On the heels of Hurricane Debby, AccuWeather hurricane experts are tracking the latest tropical rainstorm, designated Potential Tropical Cyclone 5 by the National Hurricane Center, across the central Atlantic Ocean, which could rapidly organize to become the basin’s next tropical storm or even major hurricane in the coming days as it sweeps through the Caribbean, bringing heavy rain, strong winds and rough surf into midweek.
Late Saturday, Aug. 10, AccuWeather initiated a forecast track map for this tropical rainstorm, highlighting the risk for impactful weather across the Caribbean and Bermuda. The current forecast shows this feature ramping up to a tropical storm (sustained winds of 39-73 mph on the Saffir-Simpson Hurricane Wind Scale) as early as Monday.
Once this feature reaches tropical-storm strength, it would claim the next name on the 2024 Atlantic Hurricane Season storm lineup, which is Ernesto.
By early this week, forecasters warn that this feature could ramp up to at least a Category 1 hurricane as it travels across the warm waters of the far northeastern Caribbean Sea and shifts north of Puerto Rico and Hispaniola. Sea-surface temperatures across this zone in the Atlantic are well above the minimum threshold required for tropical development (>26ºC, or 78.8ºF), currently reading between 28-30ºC (82.4-86ºF).
“Ocean temperatures across the Atlantic basin as a whole remain near-record levels, only trailing 2023 values,” explained AccuWeather Meteorologist and Lead Hurricane Expert Alex DaSilva.
Ocean Heat Content, a measure of how much energy and warmth is absorbed by the sun and takes into account the depth of how far that warm water extends vertically, is also at near-record levels in the Main Development Region. Not only are water levels anomalously warm at the surface, the elevated ocean temperatures extend hundreds of feet down below the oceans surface.
“Factors such as near-record ocean heat content levels can help to significantly contribute to the rapid intensification of hurricanes. Both Hurricane Beryl this year and Hurricane Ian in 2022 took advantage of very high sea-surface temperatures and ocean heat content, which allowed these storms to rapidly intensify as a result,” added DaSilva.
AccuWeather hurricane experts are putting areas of the Leeward Islands, Puerto Rico, Hispaniola and the Turks and Caicos Islands on alert for tropical impacts this week. This healthy tropical rainstorm charging across the warm waters of the central Atlantic will be the next notable feature in the wake of Debby to bring impacts to the western Atlantic.
This feature is projected to take on a general west-northwesterly track through at least the middle of this week; however, forecasters say that a crucial factor for whether or not locations in the western Bahamas, Florida and the remainder of the southeastern United States coast could feel impacts from this storm is dependent upon upper-level steering winds in the atmosphere.
Wind shear is forecast to be pretty light as the storm approaches and moves through the northeastern Caribbean Islands. After moving through the islands, the storm will likely be drawn to the north by an amplified southward dip in the jet stream.
“Currently, the weather along the southeastern U.S. coast looks fairly nice next weekend, so even if the storm remains well offshore, coastal impacts such as rough surf and rip currents could spell trouble for beach-goers trying to soak up the last weekends of summer,” explained AccuWeather Meteorologist Emma Belscher.
At this time, the tropical rainstorm is expected to veer northward and then slightly northeast by late week, potentially ramping up to a major hurricane (characterized as Category 3 or higher) for a time before setting its sites on Bermuda by the upcoming weekend.
Belscher added that while the storm is expected to journey towards Bermuda, if its takes a bit more of a southern track initially, it could be pushed closer the East Coast.
As this tropical rainstorm advances westward and scrapes the Leeward Islands early this week, it will produce rounds of rain across the region. The outer rainbands of the storm are expected to reach the Lesser Antilles later Monday before encompassing the Virgin Islands and Puerto Rico Monday night into Tuesday.
Heavy rain from this feature will pose the risk for flash flooding and mudslides across the islands, especially across the mountainous terrain. In general, tropical rainfall totals will range up to 2-4 inches across Guadeloupe, Antigua and Barbuda, Montserrat, St. Kitts and Nevis and Anguilla.
Farther west, into Puerto Rico and the Virgin Islands, totals can range much higher, between 4-8 inches. Rainfall amounts to this degree can lead to flooding, washouts, dangerous travel and mudslides across the eastern and northern Caribbean Islands.
Gusty winds are projected to ramp up early this week as the tropical feature barrels across the northeastern Caribbean Islands. Gusts can exceed 80 mph from the Lesser Antilles to Puerto Rico as the center of the storm passes through the region. Winds can even surpass 100 mph, primarily over water, if the storm strengthens and veers northward later in the week.
AccuWeather meteorologists insist that a super-charged Atlantic hurricane season will unfold this year, with a large number of tropical storms and hurricanes. Some storms are likely to undergo rapid intensification due largely to the ongoing higher-than-historical average water temperatures.