Complex sentence: Before making it final landfall, the hurricane rapidly weakened to Category 1 status before landfalling on August 19 south of Corpus Christi, Texas as a 75 mph (121 km/h) hurricane.
Split into simpler sentences: Before making it final landfall, the hurricane rapidly weaken to category 1 status. On August 19, the hurricane made landfall south of Corpus Christi, Texas as a 75 mph (121 km/h) hurricane.