Tropical Storm Bret has gained some strength today over the central tropical Atlantic, and is likely near its peak intensity as it is expected to pass through the Lesser Antilles tomorrow evening. Tropical Storm Watches and Warnings have been issued for much of the region. In addition to Bret, Invest 93L over the eastern tropical Atlantic appears to be on the cusp of becoming a tropical depression, and will likely develop tomorrow.

As of 5:00 p.m. EDT Wednesday, Tropical Storm Bret was centered near 13.3°N 53.9°W, and was moving westward at approximately 15 mph. Maximum sustained winds were 55 knots (65 mph), with an estimated minimum pressure of 1000 mb. There is now a much clearer idea of Bret’s intensity now that a reconnaissance aircraft has sampled the storm, and the data proved the National Hurricane Center (NHC’s) estimate was very accurate. Bret’s intensity of 55 knots (65 mph) makes it the strongest tropical cyclone by wind speed in the tropical Atlantic east of the Lesser Antilles during June in the satellite era. Although Bret has strengthened since yesterday and is moving over sea surface temperatures warmer than 28°C (82.4°F), the cyclone has been unable to develop a well-defined inner core due to persistent mid-level shear. This mid-level shear is expected to persist throughout the next 24 hours or so, but some slight additional intensification cannot be ruled out. After that time, the deep-layer vertical wind shear is expected to increase to around 30 knots, which should quickly cause Bret to weaken and eventually dissipate over the eastern or central Caribbean Sea by Saturday. A Tropical Storm Warning is currently in effect for St. Lucia and Martinique, while a Tropical Storm Watch is currently in effect for Barbados, Dominica, St. Vincent and the Grenadines. Interests in the Lesser Antilles should be prepared for Tropical Storm Conditions Thursday evening and night.

A tropical wave, numbered Invest 93L by the NHC, has gradually become better organized over the past few days and is close to becoming a tropical depression. The NHC currently gives 93L a 70 percent chance of development within 48 hours, and an 80 percent chance within 7 days. 93L has struggled to maintain persistent deep convection, but an ASCAT pass from this morning suggested that an elongated low-level circulation has developed. If 93L becomes a Tropical Storm, it would be named Cindy. Some easterly shear has limited development of 93L so far, but this shear is expected to lessen tonight, which should allow a window for some slight development. In about 72 hours or so, vertical wind shear is expected to increase to greater than 20 knots, which should limit development after that time and may even cause 93L to dissipate. While it currently appears likely 93L will turn northwest without affecting the Lesser Antilles, interests in the northern Leeward Islands should monitor 93L in case the forecast changes.