Over the second week of September, Ophelia meandered off of the southeast coast of the United States due to weak steering currents. The system, which began as a depression over the Bahamas on September 6, 2005, twice stalled out and made loops: once just east of Cape Canveral, Florida, and the other farther out to sea east of Georgia. Ophelia also flip-flopped several times between a strong tropical storm and a weak Category 1 hurricane. Despite its very slow movement, which usually leads to weakening due to upwelling of cooler water, Ophelia has maintained itself as a result of warm waters and its proximity to the Gulf Stream.
The Tropical Rainfall Measuring Mission (or TRMM) satellite has been following Ophelia’s progress along the East Coast. This image shows the height of the precipitation columns within Ophelia with a cutaway view through the southern part of the eye. The large eye is easily visible in the center along with the area of intense rain in the southwest corner of the eye (dark red area). However, there are no tall towers surrounding the eye that might indicate imminent strengthening.
Launched in 1997 to measure rainfall over the tropics, TRMM has proven to be a valuable tool for monitoring and studying tropical cyclones. TRMM’s compliment of instruments includes the TRMM Precipitation Radar (PR), the only radar capable of measuring precipitation from space, and the TRMM Microwave Imager (TMI), a passive intrument that can also measure rainfall. TRMM is a joint mission between NASA and the Japanese space agency JAXA.
Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).