Tropical storm Cristobal was forecast to fasten towards the North Carolina coast on Sunday morning, although it is not expected to reach the land of the eastern U.S. shores.

In the meantime, Hurricane Bertha finally grew weaker over the Atlantic waters but a dangerous tropical wave south of Jamaica was predicted to take the form of a depression, as it headed towards Mexico's Yucatan Peninsula and the oil platforms of the Gulf of Mexico.

The U.S. National Hurricane Center announced that Cristobal intensified after it arose but afterwards its progress ceased and it held steady. Furthermore, the storm was not seen developing into a hurricane, a transformation which calls for at least 74 mph.

Cristobal was located approximately 45 miles southeast of Cape Fear, North Carolina by 11 p.m. EDT and was observed moving towards northeast, parallel to the coastline at 6 mph with 45 mph winds, the Miami-based hurricane center reported.

A tropical storm warning was in operation from north of Little River Inlet to the border between North Carolina and Virginia and up to 5 inches of rain are anticipated in coastal areas, according to the center.

Bertha, far to the east in the open Atlantic, had showed a worrying resistance as it passed over cool waters in the direction of remote Iceland. However, by late evening, the hurricane at last wore off and converted once again into a regular tropical storm.

Besides Bertha and Cristobal, the hurricane center was supervising an area of thunderstorms in the Caribbean that seemed very probable to become a tropical depression as it moved westward towards the Yucatan Peninsula and the Gulf of Mexico.

Oil markets pay great attention to Atlantic storms because of their ability to affect oil and gas production in the Gulf, where the United States fabricates a third of its petroleum.