Tornado Facts and Safety

I thought I'd continue on the topic of tornadoes for today and provide you with some commonly asked questions about them, follow by safety tips for when one is headed your way.  If you have any questions, please ask in the comment section and I'll get back to you as soon as I can.

How do tornadoes form?

A classical answer of "Tornadoes form when warm moist air from the Gulf meets cold Canadian air and dry air from the Rocky Mountains" is an extreme oversimplification!  Many thunderstorms that form under these conditions never even come close to producing tornadoes.  The truth is, we don't fully understand and know why tornadoes form.  We do know that the most destructive and deadly tornadoes occur under supercell thunderstorms (massive rotating thunderstorms with a well defined circulation also known as a mesocyclone).  The VORTEX program performed over the summers of 2009 and 2010 set out to gather data to better learn how tornadoes actually form.  Recent theories and results from the program suggest that once a supercell thunderstorm/mesocyclone is underway, the development of the tornado is related to the temperature differences across the edge of downdraft air wrapping around the mesocyclone.  However, tornadoes have been know to form without this temperature difference, such was the case with the destructive May 3rd, 1999 tornado that struck Moore and Oklahoma City, Oklahoma.    Thus, we're are basically back to square one - we truly do not know.  But if you would like more indepth information on theories, just ask me and I can show you some papers from my college years.

Does hail always come before the tornado?  How about rain, lightning, or pure silence?

In truth, hail, rain, lightning or that erie silence do not alway come before a tornado.  The hail, rain, and lightning characteristics will vary from storm to storm and moment to moment in time.  While large hail is a characteristic of a severe thunderstorm and can happen before a tornado, don't always use it as an indicator.  All four of these are not reliable predictors of a tornado threat.

Do tornadoes really skip?

I asked this question once myself!  I had envisioned a tornado bouncing from hilltop to hilltop in a very cartoon-like fashion.  But in reality, they really don't "skip".  By classical definition, a tornado must be in contact with the ground.  There is currenly a big disagreement among meteorologists over whether or not multiple touchdoens of the same funnel mean different tornadoes.

What happens when two or more tornadoes come together?

This is a very rare occurance, but it has actually been caught on tape.  Basically what happens is that the larger and stronger tornado will simply pull in and absorb the smaller, weaker tornado and continue on its course with little change.

What is the Enhanced F-scale?

Most people are somewhat familiar with the classic F-scale (or Fujita scale - named after Dr. Fujita who developed it) but are not familiar with the new Enhanced F-scale (or EF-scale).  The EF-scale is a much more precise and robust way to assess tornado damage than the original F-scale.  It classifies damage on a scale of EF0 to EF5 by using 28 different types of damage indicators and takes into account the type of buildings/structures, how well they are constructed, and what structures are made of.

Can't we weaken or destroy tornadoes somehow?  Like by bombing them or sucking out their heat with a bunch of dry ice?

Wow.... I found this one and I just had to include it!  Basically, the main problem is that anything that could possibly stand a chance at affecting a tornado (i.e. a hydrogen bomb!) would be more deadly and destructive than the tornado itself!  And the idea of using huge piles of dry ice to destroy temperature differences is very hard to actually deploy in the right place quickly.  Basically, the legal ramification of doing either of these things and then inadvertently hurting someone or destroying property dramatically outways the benefits.... so very very bad idea!

Tornado Safety Tips

• In a house with a basement, avoid all windows and get in the basement and under some kind of sturdy protection.  Know where very heavy objects are on the floor(s) above and do not go under them - if the floor weakends, they could fall through and crush you.
• In a house without a basement. again, avoid all windows.  Go to the lowest floor of the home and in a small interior room, under a stairwell, or in an interior hallway with NO windows.  Crouch as low as possible to the floor, facing down and cover your head with your hands (like you practiced in school!).  Even in an interior room, try to cover yourself with some sort of thick padding (i.e. a mattress, blankets, etc.) to protect yourself from debris.
• In an office building or hospital:  Go directly to an enclosed, windowless area in the center of the building and stay away from glass.  If you can, get on the lowest floor possible.  Then crouch down and cover your head.  Interior stairwells are usually good places to take shelter, and if they are not crowded, get to the lowest level possible as quickly as possible.  And avoid elevators!
• In a mobile home:  Get out!  Even if your home is tied down, you are more likely to be safer outside!  If your community has a tornado shelter, get there fast.  If there is a sturdy permanent building within easy running distances, seek shelter there.  Otherwise, lie flat on low ground away from your home and protect your head.  If possible, use open ground away from trees and cars which can be blown onto you.
• At school:  Follow the drill!  Go to the interior hall or room in an orderly way and do as you are told.  Crouch down, head down, and protect the back of your neck with your arms.  Stay away from windows and large open rooms like gyms and auditoriums.
• In a car or truck:  If the tornado is visible, far away, and the traffic is light, you may be able to drive out of its path by moving at right angles to the tornado.  Otherwise, park your vehicle as quickly and as safely as possible and out of traffic lanes.  Get out and seek shelter in a sturdy building.  If in the open country, run to low ground away from any cars.  Lie flat and face-down, protecting the back of your head with your arms.  AVOID SEEKING SHELTER UNDER BRIDGES & OVERPASSES!
• If outdoors:  If possible, seek shelter in a sturdy building.  If one is not available, lie flat and face-down on low ground, protecting the back of your head with your arms.  Get as far away from trees and cars as you can!

Well... I hope you enjoyed these facts about tornadoes and know the safety tips.  They could save your life!  Tomorrow, I'll be talking about a different subject about severe weather, so check back sometime tomorrow!