Simplify the following text for a Grade 13 native English-speaking person.
Original: Despite an overall disorganized structure , with a poorly defined circulation and an upper-level low aloft , the National Hurricane Center initiated advisories on Subtropical Depression Ten at 1500 UTC on September 21 while it was located about 40 miles ( 60 km ) south of St. Vincent Island , Florida , citing `` the potential for additional development right along the coastline . ''
Simplified: In spite of its bad organization , with a disorganized circulation and an upper-level low aloft , the National Hurricane Center started advisories on Subtropical Depression Ten at 1500 UTC on September 21 while it was located about 40 miles ( 60 km ) south of St. Vincent Island , Florida , stating `` the potential for additional development right along the coastline . ''