Tropical Depression Four forms in Atlantic, could become a hurricane soon

MIAMI, Aug. 18 (UPI) -- A patch of well-organized thunderstorms west-southwest of of the Cape Verde Islands has strengthened into a tropical depression as it moves west toward the Caribbean.

Forecasters upgraded the system into Tropical Depression Four at 11 a.m. Eastern and expect it to become a named tropical depression later today. The next named storm will be Danny.

Also, a pair of twin cyclones in the Pacific -- Typhoons Goni and Atsani -- could pose a major threat to the Philippines and Taiwan in the coming days. Goni was at a category 3 (116 mph) and Atsani (139 mph) was at category 4 hurricane strength Tuesday morning.

The National Hurricane Center based in Miami gives the Atlantic storm a 90 percent chance of tropical storm formation in the next 48 hours and it could become a named storm as early as today.

Saharan dust and dry air from Africa to the north of the system could hinder its growth. As the storm becomes larger it is likely to ingest some of that air, weakening it.

At least one computer model (HWRF) was predicting the storm would become a category 1 hurricane by Thursday. It had sustained winds of more than 30 mph late Tuesday morning.

The NHC predicts the storm will be a category 1 by Friday and category 2 by Saturday, just east of the Caribbean.

The storm, moving west-northwest at 10 to 15 mph, poses no immediate threat to land but could create problems for the eastern Caribbean early next week.

Typhoon Goni could bring heavy rains and strong winds to the northern Philippines Wednesday and Thursday before turning northwest toward Taiwan.

Meanwhile, farther to the north an area of low pressure is expected to form within a couple of hundred miles of Bermuda over the western Atlantic Ocean by the weekend while it moves slowly northward. The chances of formation are slim and it poses no threat to land.

The peak of the Atlantic hurricane season happens in the coming weeks. It's been a quiet Atlantic season so far with the onset of El Niño conditions in the Pacific.