Here We Go Again...

More severe weather is breaking out in the nation's midsection. 19 tornadoes were reported yesterday and already another one this morning. May is considered the peak of tornado season, so expect this pattern to continue. But in the wake of VA's tornado outbreak and all of the interest in tornadoes, I decided to dedicate a Weather Matters segment to tornadoes.


We've all seen the pictures. We all know just how powerful Mother Nature can be. Did you know that each year there are over 1,000 tornadoes that hit the U-S. Since we're entering the peak of the season, here are a few questions answered.

1. First, how does a tornado form?

Tornadoes form when warm moist air is trapped underneath a layer of cold, dry air. This is very unstable. Eventually the warm bottom layer gets pushed up. As it rises, it cools, forming clouds and thunderstorms. If the conditions are right, the rising air will spin around a central funnel - at speeds sometimes exceeding 250 mph. A tornado technically is born when this funnel cloud touches down on the ground.

2. Why are they so unpredictable?
Scientists do not fully understand tornadoes.


Scientists at the Storm Prediction Center, SPC, in Norman Oklahoma predict where tornado-generating storms are mostly likely to form each day. But it's extremely difficult to tell which thunderstorm will spawn a tornado.

3. How big are tornadoes and long can one last?
Damage paths can be larger than one mile wide and 50 miles long. Tornadoes can last from several seconds to more than an hour. Most tornadoes last less than 10 minutes. The Suffolk tornado lasted 15 minutes.

4. When / where was the largest/deadliest tornado on record?


The biggest recorded tornado was nearly two and a half miles wide.
It occurred near Hallam, Nebraska, on May 22, 2004.
But remember that size does not necessarily imply strength.

The most deadly single tornado in history was the Tri-state twister of March 18, 1925.



It moved across Missouri, Illinois and Indiana at speeds greater than 60 mph, this F5 tornado covered 219 miles and killed 695 people.

5. Where should you go if you hear there's a tornado warning for your area?
First, stay away from all windows! Your best choice is a basement or storm shelter. Get under something sturdy to shelter you from falling debris. If you don't have either, go to an interior room without windows, like a bathroom or closet. If you're on the road leave your car and seek shelter in a nearby building. If you're not near a building, get down in a sheltered low spot and cover your head with your arms.

Information and pictures courtesy of:
www.harkphoto.com
www.armageddononline.org
http://www.spc.noaa.gov/faq/tornado/
http://www.nssl.noaa.gov/faq/faq_safety.php
http://www.nssl.noaa.gov/edu/safety/tornadoguide.html