The expected path of a disturbance in the Atlantic Ocean behind Hurricane Erin—with the potential to develop into a cyclone—has shifted since Tuesday, according to data from the National Hurricane Center (NHC).

Storms that ramp up so quickly complicate forecasting and make it harder for government agencies to plan for emergencies. Hurricane Erick, a Pacific storm that made landfall June 19 in Oaxaca, Mexico, also strengthened rapidly, doubling in intensity in less than a day.

Tracking Hurricane Erin, the first named storm of the Atlantic hurricane season, which weakened to a Category 3 storm early Sunday.