Mississippi keeps eye on Tropical Storm Bret, which could become first hurricane of season
Published 6:02 am Tuesday, June 20, 2023
Residents in Mississippi and other Gulf Coast states are keeping a wary eye on Tropical Storm Bret which formed over the central Atlantic Ocean on Monday and will begin to enter the warm waters of the eastern Caribbean, headed toward the Gulf.
The National Hurricane Center named Bret, which was spinning about halfway between Africa and the Lesser Antilles, at 5 p.m. EDT Monday. The system had maximum sustained winds of 40 mph and was moving west at 21 mph.
Satellite images taken on Monday afternoon revealed a healthy and strengthening tropical system.
As of 5 a.m. EDT Tuesday, Bret continued to have maximum sustained winds of 40 mph, but its westward movement had slowed to 17 mph.
The storm was named Bret once its maximum sustained winds reached 39 mph and it displayed an organized center of circulation.
It is not out of the question that the system could strengthen enough to become the first hurricane of the 2023 season in the Atlantic prior to nearing the eastern Caribbean.
This is unusually early for a tropical system to form in this part of the basin from a tropical wave that emerged from Africa. Typically, these Cabo Verde systems, as meteorologists refer to them, develop during the heart of the season from August through September.
“While it is rare to get a storm to develop over the south-central Atlantic in June, it is not completely unheard of,” AccuWeather Tropical Meteorologist Alex DaSilva said on June 15. There have been only a half-dozen or fewer tropical systems to develop in this zone over the past 25 years in June.
Currently, the ocean water temperatures from the Cabo Verde Islands to the Windward Islands range between 80 and 82 F, or 27 and 28 C, at the surface. Compared to typical mid-June sea surface temperatures, values observed this week are trending several degrees higher than the historical average. The approximate minimum threshold for tropical development is 80 F (26 C).
An important factor that has allowed the sun’s rays to warm the Atlantic waters quicker than in previous years is the reduced amount of Saharan dust. An abundance of Saharan dust in the atmosphere across the Atlantic basin can be a limiting factor in suppressing tropical formation. It will result in a very dry air mass overhead and reduces the sun’s energy reaching the ocean’s surface.
“Not only are water temperatures above the minimum threshold for tropical development, but the atmospheric environment the system is moving into has plenty of hot air as well,” AccuWeather Senior Meteorologist Alex Sosnowski said. “These factors are likely to allow the system to strengthen further and perhaps to a hurricane.”
During its westward trek across the Atlantic waters, forecasters say that the tropical system will encounter varying levels of wind shear.
“Currently, this feature is in a pocket of low wind shear, which helps to create an environment conducive to development and strengthening,” explained DaSilva. If wind shear increases along the path, then it may halt or slow the strengthening process.
Wind shear is the change in direction and speed of winds throughout the various levels of the atmosphere. It can critically influence how vertically stacked and organized a storm can become. As a tropical feature becomes more vertically stacked, it can strengthen and become more organized over the warm ocean waters. Strong vertical wind shear is typically bad news for tropical elements, as it can rip apart the layers stacked throughout the atmosphere.