On September 21, an area of convection formed in the western Caribbean Sea associated with a trough of low pressure. Convection increased and a wide area of low pressure formed on September 22 as the convection moved northwestward towards the Yucatan Peninsula. On September 23 the area of low pressure moved over the Yucatan Peninsula and was creating thunderstorms from the southern Gulf of Mexico to the northwestern Caribbean Sea. Over the next few days the large area of low pressure was moving unevenly over the southwestern Gulf of Mexico, but convection was restricted from strong upper-level winds. By September 25 upper-level winds started decrease as conditions became more favorable for tropical cyclone formation and by that morning visible satellite imagery showed that a tropical depression could be forming about 180 mi (290 km) east of Tampico, Tamaulipas.