A certain quiet has fallen over the Atlantic Ocean the past few years, and meteorologists are anticipating another calm hurricane season in 2017.
On Thursday, Colorado State University, which has prepared forecasts for nearly three decades, predicted another below-average hurricane season, which runs from June through November. During that span, they expect 11 named storms, of which four will strengthen to hurricane level and two will reach Category 3 or higher — "major hurricane" status.
Lead author Phil Klotzbach expects two factors to determine the weather. In the past few weeks, he said, windy seas and sunlight-blocking sand from the Sahara Desert have caused the Atlantic's temperature to drop, making it less conducive to hurricane formation.
If the water stays cool, early summer should stay relatively peaceful. However, more than nine out of ten major storms form in August or later. To keep those at bay, meteorologists are expecting some help from El Niño.
The Colorado State team is predicting a weak or moderate El Niño effect this year. The weather system causes warmer ocean temperatures in the Pacific and winds in the Atlantic that shred tropical storms before they can coalesce into hurricanes, according to the National Oceanic and Atmospheric Administration.
"El Niño really kills your late-season storms," Klotzbach explained.
Long-term forces of nature also come into play. The Atlantic cycles between periods of calm and chaos that can last 20 to 25 years. Powerful hurricanes hammered the coast in the 1990s and 2000s, but the past few years have generally been drier and more peaceful, Klotzbach said.
Nevertheless, NOAA is advising caution.
"We are now entering our 12th year without a major hurricane ... having hit the United States, (the last) being Wilma in October 2005. Our luck is going to run out. The farther we get from the last hurricane, the closer we get to the next one," warned meteorologist Dennis Feltgen of NOAA's National Hurricane Center.
And it doesn't take a "major" landfall to cause damage, as survivors of 2012's Hurricane Sandy can attest.
Last year, Hurricane Matthew sidled along the Florida coast at Category 3 strength but had weakened to Category 1 by the time it technically made landfall in South Carolina. It still caused 34 deaths and an estimated $10 billion dollars of damage in America, all after wrecking the Caribbean — especially Haiti, where it killed 546 people and destroyed "at least" 29,000 houses, according to a NOAA report.
Klotzbach said coastal residents should prepare any differently this year than they would any other year, even though the forecast is for a below-average hurricane season.
"You need to prepare the same every year," he said.
To come up with their annual forecast, the Colorado State team considers the upcoming climate conditions and creates a model using historical data. While American hurricane data predates the Civil War, it wasn't until the 1950s that data such as water temperature and barometric pressure readings became truly reliable, Klotzbach said.
The model helps meteorologists determine all the combined energy they expect all storms to generate during the hurricane season. This year, it's 20 percent less than average. Then, they take the total amount of storm power and consider how it will be distributed over the entire season, leading them to predict 11 named storms in 2017, including four hurricanes, a pair of which will be especially severe.
Some storms die over water, as happened last year to major hurricanes Gaston and Nicole. In 2017, Klotzbach's team predicts a 42 percent chance of a major hurricane striking the U.S., and a 24 percent chance of such a storm striking the Gulf Coast between Tampa and the Rio Grande.
Other entities will release their own forecasts as hurricane season approaches, including NOAA's Climate Prediction Center, where meteorologists were not available for comment Thursday but plan to publicize their own findings May 25.