By Kimberly Miller From Weather Plus

The chances that the global weather pattern christened La Niña will take hold by early fall were increased last week to 70 percent, foreshadowing a hurricane season that for the first time in years is expected to be something other than below-average.

With El Niño in its death throes, Florida is losing its hurricane bodyguard, and like a climatological Rip Van Winkle, La Niña is expected to be fully awake by the peak of storm season in September.

This year’s hurricane prediction from Colorado State University is for 13 named storms and six hurricanes, including January’s Hurricane Alex. AccuWeather is forecasting 14 named storms with eight hurricanes.

“I think our prediction is a little more aggressive this year because of La Niña,” said Phil Klotzbach, a hurricane researcher and lead author of CSU’s annual forecast. “The Atlantic is such a mixed bag right now, and there are a lot of factors to consider.”

During El Niño, water across the eastern path of the Pacific Ocean warms, making radical shifts to rainfall patterns. Showers are suppressed over Indonesia and moved to the eastern part of the Pacific. There, strong thunderstorms form, which influence wind patterns in the upper atmosphere, reducing wind shear in the Pacific and increasing it in the Atlantic.

Westerly wind shear in the Atlantic works to tear apart hurricanes as they develop.

With La Niña, waters in the Pacific cool, rainfall retreats to the west and the westerly winds wane – leaving the Atlantic and U.S. vulnerable to tropical cyclones.

The National Oceanic and Atmospheric Administration upped its La Niña chances after early April temperatures in the Pacific continued to cool. One of the main ocean areas where temperatures are measured is less than 1 degrees Celsius above normal.

That’s the first time it’s been that cool since mid-August, according to Klotzbach.

IMAGE: (05/08/2015) — This image of Tropical Storm Anna taken from the International Space Station displays the view looking south-southeastward from western Virginia towards storm about 200 miles east of Savannah, Georgia, Bahamas and Florida in the distance. Expedition 43 NASA astronaut Scott Kelly and his crewmates captured many images of the Earth showing the storms progression onto the Carolina’s and other east coast states.
(05/08/2015) — This image of Tropical Storm Anna taken from the International Space Station displays the view looking south-southeastward from western Virginia towards storm about 200 miles east of Savannah, Georgia, Bahamas and Florida in the distance.
An average season has 12 named storms and six hurricanes.

For more on this story go to:  http://weatherplus.blog.palmbeachpost.com/2016/04/18/chances-of-la-nina-increase-as-2016-hurricane-season-approaches/