Tropical Storm Erika Born in the Atlantic, to Threaten Leeward Islands at Midweek

By Brett Rathbun, AccuWeather.com Meteorologist

August 24,2015; 11:00PM,EDT

 

 

Tropical Storm Erika formed on Monday night and will track toward the Leeward Islands later this week.
As Danny tracks across the northern Caribbean islands, Erika will follow a similar track and bring another round of welcome rainfall.

Danny Impacts the Leewards

This system will be steered westward by a large dome of high pressure across the Atlantic during much of this week.
"Erika will closely follow the track of Danny and approach the Leeward Islands later this week," AccuWeather Senior Meteorologist Matt Rinde said.

Erika is currently located about 955 miles east of the Leeward Islands and is in an area of warm water and moist air.
Tropical systems are most likely to strengthen in areas of weak wind shear. If wind shear is too strong, the system becomes disorganized and weakens.
Satellite imagery of Erika (Image/NOAA) "Wind shear is when strong winds near the surface and aloft blow strongly from different directions," AccuWeather Senior Meteorologist Alex Sosnowski said.
Danny thrived late last week in a zone of low wind shear. Once it moved into an area of increasing wind shear near the Leeward Islands, the system weakened rapidly.
While Erika is forecast to strengthen over the next several days, wind shear may again cause the feature to weaken approaching the Leeward Islands. A track into the northern islands of the Caribbean would bring another dose of needed rainfall.
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Much of the eastern half of Puerto Rico is under at least a severe drought, according to the United States Drought Monitor. Because of this, water rationing programs are in effect on the eastern side of the island.
However, if this system slices north of the Leeward Islands, where wind shear is somewhat lower, then it could survive and perhaps strengthen again. In this scenario, steering winds north of the Caribbean Islands will likely allow the system to track northwestward and then northward over the western part of the Atlantic basin.
According to Kottlowski, the exact path this weekend into next week is uncertain at this time.
"All interests in the northeast Caribbean, Bahamas, Florida and the Southeast United States should closely monitor the progression of this system," Kottlowski said.
The AccuWeather Hurricane Center will continue provide information on this feature, as well as all other tropical features across all ocean basins.

Despite a quiet first half of the hurricane season across the Atlantic, late August and through September are typically the peak of tropical activity.
At this point in the hurricane season, water temperatures are at their warmest. This gives disturbances moving across the Atlantic from Africa the best chance for development.
In May, AccuWeather predicted eight tropical storms, four of those to become hurricanes across the Atlantic Basin during 2015.