(Bloomberg) -- After three straight winters, the weather-roiling La Nina has come to an end.
A cooling of waters in the equatorial Pacific has given way to more normal temperatures, signaling an end to the phenomenon that brought drought to California and South America and floods to Australia, the US Climate Prediction Center said Thursday in its final La Nina advisory.
“La Nina is over,” Michelle L’Heureux, a meteorologist at the center, said in a phone interview. “It is typical that the ocean goes first and then the atmosphere follows behind.”
With its end, the Pacific’s influence on global weather will pause, though L’Heureux said there could still be lingering effects in the atmosphere for a few more weeks as ocean waters return to more normal temperatures.
La Nina has held sway across the last three Northern Hemisphere winters, which is only the third time that has happened since 1950. The phenomenon has been blamed for ongoing drought across California because it often sends storms away from the state. La Nina is also known to minimize snowfall in US East Coast cities and bring more rains across northern Australia and Indonesia.
El Nino
With La Nina over, there is now a chance the Pacific Ocean surface could warm later this year and spark what is called El Nino. El Nino also upsets global weather patterns, though in different ways than La Nina. The pattern can lead to more winter storms across the southern US and milder conditions in the Pacific Northwest, along with dry and hot conditions across Australia and heavier rain in Argentina.
Climate forecasters estimate a 61% chance that El Nino could rise in the Pacific between August and October — little changed from the prior monthly forecast. L’Heureux said there is hesitancy among forecasters to get behind such an outlook, since climate models for La Nina and El Nino in March and April tend to be less accurate. Meteorologists call this the “spring barrier” since there isn’t a consensus on what will happen in six months.
El Nino during the Northern Hemisphere’s late summer would increase wind shear across the Atlantic, which would help destroy budding tropical systems and weaken those that are able to form. That would cut into the overall number of hurricanes, reducing chances of a devastating strike in the Caribbean, Mexico or the US.
Atlantic hurricanes are closely watched because of their impact on natural gas, oil and agriculture markets, as well as the large numbers of people who live along the Gulf of Mexico coast and the US Eastern Seaboard.
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