Based on reports from Hurricane Hunters , it is estimated the low redeveloped into Tropical Depression Ivan late on September 22 while located about 175 miles ( 280 km ) south-southeast of the mouth of the Mississippi River .
Based on reports from Hurricane Hunters , it is estimated the low redeveloped into Tropical Depression Ivan late on September 22 while about 175 miles ( 280 km ) south-southeast of the mouth of the Mississippi River .