Original sentence: It continued to strengthen, becoming the first major hurricane of the season on the morning of August 5.It rapidly strengthened that morning as an eyewall quickly developed
Edited sentence: It continued to rapidly strengthen, becoming the first major hurricane of the season on the morning of August 5, when the NHC upgraded it to a Category 3 hurricane.It rapidly strengthened that morning as an eyewall quickly developed, the rapid intensification being attributed to warm water along the forecast track, which allowed for more rapid intensification