A pair of tropical cyclones forecast to become hurricanes early next week are headed for the US Gulf Coast and will spin over the Gulf's warm waters simultaneously, a rare weather event that could cause massive disruption as they make landfall.There have never been two hurricanes in the US Gulf of Mexico at the same time, according to the National Hurricane Center. The closest event was in 1933, when a major hurricane made landfall in south Texas while a separate hurricane weakened to a tropical storm after crossing the Florida Peninsula, the NHC said. The last time two cyclones were in the S Gulf of Mexico was in 2002, when Tropical Storm Fay and Tropical Depression Edouard overlapped for about 18 hours, according to the NHC.Tropical Storm Laura and a separate tropical depression brewing near Honduras could approach the Gulf Coast as hurricanes next week in an area spanning Texas to the Florida Panhandle, according to the National Hurricane Center.Meteorologists say there is still a lot of uncertainty around the systems and how they develop and move in coming days, particularly as they cross land.Both storms currently look on track to remain separate, however, any interaction between the two could change their intensity or trajectory, said Dan Kottlowski of AccuWeather. It is unlikely they would combine, he added."More than likely one will become stronger, and inflict more vertical wind shear causing the other to weaken," Kottlowski. "But if they stay of equal strengthen, then they will probably prevent each other from getting really strong."In some cases when storms interact, they can orbit each other and the speed of one cyclone could accelerate the other, part of something known as the "Fujiwhara effect," said David Streit of Commodity Weather Group.Tropical Storm Laura, which is currently east of the Antilles, was upgraded from a depression on Friday and has sustained winds of 45 miles per hour (72 kph), according to the NHC. Laura is forecast to make landfall as a hurricane on Wednesday.Tropical Depression 14, which would be named Marco if it strengthens, is on track to make landfall on Tuesday near the Texas and Louisiana border. It would arrive around the three-year anniversary of Hurricane Harvey, which dumped a record 50 inches (127 cm) of rain on parts of Houston in August 2017 and caused billions of dollars in damage."My concern is that this doubles the number of people that have to deal with it and the potential damage it might cause," said AccuWeather's Kottlowski.He added that Tropical Depression 14 is likely to become the stronger storm as it is slated to pass over a relatively flat area of the Yucatan Peninsula before entering the warm waters of the Gulf of Mexico, where it can gain strength."Tropical Depression 14 doesn't look robust right now, but it looks to be in an environment conducive to strengthening," said Phil Klotzbach, a research scientist at Colorado State University.On Friday afternoon, the NHC said Tropical Depression 14 could be near hurricane strength as it approaches the Yucatan Peninsula on Saturday.Major oil producers BP and Shell on Friday said they were taking steps to prepare for the storm. BP said it was evacuating offshore personnel and shutting in production, while Shell said it had begun to evacuate non-essential personnel.