Greetings Science Folks! It is another interesting day here in Central Texas—hot yesterday and chilly today! Oklahoma had tornados yesterday, so for this, my last blog, I thought I would touch on what a tornado is. I will get back to that “my last blog” part, in a moment.
This is a picture of what people were looking at south of Oklahoma City--Thanks Weather Channel!
So, what is a tornado? According to Weatherwizkids.com, is “A tornado is a violent rotating column of air extending from a thunderstorm to the ground. “ Note, the words, “to the ground.” This is important because until a funnel cloud hits the ground, it is not considered a tornado!
Okay, I am going to back up just a little bit. Let’s cover some basic terminology.
A funnel cloud is “a rotating cone-shaped column of air extending downward from the base of a thunderstorm, but not touching the ground.”
A severe thunderstorm, according to NOAA (National Oceanic and Atmospheric Administration), is a storm that “has wind gusts in excess of 58 mph (50 knots) and/or hail with a diameter of ¾” or more.” (http://www.erh.noaa.gov/er/box/glossary.htm).
Hail!
Thunderstorm
Now that we have the terminology to understand the process, we can put all of our knowledge together! A cold front and a warm front come together.
The cold air pushes under the warm air which creates lift. If there is enough moisture in the atmosphere, and enough lift is created, a thunderstorm starts to form.
If the factors that created the thunderstorm are strong enough, you may have the makings for a severe thunderstorm.
Please note, the definition of a severe storm suggests that lightening has no part of whether a thunderstorm is severe or not. Lightening can occur with a storm or without a storm.
Lightening is “any form of visible electoral discharges produced by thunderstorms,” according to the NOAA Weather Terms Database.
Actually, lightening can occur at almost any time—in a snow storm, on a hot Michigan night…of course, it happens everywhere, not just Michigan, but that is what I grew up watching—heat lightening! Sorry, I digress!
Okay, back to tornadoes...so, the severe thunderstorm starts to build, and you start to see cumulonimbus clouds,
wall clouds, tail clouds,
and scud clouds.
(Scud clouds are “Small, ragged, low cloud fragments that are unattached to a larger cloud base and [are] often seen with and behind cold fronts and thunderstorm gust fronts. Such clouds are generally associated with cool, moist air, such as thunderstorm outflow.”)
Thank you NOAA, again, for your definition!
Anyway, you also might start to see a circular motion within the clouds. When the circulation starts to break out of the cloud, you are watching a funnel cloud form. When it connects to the ground, you have a tornado!
Now, there is a lot more to tornados and funnel clouds and severe thunderstorms and such. However, I know that you all love to research stuff, so I gave you the basics and you can use this wonderful tool called the Internet to find out more! I am including a few links that are really great resources for weather related information.
http://www.erh.noaa.gov/er/box/glossary.htm
http://www.weather.gov/education
http://www2.crivitz.k12.wi.us/Library/Kay/climate__weather_websites.htm
I can’t say I really endorse any of these, however, they are all good sites and there are so many more out there. If you are really interested, the National Weather Service has a citizen scientist program called “Skywarn Spotters” which you can read about at http://www.nws.noaa.gov/skywarn/. This is a great program that teaches you what to look for and how to help the weather folks make more accurate predictions. I mean, come on—meteorologists can’t be everywhere at once, and as citizen scientists, we can see things out our windows that they may not know is happening! It’s a great way to become involved in your own community and, in the event of an emergency, get help to where it is needed most! Okay, that is my plug for the NWS—I am a trained Skywarn Spotter and it is a lot of fun! Another great weather opportunity is CoCoRaHS, which can be found at the following website: http://www.cocorahs.org/Content.aspx?page=hail.
So, back to the beginning…this is my last post for the Mayborn Science Theater! I have been chosen for a great opportunity with the Hill Country Soil and Water Conservation District out of the Lampasas area! While I am very much looking forward to this opportunity, I leave with a heavy heart, as I have had such a great experience here! I hope that, as you read this, you will endeavor to continue on in your search for science and have a great time getting messy with it!
Weatherly yours,
Jacki
P.S. Incidently, the following sources are where I got most of the pictures at...and they are all pretty good themselves!
http://www.wunderground.com/resources/severe/tornadoFAQ.asp
http://www.wunderground.com/wximage/shauntanner/0?gallery=
http://www.srh.noaa.gov/bmx/?n=outreach_svr
http://www.floridalightning.com/Storm_Chasing_2007.html
http://valleywx.com/2012/07/27/scud-cloud-picture-from-woodville/
http://vermilionweather.com/wallshelf.php
http://www.erh.noaa.gov/iln/spotters/guide/
http://www.cocorahs.org/Content.aspx?page=hail