As peak hurricane season gets underway, there is a unique reason to hope that South Florida dodges any storms.
According to forecasters at the National Center for Atmospheric Research, an El Niño combined with cool water should fend off escalation in the tropics.
Chris Davis, a senior scientist and associate director at the National Center for Atmospheric Research, says, “We’ve had five storms and nobody would probably guess that because none of them have been very significant. The development’s been pushed to the margins and hasn’t had time to organize into anything intense.”
Phil Klotzbach, a hurricane researcher at Colorado State University, adds, “The storms that have formed are different than what we saw last year. They are pretty classic of what we see with junk seasons.”
The peak of hurricane season goes from mid-August through mid-October, when about 95 percent of hurricanes form due to tropical waves spinning off the African coast.
Last year, Hurricane Franklin formed on August 9, followed by three storms of category 3 strength or higher — Harvey, Irma, Jose, Lee, Maria, and Ophelia.
Harvey, Irma and Maria made landfalls in Texas, Florida and Puerto Rico, respectively. Of those storms, Irma moved away from the coast of Africa as a tropical wave on August 27. It became a hurricane just four days later.
Early forecasts for the 2018 season predicted an average to above average season, but a change in oceanic conditions has reduced that forecast.
Specifically, a clockwise spin of winds that moves toward Bermuda during summer and the Azores during winter, or a “Bermuda High,” has resulted in stronger trade winds in the eastern tropical Atlantic. In turn, those winds are increasing the upswell in the ocean, which replaces warm water at the surface with cooler water from below, helping to keep storms away from land.
Klotzbach says this year’s sea surface temperatures are some of the coldest since the 1990s.
The current increase in Saharan dust is also reflecting solar energy back into the atmosphere, cooling the waters and drying the air even more.
However, the experts caution that quiet seasons can change suddenly if such trends as the Bermuda High remain strong and end up actually pushing storms toward the U.S.
Klotzbach warns, “Don’t let your guard down because the next 4 to 5 weeks are really important for Floridians.”