A satellite image taken Wednesday shows tropical storm Danny visible to the east of Nassau and on a northwestward track. (Weather Underground/Associated Press)

Meteorologists say tropical storm Danny, which is expected to bring high winds and heavy rains to Atlantic Canada by the weekend, may not make hurricane strength.

Danny was 650 kilometres east-northeast of Miami at 8 p.m. ET Thursday, according to the Canadian Hurricane Centre. The storm has sustained winds of about 83 km/h and is expected to gradually gain strength over the next 48 hours, the hurricane centre said. Danny is plodding to the north-northwest at nine km/h.

"Eventually Danny will produce rain on Saturday night or Sunday but it is too early to determine amounts," the hurricane centre said.

Canadian forecasters said Danny will eventually weaken as it moves through Canadian waters, but they added that marine warnings for storm force winds will likely be posted overnight for southwestern parts of the Maritimes.

A tropical storm watch is currently posted for portions of the North Carolina coast.

Danny is the fourth named Atlantic storm of the 2009 hurricane season.

Thursday's forecast from the Canadian Hurricane Centre indicated Danny will likely take a similar path to Hurricane Bill, which reached Atlantic Canada last weekend.

Hurricane Bill hit Nova Scotia on Sunday with high winds, heavy rain and dangerous surf. The storm knocked out power to thousands of Nova Scotia homes and businesses. Bill reached Newfoundland late that day, blasting the province's south coast with winds of 70 km/h and gusts to 100 km/h.