Monday, October 28, 2013

More about Tornadoes by Lee Ann Grimm

As I plan to teach my students about tornadoes, some of the essential questions asked might be:

1. What particular areas and regions are tornadoes attracted to?
2. What controls the intensity of a tornado?
3.  Is their a particular balance of elements that are necessary for such a large tornado to form?

Areas of interest for students usually include size, frequency, locations and causes.  I found two articles that I thought may answer some of these inquiries for students.

 My first article reports that with tornadoes being the most lethal wind-related disasters in the world, on an average, about 800 tornadoes are reported in the United States yearly.  Although tornadoes are no more frequent in North America than any other industrialized region in the middle latitude, the intensity of these storms is more severe.  Tornadoes usually develop within intense thunderstorms classified as "Super cell Thunderstorms."
Although all 50 states in the U.S. can be hit by tornadoes, the main regions that are impacted most are Northern Texas, Oklahoma, Kansas, and Nebraska.  These regions are also known as "Tornado Alley."




 In North America, these atmospheric conditions develop in late winter in central gulf coast states, moving slowly northwest during the months of March and April.  May is the peak month for tornadoes in  the southern plains and the upper Midwest and Great Lakes region suffer mostly in the summer months.  In a 24 hour period, 60% of tornadoes hit between noon and sunset, 21% from sunset to midnight and 19% from midnight to noon.  Statistics show that tornadoes generally will only strike a North American city about every 250 years, with the exception of cities in Oklahoma. 

My second article talks more about the general patterns of tornadoes, some factors involved with tornadoes and why the United Stated is hardest hit by tornadoes. 

Tornadoes are defined as violent columns of rotating air that are usually visible, but not always.  Most tornadoes average 5-7 minutes long and are known to come in contact with the ground.  95% of tornadoes rotate counter clockwise because they move in the same general direction as the low pressure systems that spawn them.  As winds get pushed upwards in the "updraft", the prevailing direction rotation is counter clockwise.

Although hundreds of tornadoes affect the entire world, the largest number hit in the mid-west part of the United States, called "Tornado Alley."  Some factors in the United States  that make it a prime location are local geology, proximity to water and the movement of frontal systems. 


Five key reasons that the United States is hit hardest by tornadoes are:

1.  Central plains-perfect flat alleyway between the Rockies and the Appalachians creating a straight shot for cold polar air to clash with moist warm air.
2.  Other countries are shielded by mountains or geographic boundaries
3. The size of the United States if very large.
4.  Ocean front property
5.  Ocean currents are aimed at the East Coast.

I live in a town in Northwest Iowa and have fortunately never had to live through a tornado. Many towns that are within 30 miles of my hometown have been hit by tornadoes and extensive damage has impacted and destructed those communities.  I know most of these tornadoes hit between noon and sunset which statistics say that 60% of tornadoes do occur during this time.  All of these tornadoes included a thunderstorm before, during or after they occurred.  Now that I know more about location, frequency and causes of tornadoes, I really don't know as much about the sizes of tornadoes. My next inquiries include:
What is the average size of a tornado?
What does the climate and geographic location have to do with the size of tornadoes?
What regions have been impacted by the largest tornadoes?

Sources: 

 1. The Journal of Emergency Medicine. Volume 17. No. 1. p 67-73.1999.
      The Medical Impact of Tornadoes in North America 
      Jay J. Bohonos (M.D.) /David E. Hogan (D.O.)

2.  Weather About.com
      Tornadoes-How Tornadoes Form
      By Rachelle Oblack

3. Photos:
    en.wikipedia.org
    blog.al.com
     tornatrix.net
     johnenglander.net
     sodahead.com





 



Wednesday, October 16, 2013

Lee Ann Grimm and Oklahoma Tornado

Many tornadoes have swept through the United States in the last century, but one of the largest devastated El Reno, Oklahoma( located near Oklahoma City), on May 31, 2013.
The tornado was a top of the scale EF5 with winds reaching 295mph.  It measured 2.6 miles in width and 16.2 miles long which is recorded as the largest in history.  It took only a mere 40 minutes to kill at least 18 people.  The last record was 2.5 miles in width that hit Hal lam, Nebraska.

The tornado that hit El Reno was described as, "A huge funnel, made up of multiple smaller tornadoes rotating like horses around a merry-go- round."

Questions are being asked??????

What controls the intensity of a tornado?
Is there a particular balance of elements that are necessary for such a large tornado to form?
What particular areas and regions are tornadoes attracted to?  

Find out more in Lee Ann Grimm's next blog!!!!!!!

Sources: 

 1.  http://www.latimes.com
 2.  Photo-600x409-news.national geographic.com



Lee Ann Grimm and Tornadoes




El Reno tornado

Tuesday, October 1, 2013

Lee Ann Grimm and Extreme Weather

 Representation of a Tornado

I am wanting to teach a unit on extreme weather in my elementary classroom. At this point I do not know how many students are familiar with extreme weather and the effects that it has on them and the environment that they live in and so I thought that a great place to start would be with an "Extreme Weather 101."  I found a website by the Will Steger Foundation titled,"Extreme Weather 101."  The website included some great teaching and learning tools that I thought would be very helpful to my students and myself.

Many stories about tornadoes, flooding, snowstorms, and above and below normal temperatures have caught the nation's attention in the last decade.  The real questions are, "Is this climate change?", "Are specific weather events even linked to climate change?" and "How are instructors supposed to teach about this?"

Some of the questions that students are inquiring about include:
1. How does weather work?
2. What is the difference between weather and climate?
3. How do models work?
4.What does adaptation mean?

There are many supporting lessons for instructors to teach for various grade levels, for example, using graphs to chart climate data and also matching climate data to various locations. Another example is to have the students investigate the climate in El Nino and there are 5 activities for students using real data.

There are also various videos about extreme heat and how it is impacting urban communities and how we are adapting to temperature changes in the world. There are also pod casts that connect extreme weather to climate change and also the extreme weather in 2011.  There is a map of the United States that shows the different weather events from 1995-2011.  Supportive reading and websites are also listed for learning tools.

I thought that this website would give me and my students a great start on the extreme weather unit that I will be teaching

Source:  www.willsteger.foundation.org/climate-change-basics/extreme-weather-101