an increase in activity during the ongoing Atlantic hurricane season and create conditions more prone to wildfires out West.

La Niña is a naturally occurring phenomenon wherein sea surface temperatures across the central and eastern Pacific Ocean are cooler than average. It is the opposite condition of the warmer-than-average El Niño.

Scientists believe this time, the condition will last through at least until February.

"La Niña can contribute to an increase in Atlantic hurricane activity by weakening the wind shear over the Caribbean Sea and tropical Atlantic Basin, which enables storms to develop and intensify," Mike Halpert, the deputy director of NOAA's Climate Prediction Center, said in a report.

According to reports, La Niña's arrival could affect weather around the world, which could cause more frequent and stronger hurricanes.

It can also mean wetter conditions for northern Australia, Indonesia, and the Philippines, while this could pose drier conditions for western South America and cooler conditions for western Africa.

In July, the NOAA issued a La Niña watch, giving warning that the weather phenomenon could form in the fall. La Niña weakens winds between the ocean surface and the atmosphere's upper levels, allowing hurricanes to grow more easily.

It also affects the jet stream's position over North America, which can influence the track and severity of winter storms. This can make wetter and cooler winters along the Pacific Northwest and areas currently experiencing wildfires.

Research is beginning to show how a warming climate may amplify the effects of El Niño and La Niña. A 2018 study on atmospheric conditions ran simulations of climate conditions.

The study found that climate change could increase the severity of weather events stemming from El Niño patterns. In addition, climate change might mean that some older temperature patterns linked to El Niño and La Niña no longer apply.

Meteorologist expert Brandon Miller said that 2020 is already trending as one of the top two warmest years on record.

"Perhaps a cooling influence from an emerging La Niña will keep it out of the top spot, but will likely still be in the top 3 at least," Miller said in a report.

Miller noted that top spots on the warmest years' list used to be reserved for the strong El Niño years. However, human influences have overwhelmed the planet's natural temperature.

Last month, the NOAA predicted 19 to 25 named storms for 2020. Seven to 11 storms are seen to become hurricanes, with three to six of those have been forecasted to be major hurricanes of category 3 or stronger. The update covers the six-month hurricane season that started June 1 and ends in Nov.

"This year, we expect more, stronger and longer-lived storms than average, and our predicted ACE range extends well above NOAA's threshold for an extremely active season," Gerry Bell, lead seasonal hurricane forecaster at NOAA's Climate Prediction Center, said in a report.