MORE TOOLS TO MEASURE HURRICANE WINDS

This year all the hurricane hunters will use an instrument to measure winds at the surface of the ocean which is more accurate than dropping a measuring device from the plane to the water. A Stepped Frequency Microwave Radiometer, SFMR, measures the ocean roughness caused by wind stress and can compute the magnitude of wind velocity. This will supplement a dropsonde which is ejected form the bottom of the plane and takes measurements of wind speed, direction, humidity, and pressure. Last year only 1 C-130 airplane had the SFMR onboard. In 2008, all eight C-130s will have the instrument in addition to two NOAA P-3's which fly out of MacDill Air force Base.

When we report the wind speed of a hurricane the elevation of the wind is taken at 33 ft. Wind speed is determined by factoring out gusts by averaging all the gusts over one minute to arrive at a sustained wind speed. A tropical storm becomes a hurricane if the wind is 74 mph or higher. Once the winds blow over 110 mph a hurricane becomes dangerous enough to be classified a major hurricane able to cause extensive damage. Hurricane Katrina was a cat 3.