- NASA Earth Observatory image by Kathryn Hansen, using VIIRS data from LANCE/EOSDIS Rapid Response
- In 2018, we’ve seen three named storms form early in the Atlantic, including Hurricane Chris and Hurricane Beryl.
- But unlike last year, it’s looking like this might be a relatively calm Atlantic hurricane season.
- That’s because ocean temperatures are cool, an El Niño might form in the Pacific, and there’s a lot of Saharan dust in the air.
Earlier in the year, there were some signs that we could be in for another intense Atlantic hurricane season.
Initial projections pegged the season as being likely to have slightly more storms than average – though 2017’s “extremely active” hurricane season began with a similar forecast.
Yet early signs of activity aside, projections for the rest of the hurricane season are changing, with experts now projecting a year that’s average or even below average in terms of activity.
First, a named storm, Subtropical Storm Alberto, showed up in May, a few days before hurricane season even officially kicked off.
Hurricanes Beryl and Chris both formed by July 10, the fourth time there had been two hurricanes by that date in the satellite era (since 1966). Beryl threatened Caribbean islands still recovering from hurricanes like Irma and Maria. Chris formed off the coast of the US, whipping up strong surf.
Chris had the lowest pressure – a measure of a storm’s intensity – for an Atlantic hurricane this early in the season since 2010’s Hurricane Alex, Colorado State University (CSU) meteorologist Philip Kotzbach said on Twitter. As Kotzbach also noted, this was the first time since 1906 that a storm as strong as Chris was so far north by this time of year.
Conditions around the globe, in the Atlantic, Caribbean, Pacifc, and in the winds from North Africa, all provide reason to think this year’s hurricane season will be less stormy than last year’s.
- REUTERS/Carlos Garcia Rawlins
What makes a hurricane season
An average hurricane season is based on the 30-year average from 1981 to 2010. By that definition, an average season includes 12 named storms and six hurricanes, with three of those being major hurricanes – storms that qualify as category 3 or higher on the Saffir-Simpson scale.
CSU’s newest forecast projects four hurricanes and ten named storms, with one being a major hurricane. If you average the predictions from major research institutions, government agencies, and universities, the mean prediction is six hurricanes, which would make this an average Atlantic season.
Hurricanes in the Atlantic are formed by a confluence of global conditions, including ocean temperatures in both the Atlantic and the Pacific (which can affect winds), long-term ocean currents, and atmospheric winds.
Right now, the tropical and subtropical Atlantic are abnormally cool, which favors less storm activity since tropical cyclones derive energy from warm waters.
A weak El Niño is also looking like it may form in the Pacific, meaning waters there could be slightly warmer than normal. That can create wind shear in the Atlantic, which tears apart hurricanes before they form. Caribbean trade winds are also quite strong right now, which can indicate a quiet season, according to Klotzbach.
The final factor that’s dampening storms right now comes from Africa. A lot of Saharan dust is being kicked up by winds and carried across the Atlantic, according to NASA. This dust can suppress storms before they form or intensify.
Anyone who experienced the 2017 hurricane season in the Atlantic is hoping for a quiet season this year. But just one storm is all it takes to do damage to a populated area.