Oct 6 (Reuters) - Tropical Storm Nate is strengthening over the northwestern Caribbean sea and hurricane and storm surge warnings have been issued for the northern Gulf Coast, the U.S. National Hurricane Center (NHC) said on Friday.

The storm is located about 165 miles (260 km) north-northeast of Isla Guanaja, Honduras with maximum sustained winds of 50 miles per hour (85 km/h), the Miami-based NHC said.

Nate will move into the southern Gulf of Mexico Friday night and move near or over the northern Gulf coast Saturday night or Sunday, the NHC said adding Nate is expected to become hurricane by the time it reaches the northern Gulf of Mexico.

(Reporting by Karen Rodrigues and Vijaykumar Vedala in Bengaluru)