La Niña weakening, neutral Pacific conditions likely by April: US

The La Niña exerting its influence on global weather since last year is forecast to fizzle out in the coming months, returning the Pacific Ocean to its neutral state sometime in April.

 

The Pacific is expected to remain normal through summer in the Northern Hemisphere, according to the US Climate Prediction Center. 

 

La Niña, which forms when the equatorial Pacific cools and the atmosphere reacts to it, typically wanes after its December-to-January peak. Climate center scientists are already seeing signs of decreasing strength in warmer ocean water and a weakening in atmospheric changes, the agency said in a statement. La Niñas typically mean colder winters across the northern US, which has been the case this year.

 

 

Neutral conditions may eventually change to El Niño, when the Pacific warms, between September and November. This would be a big development for Atlantic hurricanes because El Niños increase storm-destroying wind shear across the Caribbean. That wind shear typically brings some reprieve to the six-month hurricane season, which starts June 1. El Niños have virtually stopped storm development in the western Atlantic many times in recent years.

 

Powerful Atlantic hurricanes can disrupt down oil and gas production in the Gulf of Mexico, kill hundreds and leave billions of dollars in damage in their wake. Last October, Hurricane Melissa struck Jamaica as a record-breaking Category 5 storm on the five-step, Saffir-Simpson scale, killing at least 33 people and causing almost $8 billion in damage across multiple islands in the Caribbean.

 

Even with these early indicators, there’s one caveat. During a span known as the “spring barrier,” forecasts for the Pacific can be highly speculative and don’t start improving until around June. “Model uncertainty remains considerable, and forecasts made this time of year tend to have lower accuracy,” according to the climate center. 

 

As neutral conditions are forecast through April to at least September, there is little chance the Pacific will play a dominant role with weather patterns across the Northern Hemisphere’s summer.