Wind speeds produced by downbursts can reach over 100 mph and produce damage similar to a tornado. However, downbursts damage paths are usually broader than tornado paths. The wind is moving in a straight-line as opposed to rotating like a tornado. Therefore, straight-line damaging winds from a thunderstorm is generally caused by a downburst. In aviation, the term wind shear is used.
Wind shear is the change of wind speed and direction.
A downburst is extremely dangerous to aircraft on takeoff and landings because of the strong wind shear. Wind speed and direction is in constant flux and the pilot can not compensate fast enough. A downburst larger than that would be called a macroburst. It is provided free of charge with the request that when you do encounter severe weather, you report it to the National Weather Service. The spotter training class includes 100 slides that help you learn how to pick out visual clues from clouds to help determine the severity of a storm.