Simplify the following text for a Grade 12 native English-speaking person.
Original: Late on August 14 , a Hurricane Hunters flight into the system reported a small circulation center , but at the time was not well-defined enough to result in the initiation of tropical cyclone advisories .
Simplified: Late on August 14 , a NOAA Hurricane Hunters plane that flew into the system reported a small circulation center , but at the time was not well-defined enough to begin tropical cyclone advisories .