Tropical Storm Debby, the fourth storm of the 2012 Atlantic hurricane season, is spinning slowly through the Gulf of Mexico, producing heavy rains and thunderstorms along the U.S. coast.

The U.S. National Hurricane Center said Sunday that the storm has maximum sustained winds of 85 kilometers per hour and is expected to move north over the Gulf of Mexico during the next few days.

A coastal flood warning remains in effect until early Monday morning. The storm is expected to strengthen slightly as it churns across the Gulf at about six kilometers per hour.

Debby forced the suspension of eight percent of the region's oil and gas production.

Officials said nine production platforms and one drilling rig were evacuated. The reduced production is not expected to impact oil prices unless the storm strengthens and forces more production platforms to close.

This is the first time four tropical storms have formed before July 1 during the Atlantic hurricane season since record keeping began in 1851.