A peculiar warm water anomaly in the western Pacific is influencing this year’s anticipated “strong” El Niño in unexpected ways, according to reports by The Washington Post. The warm blob, situated in the west-central Pacific near the International Dateline, is defying typical El Niño behavior, as revealed by atmospheric science professor Paul Roundy from the University of Albany.
Conventional El Niño events induce warming in the eastern tropical Pacific, shaping atmospheric conditions globally. However, this year’s El Niño is deviating from the norm, prompting meteorologist Todd Crawford to observe on Nov. 8 that the atmospheric response “looks nothing like other recent strong El Niño events.”
Experts note that during usual El Niño years, warm waters in the eastern tropical Pacific cause air to rise, creating low-pressure conditions associated with showers and thunderstorms. Strikingly, the warm blob in the western Pacific is altering this pattern, causing increased tropical rain in that region. This, in turn, reduces rainfall intensity farther east, drying the atmosphere as the rising air subsides.
The anomaly in El Niño’s behavior this year is attributed to the lingering effects of a rare “triple dip” of La Niña events, El Niño’s cold counterpart. La Niña’s sustained cooling effect over the equator and eastern tropical Pacific in the past three years may still be influencing the current El Niño. Additionally, human-induced climate change may be contributing to the unusual warmth in the western Pacific.
The National Weather Service predicts that strong El Niño conditions could persist through the Northern Hemisphere winter until spring 2024, with a 35% chance of it becoming “historically strong” from November to January. While the warm blob challenges the typical El Niño winters, characterized by warm air masses in the north and cooler, wetter conditions in the south, experts suggest that normal El Niño signals might re-emerge.
Professor Roundy anticipates a decline in the interference caused by the warm blob, emphasizing the possibility of heavier rainfall to the east of the International Dateline. Additionally, westerly winds could push warm water away, exposing cooler layers underneath and encouraging a return to more traditional strong El Niño patterns this winter.
