Friday, September 23, 2005

The Mathematics of Wind Speed

From the Audubon Society Field Guide to North American Weather:

"Damage from winds increases as the square of the speed; that is, the speed multiplied by itself. For example, the force of the wind in a weak hurricane (74 mph/119kph) is doubled when the wind increases to about 100 mph (an increase of the wind's speed by only one-third)...
In many locations in the United States, winds over 50 mph (80 kph) occur almost every year, and not too infrequently they reach 75 mph (121 kph) without causing much damage. However, since a 100-mile-per-hour wind doubles the damage, it is potentially much more significant."
As reports of Rita's wind strength change, we should bear this in mind. While the drop from 175 to 145 mph is significant, it does not mean she is not to be taken seriously. As of the writing of this post she is only 10 mph down from a Category 5, and is estimated to hit land tomorrow.

rita noaa 9.23

And watch out for those tornadoes in Texas.

(Note: All maps reproduced on this site courtesy NOAA are the most recent available at the time of posting.)

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