MicroburstsBlue

Microbursts
Charlotte S. and Liza G. Blue Class

(Image 2)

Introduction: A microburst is a strong downburst of wind formed during thunderstorms, that reach speeds of 100 MPH and can last from 5 to 15 minutes(4). They have a width of 2.5(or less) miles(2). The cold heavy air given off plunges--at a horizontal angle-- towards the surface of earth then splashes against the ground(5). As the microburst hits the ground the edges swirl upward(3). Microbursts cause unpredictable and dangerous winds that can cause much damage. (Image 3)

Dangers:
 * High wind speeds of unpredictable and up to 100 mph winds can(4):
 * Hurt people and properties(1)
 * Damages trees(1+2)
 * As much damage as a small tornado(3)
 * Flatten trees and power lines(5)
 * Air planes during take off and landing because of the wind force(2)
 * Dangerous near airports because the strong winds above, below, and sideways, buffet the aircrafts causing crashes(5)

(Image 4)

Conditions of Formation:
 * Thunderstorms(all)
 * Rain(all)
 * Dry: The rain falls below the cloud base it then mixes with dry air. The rain begins to evaporate cooling the air, causing the density to lower and therefore the air drops faster and faster until it hits the ground.(3)
 * Wet: A wet microburst is the same as a dry microburst but it has rain since the surface of the earth is warmer.(3)
 * Click on link for images of microbursts forming: []
 * A small column of fast-sinking air, located below a thunderstorm, when hits ground it causes strong dangerous winds.(5)
 * Formed when rain falling from thunderstorm clouds evaporates under the cloud, cooling the air below it.(4)
 * Sudden changes in wind speed and direction called wind shear are common during microbursts.(4)
 * Occurs during low pressure, given off from thunderstorm clouds (commonly cumulonimbus clouds)(5)

(Image 1)

Historical Examples: A microburst hit Tulsa a little before 5 am on August 14, 2010. This microburst damaged mostly trees, fences, and buildings in the area. This microburst was sudden, and nobody had predicted it because they are very hard to predict. The winds reached 65- 70 mph. Fortunately, microbursts are common in this area and so people knew how to stay safe. Click on this link to find outmore about this event: http://www.tulsaworld.com/news/article.aspx?subjectid=11&articleid=20100814_298_0_Anearl188203

(Image 5)

Safety:
 * Microbursts have lead to many air disasters, the U.S government has spent millions on equipment at airports so fewer occur today.(5)
 * Microbursts are unpredictable and sudden, therefore making it hard to prepare for and to predict them.(2)
 * Something that you can do to protect against this is predict thunderstorms which will help. also one can get in the basement during what appears possible to turn into a microburst.(3)
 * One technology that can be used to predict microbursts is a Doppler Radar. This radar responds to precipitation particles which does have some drawbacks because not all microbursts have rain. (4)

Sources: 1. Hedding, Judy. "Microburst - What Is a Microburst." Phoenix - Phoenix AZ - City of Phoenix - Phoenix Arizona - Metro Phoenix. Web. 21 Nov. 2010. [].

2. Caracena, Fernando. "Microbursts." Forecasting Microbursts & Downbursts. Web. 23 Nov. 2010. .

3. "Microburst." TutorGig.com - The Tutorial Website. Web. 23 Nov. 2010. .

4. "microburst." Encyclopædia Britannica. 2010. Encyclopædia Britannica Online. 23 Nov. 2010 .

5. “Microbursts” What is a microburst? 2010. Whyfiles.org online. November 23rd 2010. http://whyfiles.org/2010/what-is-a-microburst/

Images: 1. http://addins.wrex.com/blogs/weather/?p=8014 2. http://addins.wrex.com/blogs/weather/?p=8014 3. http://www.fox44now.com/Global/story.asp?S=12795943 4. http://apollo.lsc.vsc.edu/classes/met130/notes/chapter14/tornado_mb_damage.html 5. http://whyfiles.org/2010/what-is-a-microburst/ 6. http://www.youtube.com/watch?v=NT3YbuGHfC4 (YouTube video)

media type="youtube" key="NT3YbuGHfC4" width="425" height="350" align="center"

This video shows a microburst coming down on earth. You can see the force of the wind and then the ends start curling up.