Thick oil from BP Plc’s Gulf of Mexico spill washed ashore in Mississippi for the first time as tropical storm Alex moved into the Gulf, posing a threat to the cleanup operation.

Alex, the first named storm of the 2010 Atlantic hurricane season, had sustained winds of 45 mph and was about 60 miles west-southwest of Campeche, Mexico. The system was moving west-northwest at 7 mph. Forecasters from the U.S. National Hurricane Center say Alex could become a hurricane in the next 48 hours.

They predict Alex will make landfall as a hurricane on Wednesday between Brownsville, Texas, and Tuxpan de Rodriguez Cano in Mexico, sparing BP’s oil collection efforts at its ruptured deep-sea well.