Damage and Impacts from High Winds
Damaging wind events can develop with little advanced warning. People outside may not have access to warning information, so boaters and campers are very susceptible.
In an extremely dry environment, little or no rain may reach the surface, but the winds may exceed hurricane force, and may approach the speeds of a weak to moderate tornado. In a wet environment, the microburst may be embedded in heavy rain, but its onset may be so sudden that it can catch pilots unaware. Damage attributed to tornadoes may in fact have been caused by downbursts.
The type of damaging winds most dangerous to aviation, especially during landing and take-off, is the type spawned by a microburst in an isolated rain shower or thunderstorm. Downbursts or microbursts are mainly known for their ability to produce wind shears which can slow airspeed and cause aircraft to lose altitude at a very critical time for flight near the ground. A plane will encounter strong headwinds followed by strong tailwinds as it enters and flies through a microburst. Only 27 people survived the Delta Flight 191 crash caused by a microburst that occurred in 1986 in Dallas-Fort Worth. However, great strides have been made in understanding and avoiding the risk from low altitude wind shear. Part of this success has been due to the progress made in detecting and distributing real-time information regarding these hazards.
HOW DOES NSSL CONTRIBUTE?
NSSL staff often assists the NWS in conducting damage surveys following a storm event to determine what kind of phenomena caused the destruction. Surveyors note damage patterns, what kind of damage occurred, which direction objects were blown, and the structural integrity of the objects damaged. The expertise of the NSSL scientists helps make conclusions about the event (damaging winds vs. tornado, etc.), and adds to their knowledge of storm dynamics near the ground.