The 2018 hurricane season is almost upon us, and meteorologists are predicting it may be as busy as 2017.
The National Oceanic and Atmospheric Administration (NOAA) is "forecasting a 75-percent chance that the 2018 Atlantic hurricane season will be near- or above-normal."
“With the advances made in hardware and computing over the course of the last year, the ability of NOAA scientists to both predict the path of storms and warn Americans who may find themselves in harm’s way is unprecedented,” said Secretary of Commerce Wilbur Ross on NOAA's website. “The devastating hurricane season of 2017 demonstrated the necessity for prompt and accurate hurricane forecasts.”
NOAA predicts there will be 10 to 16 named storms, of which five to nine could become hurricanes.
Colorado State University also released its 2018 forecast for the Atlantic hurricane season on April 5, which falls in line with NOAA. Their forecast calls for 14 named storms; seven of those storms are predicted to become full-fledged hurricanes and three of those are predicted to be major hurricanes. Any hurricane that is a Category 3 or higher is considered a major hurricane.
CSU's forecast also says there's a "slightly above-average probability for major hurricanes making landfall along the continental United States coastline and in the Caribbean" this year. While that's never good news, it's especially bad news for islands in the Caribbean like Puerto Rico, the U.S. territory that's still recovering from the devastation caused by Hurricane Maria. (The photo above shows the island in October 2017, with power lines and palm trees flattened.)
How do they make their predictions?
The meteorologists behind the forecast rely on a variety of factors when making their predictions, but the two primary ones are whether or not El Niño develops in the Pacific Ocean and the sea surface temperatures of the North Atlantic.
El Niño brings with it warm sea surface temperatures in the Pacific, and that leads to stronger winds in the mid-levels of the atmosphere. These stronger winds limit the formation and strength of tropical storms in the Atlantic. El Niña is the reverse of that. Currently, computer models are predicting that neither of the cycles will form this year, leading to "neutral conditions," according to The Washington Post.
This combination makes North Atlantic sea surface temperatures the key predictor of the hurricane season — at least for now. The western North Atlantic is warmer than usual right now, but temperatures are cooler in the far North Atlantic and in the eastern North Atlantic, thanks in part to strong winds in January and February. These cooler temperatures would mean a less significant hurricane season, but sea surface temperatures were this way last year, too, and by late spring and into summer, water temperatures had risen quickly, giving fuel to hurricanes last year, notably Irma, Jose and Maria.
Several models are predicting that this scenario will play out again, with sea surface temperatures spiking from August to October, resulting in "a somewhat active season."
According to a new study, the magnitude of rapid intensification — when a hurricane intensifies by 25 knots or higher in a 24 hour period — has increased over the past 30 years. Major hurricanes today are traveling 13mph faster on average, and researchers say a lot of that has to do with Atlantic Multidecadal Oscillation (long periods of times when sea surface temperature changes).
Hurricane season runs from June to November, typically, but storms have been known to form earlier. Last year, tropical storm Arlene formed in mid-April.
Related on MNN: How hurricanes are named (and why)
Editor's note: This article has been updated since it was originally published in April 2018.