HERE COMES DANNY: Hurricane Danny on Path Toward Northern Caribbean

By Alex Sosnowski, AccuWeather.com Senior Meteorologist

August 22, 2015

Danny became the first hurricane of the 2015 Atlantic season this week and is now a Category 2 system.
Satellite imagery and aircraft reconnaissance reports suggested that Danny was a Category 3, major hurricane shortly past noon Eastern Daylight Time on Friday. The storm weakened to a Category 2 system late on Friday.
The system is currently on track to bring drenching rain to part of the northern Caribbean islands as a weakening system next week. However, there is the potential for the system to turn more to the northwest, which could allow it to survive.

Danny follows Ana, Bill and Claudette from earlier this season. None of the first three storms reached hurricane status.

Breaking: Danny Weakens, Kilo Expected to Strengthen

The system became a tropical depression on Tuesday morning, a tropical storm on Tuesday afternoon then a hurricane during Thursday morning, local time. Danny was upgraded to a Category 3 hurricane on Friday morning but is expected to slowly weaken through the weekend.

Satellite imagery of Hurricane Danny (Image/NOAA)
When sustained winds around the center of circulation reach 39 mph (63 kph), a tropical depression is upgraded to a tropical storm. For a system to become a hurricane, sustained winds must reach 74 mph (119 kph), which Danny's winds exceeded this Thursday morning.
The system is moving west-northwestward over the south-central Atlantic Ocean at 10-15 mph (15-25 kph).

As of 5 a.m. Saturday local time, Danny was about 740 miles east of the Leeward Islands.
According to AccuWeather Hurricane Expert Dan Kottlowski, great fluctuations in strength are likely through the time it reaches the Leeward Islands by Monday.
"The small, compact nature of Danny makes it a challenging storm to forecast as it can ramp up quickly, then weaken in a matter of hours," Kottlowski said.

Dry air from the north will occasionally wrap into the storm causing it to weaken.
"Despite the issues with dry air, the system will remain in an overall favorable area for development into the weekend with warm waters and weak wind shear," Kottlowski said.

Wind shear is when strong winds near the surface and aloft blow strongly from different directions.
Danny will likely continue to weaken this weekend, prior to reaching the Leeward Islands as it begins to run into increasing wind shear.
Danny is forecast to continue to move in a general west-northwest direction through next week, which will take the system across the northern islands of the Caribbean.
Occasionally, Danny will jog more to the northwest and other times will push more to the west. Before next week, a northwest jog is more likely to occur when the system is a hurricane.
"We have a concern that Danny may skip just north of the Antilles next week," Kottolowski said. "If this happens, there would not be as many reasons for the system to weaken and the chance of the system getting closer to the United States mainland would increase."
Danny is being guided along by the oval-shaped circulation of high pressure over the central Atlantic. By next week, the system will be on the western edge of the high with a greater chance of the system turning more to the northwest and north. Should the system do this, it will be in an environment more conducive for surviving as a tropical storm or hurricane.
"If Danny takes the westward track across the Leewards early next week, it would encounter progressively more resistance from the islands and greater wind shear, especially as it approaches Puerto Rico and Hispaniola," Kottlowski said.
While Danny will bring the potential for flash flooding, rough seas and surf as well as travel disruptions to the northeastern part of the Caribbean, it will also bring beneficial rain.

"A weakened Danny may be just what the doctor ordered for drought-stricken areas from the Leewards to Puerto Rico and Hispaniola with rounds of drenching rain with the more westward track," Kottlowski said.
There are other areas of concern in the Atlantic.
A significant area of disturbed weather has emerged from Africa.
This system will take a west-northwest path across the Atlantic, perhaps similar to Danny.
Additional disturbances will continue to move westward from Africa every several days through at least the end of the month. This pattern is very common for August into September.
Another system may develop near Bermuda over the next several days.
The feature near Bermuda may slowly form beneath a storm in the upper atmosphere. While a threat to the United States appears unlikely at this point, it could wander close to the Canada shoreline early next week and bring wet weather to New England.
During El Nino, the number of named tropical systems in the Atlantic basin tends to be lower than average.
AccuWeather is forecasting eight tropical storms, four hurricanes and one major hurricane for the 2015 season with two to three landfalls in the United States. Ana and Bill made landfall in the U.S. during May and June respectively.
Meanwhile, Kilo is expected to strengthen south of Hawaii. Should the system turn quickly to the north, there will be the potential for strong winds, pounding surf and heavy rain on part of the islands, by early next week.