An active tropical wave moved offshore the African coast on the morning of September 14th. The system moved due west, losing
its thunderstorm activity, and moving innocuously through the tropical north Atlantic until it neared the Lesser Antilles, when
convection returned to the wave on the 19th. After scraping the coast of northeast South America, it turned west-northwest
and organized into Tropical Depression Nine on the 23rd as conditions aloft became more favorable for developement. That evening,
the cyclone strengthened into Tropical Storm Ian while moving through the central Caribbean. After tracking westward into the
western Caribbean, the system felt in the influence of an upper level trough to its northwest and turned sharply north-northwest,
becoming a hurricane due to a favorable interaction with the incoming upper level trough. After moving across western Cuba as a
major hurricane, Ian continued to strengthen upon approach to southwest Florida, making landfall at Cayo Costa and south of
Punta Gorda as a major hurricane. Increasing interaction with the nearby upper level trough led to extratropical transition
beginning in earnest as it crossed central Florida as a weakening tropical storm, and although it emerged from the east coast
of Florida as a tropical storm, it had hybrid characteristics it was never able to shed as it approached South Carolina. A
brief intensification back into a hurricane occurred offshore northeast Florida, but the system was tilted to the north
with height due to southerly vertical wind shear. This led to the premature appearance of landfall (based on radar reflectivity)
when compared to the surface observations. Extratropical transition was deemed to be complete soon after the cyclone moved
inland near Georgetown, South Carolina. Its surface circulation weakened out of existence across western Virginia as a
separate triple point low to the east took over and became a wet nor'easter for portions of the Mid-Atlantic Coast.
The graphics below show the storm total rainfall for Ian, which used rain gage information from National Weather Service River Forecast
Centers, South Florida Water Management District, National Weather Service Forecast Offices, and CoCoRAHS. Efforts were made to
subtract out the influence of the nor'easter that formed to Ian's east across the Mid-Atlantic States.
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