I was asked to write about what a microburst is. I thought I would take it one more step and talk about microburst, tornadoes and straight line winds.
A microburst is a small yet very intense downdraft that descends to the ground resulting in a strong wind divergence. The size of a microburst is typically less than 4 kilometers across. In miles that is between 2 to 3 miles. 2 miles is 3.218688 kilometers. Microbursts are capable of producing winds of more than 100 mph causing significant damage. EF 1 tornado speeds range between 86 and 109 MPH.
For more information on wind speeds or tornadoes go to http://www.spc.noaa.gov/faq/tornado/ef-scale.html .
Most microbursts don’t last longer than about 8 minutes.
Derechos are common in the Midwest and they are found a lot in fast-moving band of severe thunderstorms in the form of a squall line usually taking the form of a bow echo. Derechos blow in the direction of movement of their associated storms. Severe derecho wind is anything over 57 MPH, however winds can reach over 100 MPH at times.
I chased a severe wind event this year near Kirksville, MO that caused a lot of damage in its wake. I saw trees down signs blown off buildings windows broken and more in a few small towns northwest of Kirksville and in Kirksville itself. Damage was also reported form spotters in and around Hannibal MO.
A tornado is a powerful column of winds spiraling around a center of low atmospheric pressure. The winds inside a tornado spiral upward and inward with a lot of speed and power, winds inside a tornado can spin around at speeds up to 500 miles an hour, but usually travels at roughly 300 miles an hour. This makes the tornado one of the most dangerous storms.
Most tornadoes are small and have a short life span lasting only a few minutes if not a few seconds/ However some grow large enough to spawn smaller tornadoes known as satellite tornadoes.
Tornadoes are not only one of the most amazing storms in the US they are also one of the most dangerous.
Not only are tornadoes hard to predict, they can be hard to see. In high precipitation supercells, tornadoes can become “rain wrapped”, where the rain is so heavy it makes the tornado very hard to see and yet the tornado is still there.
One other thing people ask me is “how can you tell what caused the damage?”
Its hard to tell unless you have been to school and learned how to tell. I have not.
However, I asked my buddy, Danny Neal, to answer that question, and this is what he had to say:
“Straight line wind damage is usually, well, in a straight line. If the storm blows in from the west all the damage would be facing the east.
With a microburst the damage will be outwards from a spot. Imagine dropping a pebble into a pool. Watch the ripples and imagine where the microburst occurs are the “waves” the pebble creates. It is a diverging pattern.
A tornado, on the other hand, has a chaotic and convergent pattern. Take a look at this link: http://apollo.lsc.vsc.edu/classes/met130/notes/chapter14/tornado_mb_damage.html”.
Danny Neal is a really nice guy and a great storm chaser and forecaster. He has 14 years experience chasing, and two years of meteorology at College of DuPage under his belt. I recommend you check out his pages:
