Signs continue to point to an above-average 2021 Atlantic hurricane season, with the tropical meteorology team at Colorado State University, in a report update issued Thursday, increasing the number of storms it expects to develop this year.
In its April 8 forecast, the CSU Tropical Meteorology Project predicted 17 total storms, including eight hurricanes, four of which were expected to be major hurricanes. On June 3, the team’s forecast raised the ante to 18 total named storms, including Ana, which formed in May. Of those, the meteorology team continued to predict eight hurricanes, four of which would be Category 3 or higher on the Saffir/Simpson scale.
But now the storm watchers from the Rocky Mountains have upped their prediction to 20 named storms, nine of which will become hurricanes and four of those will become major storms.
The development and intensification of Elsa into a hurricane in the tropical Atlantic also portends an active season, the CSU report said.
Elsa was designated a tropical storm on July 1, making it the earliest a season’s fifth named storm was designated since satellites began tracking the storms in 1966. The record had been held by Edouard, which developed a year ago on the evening of July 5.
The forecasters reminded coastal residents that the number of storms is not the only factor in how a hurricane season plays out.
“As is the case with all hurricane seasons, coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them. They should prepare the same for every season, regardless of how much activity is predicted,” the report said.
The Atlantic basin is quiet following the passage of Elsa, with no systems forming and nothing expected to develop for at least the next 48 hours. But conditions are still ripe for an active season, the CSU team surmised.
“Sea surface temperatures averaged across most of the tropical Atlantic are now near to slightly above normal, and most of the subtropical North Atlantic remains warmer than normal,” according to the report. “Elsa’s development and intensification into a hurricane in the tropical Atlantic also typically portends an active season. We anticipate an above-normal probability for major hurricanes making landfall along the continental United States coastline and in the Caribbean.”
Unlike the 2020 hurricane season, 2021 may bring a lot of long-tracked, classic Cape Verde-type storms. This is supported by the Intertropical Convergence Zone that is oriented from southwest to northeast and which leads to tropical disturbances pushing further south in latitude. The low latitude weather systems find themselves in an environment that is quite favorable for development as the hurricane season progresses.
“There is a good possibility that we may have the type of numbers of named storms we had in 2020, but with the destruction and chaos that was witnessed in the 2017 hurricane season,” the forecasters wrote. “It is beyond unusual to have a hurricane in the Windward Islands at the very beginning of July. That alone says that we have a much more favorable background state than average for tropical development across the Atlantic Basin. This is a huge red flag for the peak part of the season. In an average season, Elsa would have never developed where it did.”
Make a plan and be prepared, the report urges residents.
“Then, buckle up as, unfortunately, we may be in for another very active and potentially very destructive hurricane season.”