Saturday, October 5, 2013

Joplin, MO EF-5 Tornado

This was an entry I wrote on May 21, 2012 as an intern for WTVO in Rockford, IL.  You can find this entry on the First Warn Weather Team website.
On May 22, 2011, no one knew what was going to happen with the weather.  Early in the morning, all the signs were pointing to a major severe weather outbreak somewhere in the Midwest.  More importantly, everything was primed for an extended tornado outbreak.  An early morning weather balloon launch from the Springfield, MO weather office indicated this as well.
First, let me explain the 4 things SEVERE storms need to develop/survive.  These kind of storms need instability, moisture, lift, and shear.  For instability, there was plenty of CAPE (Convective Available Potential Energy), which is a term for the amount of gasoline in the atmosphere to fuel storms.  Keep in mind that you don't need a whole lot of CAPE for severe storms (or any storms, for that matter) to develop.  Think about a car.  Even if there is just a little bit of gasoline in the tank, you will still be able to start the car and go somewhere.  In addition, the early morning sounding showed a very nice veering profile, which means the winds were turning clockwise with height.  Basically, winds that veer with height allow for storms that develop in that area to obtain rotating updrafts.  This, in turn, provides excellent support for tornado development, because a tornado is simply a violently rotating updraft.  Next, there was plenty of wind shear in this same profile, which would allow the storms that develop in this environment to become tilted.  In other words, this would allow these storms to last for hours, as the updrafts and downdrafts would not be interfering with each other.
On a side note, an updraft is air that is moving upward at a very fast speed.  This aids in storm development, and a downdraft comes from storms that are decaying.  If these two things are interacting with each other in the same place in the storm, the storm will not be able to sustain itself.

Anyway, I have already mentioned two of the four things required for the development of severe storms.  For the third item, we need some kind of lift to get the storms to fire off.  This can come in the form of a front, outflow boundary (from previous storms), dryline, etc.  In this case, there was a powerful cold front that plowed through on this day, and that acted as a lifting mechanism.

Moisture is the final ingredient needed to stroke a severe storm.  To give you an idea of what I am talking about, think of when you watch the weather on TV every night.  The meteorologist will often refer to the dew point and/or humidity.  Both of these are ways to measure moisture, and storms thrive in high moisture environments.
 Now that we have all these ingredients in one place, let's talk severe weather!!!  The big event on May 22, 2011, happened in Joplin, MO.  An EF-5 tornado rolled through and completely destroyed everything in its path.  On the side of this post, I have included some radar images from the event.  The images to the far left are the Radar Reflectivity, and the images to the right are Storm Relative Velocity, which is a measure of wind shear.  From top to bottom, the time stamps are 5:29 PM, 5:43 PM, 5:48 PM, 5:53 PM, and 5:58 PM.  Notice in the third image there is an area enclosed by a white circle labeled "debris."  Well, that is an example of what the radar is detecting, and it is known as a debris ball.  These occur with particularly destructive tornadoes.  Want to know more about this devastating event?  Please take a look at this link for a further synopsis of this event.

The Perils of Storm Chasing

I figure writing an entry about storm chasing and its associated risks/dangers would be appropriate, considering the activity that happened in NE/SD on Friday.  Many people feel they can simply jump into a car and go after storms.  Well, there is much more to that than they think.  Those people, often referred to as "yahoos", do not realize just how dangerous this hobby can be.  Not only do you have to deal with rapidly changing weather, you also have to deal with issues like other chasers, wildlife, terrain, fatigue, poor road networks, and potential vehicle break-downs.  Let me explain.

Obviously, getting up close and personal with nasty weather is the primary issue.  Even if you have high-end equipment to help you predict what will happen, you never know until it actually occurs.  There have been many instances when chasers were caught in the path of monstrous storms, and they were lucky to escape alive.  As an example, our group had the chance to see the El Reno, OK tornado this year.  Shortly after forming, it made a beeline in our direction, so we had to get out of there quickly.  If we would have waited any longer, I would not be here writing this entry.  It is a sobering reminder that we are puny human beings at the mercy of something much bigger than us.

Other storm chasers, and even non-chasers, tend to go bonkers when inclement weather threatens their area.  This means roads get plugged up with excessive traffic, because everyone wants to see what's going on.  The natives are often drawn to chaser traffic, and they become a part of the long lines of cars going down the highway.  Unfortunately, these natives usually do not have the expertise or know-how to be a successful chaser, so they do more harm than good.  The same can be said for some of the "chasers" out there.  There are some chasers who are out for one reason and one reason only: to get the "money shot."  This means they will do anything they can to obtain it, even if it means breaking traffic laws and putting their own lives at risk.  On the other hand, there are those who chase to simply view Mother Nature at her worst (or finest, depending on who you talk to).  This is the category I fall in, because it puts all my knowledge about weather to use.  Being able to see a gigantic supercell up close is an absolutely amazing experience, and just looking at pictures does not really do it any justice.

Wildlife and terrain/poor road networks are also issues storm chasers face.  There have been numerous times during my chasing experiences that we come across livestock that is not confined to a fenced off area.  Fortunately, cows tend to run away if humans take even one step toward them, but we still need to approach them with caution.  They can cause problems when they are in the middle of the road and will not move, so all you can do is sit back and hope they move.  Snakes, fire ants, and other creepy crawlies are also a part of the game.  You need to constantly be mindful of where you are stepping, especially when walking in tall grass.  Fire ant mounds are not always in the shape of a mound, as I have come across some that are completely flat.  Even though I have never been attacked by those things, I hear their bites are quite painful.  Snakes tend to congregate in tall, grassy areas, and rattlesnakes are very common in the Great Plains, which is where the prime chasing territory is.  In 2009, our group came across a rattler while photographing an abandoned house.  It was coiled up and ready to strike, so we made sure to keep our distance.

The terrain and poor road networks are also a couple more hazards chasers must deal with.  As an example, Cherry County in Nebraska has only 3 paved roads, with a few gravel/dirt roads sprinkled in the mix.  You need to be very precise in what roads you choose, because it could determine whether or not you get to see the storm from the angle you want.  On the other hand, Iowa has an excellent road network, so there is more room for error.  Regardless, you do not want to be caught in the path of a monster, even if you are in an area with plenty of roads to choose from.  The terrain can also be an issue, especially if you are chasing in a river valley or in the Sandhills of Nebraska.  River valleys tend to have a lot of trees, which means you will not be able to get a good visual of the storm.  This translates to you being unable to see if a tornado is being produced, so you will literally be chasing blindly.  Likewise, very hilly terrain can be a burden unless you are able to find a good vantage point.  Also, hills tend to cause issues with phone signals, which means you might be without internet for a bit.

Vehicle break-downs and fatigue are the other issues chasers have to endure.  Considering you could end up driving 600+ miles in any given day, your vehicle will need maintenance.  However, even routine maintenance may not be enough, especially if you get caught in storm throwing softballs at you.  If any of your windows break, it is best to call off the chase and get it fixed ASAP.  Likewise, gravel roads can cause flat tires, due to jagged rocks.  Stuff happens, so you need to be prepared for the worst.  However, fatigue is probably the next biggest hazard.  Being on the road for 12+ hours in a day is quite taxing, and you may not get to your hotel until 1 AM.  This is yet another reason why chasing is not for everyone, because your time chasing is usually more than your time sleeping.

Have I completely turned you away from storm chasing?  I hope not!!  When you have a healthy respect for the weather, your chances of surviving are much better.  Always make sure you have a back-up plan, because plan A or plan E might not work.  In a sense, chasing is a lot like playing chess.  One wrong move, and you end up in checkmate.  For those who are interested, there are a couple reputable groups out there, and I am a driver/guide for Tempest Tours.  I will post those links at the bottom of this entry.

Thanks for reading!!!

Tempest Tours (led by William T. Reid, Brian Morganti, and Dr. Bob Conzemius)
Silver Lining Tours (led by Roger Hill and Dr. David Gold)
College of DuPage (although I do not personally endorse them, they are led by Victor Gensini, Paul Sirvatka, and Dr. Walker Ashley, who are all very great at what they do)