Simplify the following text for a Grade 13 native English-speaking person.
Original: The storm accelerated northeastward over an area of progressively colder water temperatures , and after a decrease in convection the National Hurricane Center ceased issuing advisories as Chantal began undergoing extratropical transition early on August 1 .
Simplified: When convection began to decrease , the National Hurricane Center stopped sending out advisories on August 1 when Chantal began to turn into an extratropical cyclone .