I have been watching Atlantic tropical cyclones closely since 1971. In fact, when I was a teenager, my best friend and I used to make our our pre-season storm by storm forecasts. Of course, those forecasts were based on climatology. And one of the unwritten rules was “June too soon” for storms coming out of the maind development region of the Atlantic between the islands and Africa. August maybe, but not June.
We would have busted those forecasts this season. Not only do we have a strengthening tropical storm several hundred miles east of the Lesser Antilles, we have a second system right behind it that has a high probability of becoming a tropical depression today or tomorrow.
Tropical Storm Bret will pass through the Lesser Antilles Thursday evening. The center is forecast to pass near the islands of Dominica,, Martinique, and St. Lucia. Around 6 p.m. CDT Thursday. Tropical storm force winds could impact St. Vincent and the Grenadines, Barbados, and Guadeloupe based on the forecast track and average errors.
Bret could strengthen a little further today and tomorrow. There is good outflow evident on satellite imagery, but some wind shear is evident as well and mid-level dry air will also eventually inhibit development as it moves along its forecast path.
Tropical Storm Bret will weaken after passing into the eastern Caribbean, which is typical early in the season because of persistent shear. There are two troughs over the Caribbean that will cause sufficient shear to cause Bret to dissipate by Day Four or Five, which is Saturday or Sunday.
Hurricane Hunters are enroute to the storm and we will have a more accurate portrayal of its intensity and wind field. They took off from St. Croix around 930 a.m. CDT and should be on station by 12:30 p.m. CDT.
Meanwhile, Invest 93L is trailing behind Bret and is also expected to become a tropical depression later today or tomorrow. It should be a tropical storm by Friday and will become Cindy. The models seems to be in pretty good agreement that this system will find that developing weakness in the upper ridge to the north and will recurve through it, missing the islands and passing just east of Bermuda by late in the weekend. It is apparently no threat to the U.S. Mainland at this time.
Finally, there is another strong wave that has moved off the coast of Africa. It will also bear watching.
