Published Saturday, August 24, 2002
MERCER COUNTY
By Joe Pinchot
Herald Staff Writer
The storm that ripped through Mercer County Thursday created a wind event called a microburst, not a tornado.
But meteorologist Russell DeMaris said microbursts can be just as damaging as tornadoes, and added that 20 years ago scientists probably would have labeled Thursday's roof-ripping, tree-uprooting wind storm a tornado.
The microburst created wind gusts of 65 to 70 mph, and left a one-mile-long, one-half-mile-wide path of destruction, mainly in South Pymatuning Township, said DeMaris, of the National Weather Service in Pittsburgh.
There was no evidence from radar or damage patterns that winds had swirled, which would be the tell-tale sign of a tornado.
A microburst is the sudden downward rush of air caused when rain or hail falls from a storm cloud. The speed of the wind often is accelerated by gravity, DeMaris said.
The wind hits the ground and bounces outward, he said.
Tornadoes are spinning columns of air.
Microbursts -- and their higher-velocity siblings called macrobursts -- and tornadoes have different signatures of destruction, although the kind and severity of damage can be the same.
In tornadoes, trees often are twisted, while microbursts tend to blow the tops down, DeMaris said.
Microbursts, also called gust fronts, are from the front of a storm, while tornadoes emerge from the back of the storm.
The scientific difference between microbursts and tornadoes matters little when it comes to hitting the ground.
"Anything that packs 65-70 mph winds is going to be damaging and, if the proper protection is not taken, can be deadly," DeMaris said.
When the National Weather Service issues severe thunderstorms warnings, people should take the same precautions as they would for tornado warnings, he said.
"The most important thing the public needs to realize is both microbursts and tornadoes are serious things and should not be taken lightly."
You can e-mail Herald Staff Writer Joe Pinchot at jpinchot@sharonherald.com™