Microbursts, tornadoes and straight-line winds

I was asked to write about what a microburst is. I thought I would take it one more step and talk about microburst, tornadoes and straight line winds.

A microburst is a small yet very intense downdraft that descends to the ground resulting in a strong wind divergence. The size of a microburst is typically less than 4 kilometers across. In miles that is between 2 to 3 miles. 2 miles is 3.218688 kilometers.  Microbursts are capable of producing winds of more than 100 mph causing significant damage. EF 1 tornado speeds range between 86 and 109 MPH.

For more information on wind speeds or tornadoes go to http://www.spc.noaa.gov/faq/tornado/ef-scale.html .

Most microbursts don’t last longer than about 8 minutes.

Derechos are common in the Midwest and they are found a lot in fast-moving band of severe thunderstorms in the form of a squall line usually taking the form of a bow echo. Derechos blow in the direction of movement of their associated storms.  Severe derecho wind is anything over 57 MPH, however winds can reach over 100 MPH at times.

I chased a severe wind event this year near Kirksville, MO that caused a lot of damage in its wake. I saw trees down signs blown off buildings windows broken and more in a few small towns northwest of Kirksville and in Kirksville itself. Damage was also reported form spotters in and around Hannibal MO.

A tornado is a powerful column of winds spiraling around a center of low atmospheric pressure. The winds inside a tornado spiral upward and inward with a lot of speed and power, winds inside a tornado can spin around at speeds up to 500 miles an hour, but usually travels at roughly 300 miles an hour. This makes the tornado one of the most dangerous storms.

Most tornadoes are small and  have a short life span lasting only a few minutes if not a few seconds/  However some grow large enough to spawn smaller tornadoes known as satellite tornadoes.

Tornadoes are not only one of the most amazing storms in the US they are also one of the most dangerous.

Not only are tornadoes hard to predict, they can be hard to see. In high precipitation supercells, tornadoes can become “rain wrapped”, where the rain is so heavy it makes the tornado very hard to see and yet the tornado is still there.

One other thing people ask me is “how can you tell what caused the damage?”

Its hard to tell unless you have been to school and learned how to tell. I have not.

However, I asked my buddy, Danny Neal, to answer that question, and this is what he had to say:

“Straight line wind damage is usually, well, in a straight line. If the storm blows in from the west all the damage would be facing the east.

With a microburst the damage will be outwards from a spot. Imagine dropping a pebble into a pool. Watch the ripples and imagine where the microburst occurs are the “waves” the pebble creates. It is a diverging pattern.

A tornado, on the other hand, has a chaotic and convergent pattern. Take a look at this link: http://apollo.lsc.vsc.edu/classes/met130/notes/chapter14/tornado_mb_damage.html”.

Danny Neal is a really nice guy and a great storm chaser and forecaster. He has 14 years experience chasing, and two years of meteorology at College of DuPage under his belt.  I recommend you check out his pages:



Joplin Tornado, May 22, 2011

The day of the Joplin tornado started off like any other day of chasing. I spent about a hour looking at forecast models and talking to people about good target areas. We decided that due to time and money we were going to chase close to home instead of driving to southern Missouri.

So we started our chase going north toward Moberly, MO.  We chased a storm around in Randolph County for an hour or so and then jumped over to a warned cell in Howard County, where we saw a very nice rope tornado.

It very quickly moved behind the trees and we were unable to capture video. We tried every road we could find to get back to the tornado but were unable to get there in time.

We got on a couple more warned cells in the area but they were both HP cells and if there was a tornado it was much too rain wrapped to tell.

We decided to find a gas station and fuel up and regroup.  At this point we made a heart sinking discovery. We pulled up the radar image of the cell just west of Joplin and our hearts went into our guts we saw a very strong hook and reports from Twitter that debris ball was showing up on radar.

Seconds later we saw reports of a very strong and damaging tornado on the ground and moving toward a direct hit on Joplin, MO.

I can still remember the feeling. I lost all desire for chasing.  All I wanted to do was push the pedal to the floor and drive south and not stop until I got to Joplin.

We decided to make one more run at a warned cell east of Moberly, but just a few minutes into the chase we all realized that two things were true.

Number one, we had fallen too far behind and with darkness settling in the chase was over. 

Number two was that our want and drive was no longer on chasing; it was on helping the people of Joplin that needed the help more than ever.

As soon as I was in Columbia I started rounding up anyone who wanted to go to Joplin to help.  My friend Chris T. said to pick him up in Kansas City, MO, and he would go. I told him to pack a bag and I would be there in 2 hours.

I went home. and as soon as I walked in the door I threw my bag on the bed and packed a change of clothes, a few snacks, water and my vest.  I walked out the door and was on my way.

We stopped at a Walmart on our way to Joplin and bought cases and cases and cases of water, because the reports on the radio said they needed that the most.

When we got into Joplin, at first I saw normal damage such as power lines and down tree limbs broken.  But the further we got into Joplin, the worse it got.

We drove past Lowes to Home Depot, where we were told a command post was.  The Home Depot was 100% destroyed! They told us the command post was moved to Lowes, so we returned there, only to be told we were yet again sent to the wrong place.  This time they told us that we needed to go to the 911 Comand Post by the fire station.

On our way to the new location we passed gas stations that were gone, cars thrown into buildings, trees uprooted out of the ground.  I can not tell you in words how bad it was.

I have been a firefighter for five years and have seen a lot of things, things I would not wish my worst enemy to see.  But this was one of the worst if not the worst thing I had ever seen.

We arrived at the 911 command post and met some of the nicest people ever! One young lady walked us up to the fire station where we made contact with the guy in charge of search and rescue.

The fire chief told us that at dawn we would start search and rescue again and until then to nap and rest up.

We walked outside and saw easily 100-plus firefighters sleeping on the grass, using anything from arms to shirts to soda bottles as pillows.

By morning there were hundreds of firefighters standing in a two-bay garage waiting to find out the grid area they would be searching. Breakfast was made for everyone but almost nobody ate.  We were just ready to do what we came to do and try to find anyone alive.

We were teamed up with five more firefighters and started a house-to-house search for anyone alive that might be trapped. We spent all day looking at house after house, doing everything from cutting people out from where they were trapped to kicking in doors to check on elderly people who hadn’t been seen.

I personally worked two medical emergencies, on an older lady with back pain and a helping a lady who thought she saw a child having seizure.

After hours of searching, we saved people from being trapped and helped the hurt, but I am happy to say we found nobody dead in our grid. There were many who were not so lucky - many things I hope I never see again!

We worked for hours, only stopping briefly to drink water.

After working all of daylight and into evening they moved us off the search for food and rest and replaced us with fresh bodies. I would have loved to stay for days to continue helping, but I had a job to return to, and I wasn’t at all sure they would understand. So we had to call it a job well done and head home.

We stopped at Taco Bell for food half way home, and then I napped for the first time in over 24 hours, until we arrived at Kansas City.

From KC it was pedal to the metal to my own home where I took a nice warm shower and lay down. I should have fallen right to sleep but I was up for a couple hours thinking about how a person might have a warm bed now but in a matter of seconds, by a force of nature we can’t control, that can be taken from us, along with your family and friends who you love and care about.

So I want everyone to do two things:

One, tell your friends and family how much they matter to you and that you love them, because as much as we hate to admit it, in a matter of seconds you may not be able to tell them again. So tell them as much as you can, so that if the dreadful time comes you don’t have that regret.

The second thing is to ask you to please, every time you hear the tornado siren or you hear of a tornado warning close by, don’t blow it off.  Take cover!  I can tell you that while I was in Joplin, every time I found someone I asked where they were when it hit.  Everyone of them said they were taking cover. It might have been just in a hallway or in a basement, but my point is that the ones who took cover lived to rebuild the life that could have been taken from them in one second if they had not listened and taken cover. 

Joplin is still working to rebuild their city and recover from this disaster.  To find out how you can help, go to RebuildJoplin.org

How Midwest Storm Chasers was born

What is a storm chaser? There are many kinds of severe storm chasers:  scientists, thrill seekers, those who just want to see a tornado, and some who do it to capture video and or photos and sell them for a living.  I’m definitely a thrill seeker, and I’ve seen more than one tornado.  My goal, while it won’t happen overnight, is to do and be all the rest.

When I was about 14 years old a family friend who had a love for weather started to take me with him to chase the storms and watch the amazing lighting and other forces of nature. OK, well I think maybe “love” is an understatement.  Chasing was more of an obsession with him.  I was amazed at some of the things I saw and grew to love storms more than most. I saw hail as big as ping pong balls, lighting that split trees in half and flash flooding strong enough to not only wash out roads but wash out anything that got in its path (trees, cars, houses, etc.).  We would stay out much past my bedtime and watch lighting and hail come down stronger than I had ever seen before.

When I was in school I spent a lot of time reading books on weather - everything from tornados to rain to snow.

At the age of 20 I joined Cooper County Fire Protection District and spent four years running emergency calls for service at all hours of day or night, rain or shine.

Every year I would attend a storm spotter class in hopes to learn something or meet someone new.

Every time there was even a small chance of storms I would be at the fire station looking at multiple radars watching the storms roll in.

At the age of 22 I started to chase storms all over Missouri with my friend Ian Young, who is now a part of the Midwest Storm Chasers team. We saw many storms and came very close to seeing a tornado more than once but never could to seem to be there in time.

At the age of 24 I decided to take chasing to a new level and began to chase in states beyond Missouri.

First stop was Illinois, on a chase with my two buddies Ian and Chris, where we met one of the best chasers and one of the nicest guys I know, Greg Johnson. He was chasing alone because it was a good day to chase, and he us to chase with him.

Greg is a storm chaser and photographer from Canada. He drives down into the states a few times a year to chase and to take pictures of some of the most amazing and dangerous storms of the year.  He has some very amazing pictures and stories to share on his website at http://www.tornadohunter.ca/. 

We chased with him all day and into the night in Illinois, where I got to see and capture video and pictures of my first tornado!  

After a short break from chasing, Ian and I went with Greg Johnson to chase for “a day” in the Springfield, Missouri area. One day turned into a 3-day chasing adventure in Oklahoma and Texas and Arkansas.

While we were down there we didn’t see a tornado.  However, we did get to meet Reed Timmer and Tim Samaras, stars of the hit TV show Storm Chasers. We got the pleasure of chasing with them for two full days and got to stand outside the hotel and talk to Mr. Timmer for almost an hour.

We did get to see one of the most amazing super cells I have ever seen – or driven through.  It was the most exciting and heart pounding things I have ever done. That is one weekend I will never forget.

While driving back to Missouri from Arkansas, I decided I wanted to chase storms more often and not alone. So some of my best friends and I created a chase team:  Midwest Storm Chasers. Ian has been a firefighter for eight years and has had a love for weather for a long time. He has been an active chaser for one year going on two. Ronny has been a firefighter for seven years and an active chaser for four years. Chris M. has been a firefighter five years going on six and has been active chaser for one going on two years, has had a strong love for weather for longer than that but is an active lieutenant with the fire department and that has taken away from his free time to chase. Emily (our only female chaser) is our newest member and is just now starting to chase but loves every minute of it.   And don’t let me forget Greg Johnson, who we only get the pleasure of chasing with a couple times a year.  To learn more about Greg, go to http://tornadohunter.ca/tornado-hunter-greg-johnson/.

I made a Facebook page that I post on while chasing so everyone can follow us as we chase all over the Midwest and down tornado alley.  Feel free to “LIKE” the page at http://www.facebook.com/#!/pages/Midwest-Storm-Chasers/188106217909052.  Next year we plan to not only chase storms but stream video live from our dash camera. We also hope to take pictures and video and give people the chance to buy them.

This year our team has chased in many states, including AR, TX, OK, MO, IA, KS, NE and IL and we’ve seen two confirmed tornados. There are a couple times we have been very close to “rain wrapped” tornados but if I can’t see it I don’t count it.

(Rain-Wrapped Tornado:  “HP (high precipitation) supercells commonly have rain-wrapped tornadoes. Often an observer can not tell the difference between a rain-wrapped tornado and a heavy rain curtain until the tornado or rain curtain is right on top of them. Many motorists have been killed by rain-wrapped tornadoes.” http://www.theweatherprediction.com/habyhints/51/ )


There are many more chases to come and I am always looking for ways to improve both the chase team and my Facebook page, so if you would like to be a storm chaser or have ideas on ways to improve, contact me by commenting on a status on the page or e-mail me at crofmo@hotmail.com


Cody Robertson

Firefighter/ Severe storms chaser