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| April 14, 2012 tornado in Kansas |
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 and be on the ground for over a hour!
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 if not impossible and yet the tornado is still there. That is why it is so important that you NOT go outside and wait until you see it to take cover.
Several conditions are required for the development of tornadoes. Abundant low level moisture is necessary to contribute to the development of a thunderstorm, and a "trigger" (perhaps a cold front or other low level zone of converging winds) is needed to lift the moist air aloft. Once the air begins to rise and becomes saturated, it will continue rising to great heights to produce a thunderstorm cloud, if the atmosphere is unstable. An unstable atmosphere is one where the temperature decreases rapidly with height. Atmospheric instability can also occur when dry air overlays moist air near the earth's surface. Finally, tornadoes usually form in areas where winds at all levels of the atmosphere are not only strong, but also turn with height in a clockwise or veering direction.
A tornado watch means conditions are favorable for the formation of a tornado in and around the watch area. During a tornado watch people should keep apprised of rapidly changing weather conditions.
A tornado warning means that a tornado is imminent or occurring within the specified area. A tornado warning can be issued either because of a Doppler radar indicated threat or because a tornado was reported by trained weather spotters or storm chasers, as well as emergency management personnel.
A tornado emergency is enhanced wording used by the National Weather Service (NWS) during significant tornado occurrences in highly populated areas. Although it is not a new warning type from the NWS. Tornado emergency generally means that significant, widespread damage is expected to continue and a high likelihood of numerous fatalities is expected with a large, strong to violent tornado.
~ Cody
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