Forecasters are monitoring the development of one and potentially two tropical systems over what have been record warm waters between the Caribbean and West Africa, and the National Hurricane Center is forecasting the first will more than likely grow into Hurricane Bret.
That first system became a tropical storm Monday with sustained winds close to 40 mph, the center said. Tropical Storm Bret is predicted to bulk up to hurricane strength within a few days.
The appearance of the two systems in June is unusual, and abnormally warm water is expected to play a major role as this year’s hurricane season unfolds.
“We just happen to have gotten two separate waves that have come out at the right latitude they need to be for June development,” said David Roth, a forecaster for the National Oceanic and Atmospheric Administration’s Weather Prediction Center in College Park, Maryland.
Where are the systems now?
Bret was churning about halfway between Africa and the Lesser Antilles, the string of Caribbean islands that includes the nations of Saint Lucia, Trinidad and Tobago, Barbados and Grenada. Late Monday, the National Hurricane Center predicted the storm will develop into a hurricane of Category 1 strength with winds of 74 mph by Wednesday night and could potentially hit the islands within several days.
“It could go through the central Caribbean or miss it entirely,” Roth said.
The second system is about 750 miles behind the first one, Roth said, and, while it appears unlikely to reach land, conditions are more favorable than normal for it to similarly develop into a legitimate storm, given the warm waters and a lack of strong vertical wind shear to hack through the system.
“It has a 40% chance of becoming a tropical cyclone,” Roth said. “It’s showing some organization, walking the tightrope really well. We have a favorable pattern where there usually isn’t.”
Should the distance close between the two systems – to about 500 miles – it’s possible the pair could merge as one absorbs the other, he said.
How rare are these storms in June?
Ocean waters in the prime breeding area for major hurricanes, a strip of ocean referred to as the Main Development Region, have posted record-warm temperatures for mid-June.
“We can squabble over what’s behind the rapid Atlantic warming, but it’s truly extraordinary to see waters in the Main Development Region of the tropics as warm in June as they typically are the first week of September,” hurricane expert Michael Lowry posted on Twitter, predicting the condition would be “an undeniably big player this hurricane season.”
According to AccuWeather, such tropical systems in this portion of the Atlantic basin don’t typically show up until August or September. And while their development in June is not unheard of, Roth said, “it’s not an every-year thing. Now – if we were to get two of them, that would raise my eyebrows a bit.”
In fact, two tropical storms in June would be unprecedented for the region, according to Weather.com, noting that the month accounts for only about 6% of all storms, mostly in the Gulf of Mexico or just off the East Coast. Only three of 79 June storms since the 19th century have formed east of the Lesser Antilles – two of them in the past six years.