Subtropical storm Olga hit Puerto Rico with heavy rains early Tuesday and the Dominican Republic was preparing to reopen hurricane shelters a week after the official season of hurricane ended.

Forecasters expressed their fears regarding the floods and mudslides that could be provoked by the heavy rains.

Olga hit northern coast of Puerto Rico overnight with winds up to 45 mph, causing blackouts leaving 76,000 people without power, CNN informs.

Around 7 a.m. its center was over the water, 45 miles east of Cabo Engano in the Dominican Republic.

According to the National Hurricane Center, Olga was moving westward at 15 mph.

Its force dropped from 45 to 40 mph, and forecasters said that it won’t pick up strength before reaching the coast of the Dominican Republic.

Hispaniola, shared by Haiti and the Dominican Republic, was expected to weaken the storm, the Guardian Unlimited reports.

Six inches of rain are expected to fall over Hispaniola, according to forecasters.

On Monday night a tropical warning was issued by the government of the Dominican Republican for the northern coast from Cabo Engano to Bahio de Manzanillo at the border of the Dominican Republic and Haiti.

Meteorologist Hugh Cobb said: "It is unusual since the season does end officially on November 30. However, in recent years we have seen quite a few December cyclones."

According to the National Hurricane Center, around 10 a.m. ET Tuesday, Olga was near the eastern tip of the Dominican Republic, and was moving west.

The Atlantic hurricane season began June 1 and it had 14 named storms, including six hurricanes.