Tropical Storm Danny May Become a Hurricane Later This Week; Potential Threat to Lesser Antilles Next Week

August 19,2015

• Tropical Storm Danny was located about 1,385 miles east of the Windward Islands in the eastern Atlantic Ocean as of 11 a.m. EDT Wednesday.
• Maximum sustained winds were 50 mph with higher gusts.
• The tropical storm is forecast to steadily strengthen as it moves west-northwest over the next several days. Danny is forecast to become a hurricane later this week.
• It will be until early next week before Danny reaches the longitude of the Lesser Antilles.

Storm Stats and Satellite

Tropical storm Danny continues to spin about halfway between Africa and the Lesser Antilles in the eastern Atlantic Ocean. This is the first named storm in the Atlantic since the final advisory was written for Claudette on July 14, a time span of more than a month.

Danny is exhibiting a commahead appearance in satellite imagery as of late Wednesday morning. An early-morning microwave satellite image pass showed convection hasn't completely encircled the center of Danny's circulation.

(INTERACTIVE: Satellite Loop of Danny)

Water Vapor Image: Danny

Current Wind Shear Analysis

This may be due to some dry air being ingested by Danny. Dry air hampers tropical cyclones by encouraging the development of stronger thunderstorm downdrafts, which then either squelch nearby thunderstorms from forming or push them away.

This dry air is also stable, meaning it suppresses upward vertical columns of air needed to maintain or form new thunderstorms.

This will be a continual challenge to Danny over the next several days, as water vapor imagery indicates an ample reservoir of dry air north of Danny extending westward into the eastern Caribbean Sea.

Wind shear, namely, the change in wind speed with height either in speed and/or direction, can blow convection away from the center from a tropical cyclone. If strong enough, this can rip apart existing tropical cyclones.

Despite what had been a rather hostile atmosphere featuring record mid-July through mid-August Caribbean wind shear, Danny sits far south to remain in an environment of rather light wind shear.

So, assuming the atmosphere immediately surrounding Danny remains somewhat moist, Danny is forecast to strengthen to the first hurricane of the 2015 Atlantic hurricane season possibly as soon as Thursday night or Friday.

(MORE: Track Danny in Real-Time With Our New Interactive Storm Tracker)

The movement of this system will be to the west-northwest the next few days. Computer model forecast guidance shows that it may not reach the longitude near the eastern Caribbean Sea (about 60 degrees West longitude) until early next week.

Projected Path

As a result, we have plenty of time to monitor its progress.
Given the aforementioned dry air and wind shear in place over the eastern Caribbean Sea, it's possible that this system eventually weakens once it reaches the vicinity of the Lesser Antilles.
In summary, it's far too early to know if this system will bring any significant impacts to those islands in the long-term future. Interests in the Lesser Antilles, the Virgin Islands and Puerto Rico should monitor the progress of Danny.
(MORE: Satellite Maps)
Stay tuned to The Weather Channel and check back with weather.com for updates on this system.
(MORE: Heart of the Hurricane Season is Here)
Senior meteorologists Nick Wiltgen and Jonathan Erdman and meteorologist Chris Dolce contributed to this report.

MORE: Hurricanes by the Numbers