Tropical Storm Bret is forecast to strengthen into a hurricane as it approaches the eastern Caribbean’s Leeward and Windward islands, with meteorologists noting that the weather pattern is unusually early and aggressive for the Atlantic cyclone season that formally began on 1 June.
It is only the second hurricane to form in the tropical Atlantic in June since record keeping began, according to forecasters. The previous June hurricane was the 1933 Trinidad hurricane.
On Tuesday morning, the storm had maximum sustained winds of 40mph and was moving across the Atlantic Ocean at 17mph.
It is predicted to strengthen into a hurricane, hit the eastern Caribbean islands on Thursday and Friday, but then weaken ahead of its approach to the Lesser Antilles, potentially taking aim at southern Haiti as a tropical storm, according to the National Hurricane Center in Miami.
“Both the atmospheric and oceanic environment look conducive for strengthening during the next couple of days with low shear and abnormally warm ocean waters,” the center said.
Forecasters also warn of strong winds, dangerous storm surge and waves, and flooding from heavy rainfall. They also urged people in the Lesser Antilles and Puerto Rico to make emergency plans ahead of the storm’s arrival.
“Given the larger than usual uncertainty in the track forecast, it is too early to specify the location and magnitude of where these hazards could occur,” the center said.
Tropical Storm Bret is set to be followed by another weather pattern, currently listed as a disturbance, that has a 60% chance of cyclone formation. No June on record has had two storms form in the tropical Atlantic, according to meteorologist Philip Klotzbach at Colorado State University.
Last month, forecasters with the Climate Prediction Center at the National Oceanic and Atmospheric Administration (Noaa), a division of the National Weather Service, predicted near-normal hurricane activity in the Atlantic this year.
Noaa has forecast a range of 12 to 17 total named storms this Atlantic hurricane season, which ends after November. Of those, five to nine could become hurricanes, including one to four major hurricanes (categories 3, 4 or 5, with winds of 111 mph or higher). Noaa has a 70% confidence in these ranges.
After three hurricane seasons with La Niña present, Noaa scientists predict a high potential for unusually warm water in the Pacific ocean, or El Niño, to develop this summer. El Niño typically suppresses Atlantic hurricane activity but with a warming climate historical weather patterns are less predictable.
Noaa administrator Rick Spinrad said in a statement that the National Hurricane Center’s tropical weather outlook graphic, which shows tropical cyclone formation potential, has expanded the forecast range from five to seven days.
The weather prediction center also notes that over the last 10 years, flooding from tropical storm rainfall has become the single deadliest hazard and will now extend its excessive rainfall outlook from three days to five.
