A mid- to upper-level low cut off from the main belt of the Westerlies and dropped over the Bahamas on May 25th. This caused
the formation of an inverted surface trough to the north of the southeastern Bahamas on the 25th which drifted west to west-
northwest. Despite southwesterly vertical wind shear, thunderstorms developed to the northeast side of the trough leading to
the development of a well-defined surface circulation early on the morning of the 27th. By afternoon, a tropical depression
was deemed to have formed 180 miles northeast of Great Abaco Island. The system picked up its pace to the west-northwest
as vertical wind shear became more south to southeasterly. The depression strengthened into a tropical storm on the morning
of the 28th about 195 miles south-southeast of Charleston. During the night of the 28th, vertical wind shear increased leading
to Bonnie's weakening. It regained tropical depression status on the morning of the 29th while just offshore South Carolina,
making landfall soon afterward. After looping west of Charleston, Bonnie headed northeast while the system lost organized
central thunderstorm activity. The remnant low turned east and re-entered the Atlantic on the evening of the 30th. On the
31st and June 1st, Bonnie turned eastward and produced intermittent convection near its center. By the evening of the 1st,
thunderstorm activity became more organized and persistent near its center and it became a tropical depression once more
just to the southeast of Cape Lookout. Bonnie accelerated northeast, moving just east of Cape Hatteras on the morning
of the 2nd. The cyclone turned east, becoming a tropical storm again during the morning of the 3rd. While moving over
cooler waters on the 4th, Bonnie again became a remnant low during that evening. By late on the 7th, Bonnie became a frontal
wave and dissipated west of the Azores during the afternoon of the 9th.
The graphics below show the storm total rainfall for Bonnie, which used rain guage information from the National Weather
Service River Forecast Centers, Forecast Offices, and CoCoRAHS.
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