The National Hurricane Center declared Tropical Storm Bret formed at 5 p.m. Monday, the second of the young Atlantic season. Located about halfway between the coast of Africa and the eastern Caribbean Sea, the system is likely to intensify, and it could approach or impact the Lesser Antilles as a hurricane by the weekend.

Bret is predicted to “move across the Lesser Antilles as a hurricane on Thursday and Friday, bringing a risk of flooding from heavy rainfall, hurricane-force winds, and dangerous storm surge and waves,” the National Hurricane Center said.

It added, “Everyone in the Lesser Antilles, Puerto Rico, and the Virgin Islands should closely monitor updates.” The Lesser Antilles includes the islands of Trinidad and Tobago, Barbados, Saint Lucia, and Grenada, among others.

For a storm to develop where Bret did during June is historic. In fact, it formed farther east than any tropical storm on record this early in the year. It also became one of the earliest named storms on record in the Atlantic’s Main Development Region. The MDR is the region between the Caribbean and Cabo Verde where long-lived, intense storms can grow out of disturbances rolling off the coast of Africa. Usually, storms don’t form in the MDR until around August.

While atmospheric chaos plants the seeds of storm growth, record-warm ocean temperatures over the Atlantic have created an environment ripe for this system’s intensification. Ocean temperatures around the world are at record-high levels, with human-caused climate change the driver of a long-term warming trend. The waters in the Atlantic are as warm as they would typically be at the peak of hurricane season two to three months from now.

The Hurricane Center is also monitoring a second disturbance in the wake of Bret that has a strong chance to develop into a storm as well.

As of 5 p.m. Monday, the center of Bret was located about 1,300 miles east of the southern Windward Islands, moving briskly west at 21 mph.

“Satellite imagery continues to show that the system is becoming better organized,” the Hurricane Center wrote.

Maximum sustained winds were listed at 40 mph.

The nascent storm exhibited healthy outflow, visible in the tendril-like wispy clouds fanning outward to the north. Outflow, or high-altitude exhaust, is integral to strengthening. The more “spent” air a storm can evacuate up and out of its fledgling center, the more warm, humid air from below it can inhale. That fosters further organization and strengthening.

Bret will be driven west, prevented from turning north in the short term by a blocking zone of high pressure over the central Atlantic. Low amounts of disruptive wind shear, or a change of wind speed/direction with strength, will allow it to intensify, perhaps into a Category 1 hurricane, by Wednesday.

If Bret strengthens more quickly than currently predicted, it would grow taller, and would be more prone to a northward curve before the end of the workweek. A taller storm would mimic a sailboat hoisting its sails, catching the wind and being blown in a given direction. However, weather models are more consistent in depicting Bret as continuing its trek due west, eventually affecting the Leeward Islands.

Historically, early-season storms are more likely to weaken in the Caribbean, and the Hurricane Center does predict a gradual decrease in its peak wind speeds after it passes the Lesser Antilles. But it cautioned model forecasts for Bret’s intensity vary considerably.

On average, the first Atlantic hurricane doesn’t form until Aug. 11.

How unusual is this? Simply stated, very.

Only four other named storms on record have formed in the MDR during the month of June; the earliest, coincidentally also named Bret, was named on June 18, 2017, but this latest rendition of Bret has earned its name farther east.

Exceptionally warm sea surface temperatures, up to 5 degrees above normal, are feeding the storm, and will probably contribute to a number of overachieving systems this hurricane season.

Another tropical wave several hundred miles southwest of the Cabo Verde Islands has a 50% chance of eventual development. Weather models also forecast this system will strengthen. If it earns a name, it will be called Cindy.

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