Early September is typically the peak of hurricane season in the Atlantic basin, but it’s been fairly quiet so far.
(We know. We used the “q” word. Imagine us knocking on wood.)
But based on the activity (or lack of it) that we’ve seen so far, forecasters from NOAA’s National Weather Service shared an updated prediction for the season, and it’s even lower than it was before June 1.
NOAA now expects only 7-13 named storms (with winds of 39 mph or greater), of which 2-6 could become hurricanes (winds of 74 mph or greater), including 0-2 major hurricanes (winds of 111 mph or greater).
So NOAA is saying there’s a chance we could see only a handful of hurricanes, and it’s possible none of them will reach Category 3 or greater.
Also, those numbers include the two tropical storms (Arthur and Bertha) that already formed this season.
Breaking it down pie-chart style, NOAA forecasters predict a 75% chance for below-normal activity, with a 20% chance of a near-normal season, and just a 5% chance of above-normal activity.
This updated prediction is similar to the initial outlook issued in May.
In the Atlantic basin, a typical hurricane season will yield 14 named storms, of which seven become hurricanes, including three major hurricanes.
Only Gulf storms so far
Tropical Storm Arthur was the first named storm of the Atlantic season.
Forming in mid-June in the warm Gulf waters off the Texas coast, Arthur brought record rainfall to portions of Louisiana and spawned tornadoes along the Gulf coast.
Bertha also formed in the Gulf, originating south of the Florida panhandle before making landfall in St. Bernard Parish, Louisiana.
“Inland rainfall is a major cause of damage from tropical storms and hurricanes, as Arthur demonstrated,” said NOAA’s National Weather Service Director Ken Graham. “That’s why it’s important to prepare for every storm that’s projected to impact your area, even if it never reaches hurricane strength.”
Factors influencing the season outlook
For the remainder of the season, tropical storm activity in the Atlantic basin is expected to be tempered by El Niño conditions, which first emerged in the equatorial Pacific in June.
El Niño increases wind shear, which tends to prevent tropical storms from forming or from getting stronger once formed.
Other less influential factors include temperatures near average in the Atlantic Ocean and a neutral west African monsoon.
“When El Niño emerges, it usually becomes the dominant factor in total hurricane season activity, and this El Niño continues to get stronger every month,” said Matt Rosencrans, lead hurricane season forecaster with NOAA’s National Weather Service. “Compared to a mature El Niño, other mechanisms play a smaller role in determining the number and intensity of tropical storms in the Atlantic basin.”