According to the UN weather agency, a La Nia weather pattern is expected to persist through the end of this year. This is the first “triple dip” occurrence of the century, which describes the three years in a row that La Nia impacted the patterns of the entire world’s climate, including worldwide drought and flooding.
The World Meteorological Organization (WMO) reported on Wednesday that recent trade winds increase had intensified La Nia conditions in the eastern and central equatorial Pacific. The WMO projects that the present La Nia trend will persist over the next six months, with a probability of 70% from September to November 2022 to a probability of 55% from December to February 2022-2023. In September 2020, the current La Nia pattern started.
There have only been two instances of a triple-dip La Nia since 1956, the most recent of which lasted from late summer 1998 to early spring 2001.
“Having a La Nina occurrence for three years is uncommon. In a news release, WMO Secretary-General Petteri Taalas stated that while its cooling effect is temporarily delaying the rise in global temperatures, the long-term warming trend will not be stopped or reversed. “La Nia is evident in the escalating drought in the Horn of Africa and southern South America, as well as the region’s above-average rainfall. Unfortunately, the recent La Nia Update supports local climatic predictions that the catastrophic drought in the Horn of Africa will intensify and afflict millions of people.
The central and eastern equatorial Pacific Ocean experiences La Nia, a natural and cyclical cooling of ocean surface temperatures. Along with the cooling, there are modifications to the tropical atmospheric circulation, specifically in the form of winds, barometric pressure, and rainfall. This cooling does not indicate a slowing of global warming. During La Nia episodes, trade winds are often more significant than usual, pushing warmer water into Asia.
The WMO claims that recent scientific advancements have increased our comprehension and forecast abilities within one to nine months in advance. Thanks to these alerts, countries can better plan for linked risks, including heavy rainfall, floods, and drought.
“WMO will continue to support sensitive areas including agriculture, food security, health, and disaster risk reduction” was Taalas’s assurance. “WMO will continue to give targeted information to the humanitarian sector.” The WMO is working toward the objective that everyone should have access to early warning systems in the coming years to protect them from threats related to our weather, climate, and water.
Off the western coast of America, upwelling is intensifying, bringing cold, nutrient-rich water to the surface. The Pacific Ocean’s colder surface waters drive the jet stream north, causing heavy rainfall and flooding in the Pacific Northwest and Canada while causing drought conditions in the southern United States. A La Nia year has winter temperatures that are warmer in the South and colder in the North, and the weather phenomenon can also result in a more active hurricane season.
The trade winds deteriorate, and warm water is pushed toward the west coast of the Americas when there is an El Nio, which has the opposite effect on global weather patterns. As the Pacific jet stream flows South, it causes wetter conditions in the Southeast and Gulf Coast while making it dryer and warmer than typical in parts of the northern US and Canada.
Serious La Nina Effects
- dry and droughty conditions
El Nia, the antithesis of El Nio, causes drought and dry conditions on the eastern rather than the western side of the equatorial Pacific. The coastal regions of Peru and Chile are affected mainly by dry spells and droughts, which could lead to subpar crop production. Due to a change in the global wind cycle circulation in the equatorial Pacific, the regular wind cycles that bring rain are now in the other direction, resulting in these conditions.
- Flooding and Prolonged Rain
As ocean temperatures fall off toward the east due to the changes brought about by La Nia circumstances after El Nio, the ensuing rainy weather patterns in the oceans result in torrential rains and floods that may linger for extended periods. La Nia is linked to the central Andes’ (South America’s) above-average rainfall, which frequently results in disastrous flooding. The La Nina also significantly determines extremely high rains and flooding in the Philippines, Brazil, Malaysia, and Indonesia.
- Typhoons, hurricanes, and freezing weather frequently occur.
When a La Nia occurrence occurs, the trade winds tend to get stronger, leading to more severe typhoons, hurricanes, and freezing weather worldwide. The development of powerful tropical cyclones in Asia that increase the risk of landfall in China is associated with the westward movements of the western Pacific Ocean caused by the La Nia.