Dear Tom, 
Do hurricanes and tornadoes always spin in the same direction?
Melissa Quane,
Collierville, Tenn.

Dear Melissa,
Hurricanes in the Northern Hemisphere always rotate in a counterclockwise direction. Tornadoes usually rotate in a counterclockwise sense – usually, but not always. Hurricanes are low pressure systems. When viewed from above, the wind circulation around such systems (in the Northern Hemisphere) is always in a counterclockwise sense. This is due to the deflection of the Coriolis effect, which acts to the right of the intended motion in inward moving air. In relatively small air circulations, such as in tornadoes, the Coriolis deflective force is much weaker. Consequently, the rightward deflection is weaker and in about five percent of tornadoes, the wind circulation is clockwise.