May 30, 2002

Yes, there are several parts in the world where tornadoes simple can't form. Namely those areas where no thunderstorms form. These are the dry dessert areas and both polar regions.

May 29, 2002

The sound of a tornado depends merely at what distance you listen. Also the strength of the tornado has some influence on the tone of the sound. A strong tornado sounds like a freight train while a thin rope tornado sometimes produce a high whistling sound. From nearby the sound of a large tornado is terrifying, because of all kinds of debris that is picked up and is swirling around.

May 28, 2002

A dust devil forms over a strongly heated surface. We can see them quite often on sunny days with not to much wind. You don't need any clouds to let a dust devil form. For a tornado you really need a big thunderstorm overhead. Furthermore a tornado is much bigger and powerful than a dust devil.

May 27, 2002

Most tornadoes occur between 5 and 9 PM, though some of them indeed occur during night. Those are very dangerous because of the simple fact that they are not visible from the ground.

May 26, 2002

In theory, tornadoes should be grey because of the water droplets that they contain. Like a cloud, it's colour varies, depending on how big the water droplets in it are. As a tornado usually contains a lot of droplets as well as a lot of debris, it shows dark most of the times. Add the thick surrounding clouds to the picture and it surely looks grim.

May 25, 2002

No, not all tornadoes look like a funnel. The stronger tornadoes (like the one we saw on May 11th 2000) look like an overhanging dark cloud on the ground. Sometimes it looks like a fire is going on because the debris and dust that the tornado spins up, looks like the smoke plume of a fire.

May 24, 2002

May 11th 2000 we captured a tornado at a distance of 1 mile! This beast was rated an F3. We were able to film it for 6 minutes which is quite a long time. It was a really an unforgettable experience, though really frightening for a few minutes. Rule number one is that you must be 100 % sure that the tornado track is not towards your position.

May 23, 2002

Basically, we chase to study thunderstorms, mostly by filming and photographing, and combining weather maps, radar images, and things we observe on the ground. As a meteorologist, you mostly look at weather maps but with a little chasing experience you can actually tell what will happen on the ground and what type of severe weather will occur (wind gusts, size of hailstones, andspout or tornado). - Answered by Jules.

May 22, 2002

The Midwest is a region where large temperature differences occur. Along an almost permanent boundary between the cold and warm air, severe thunder storms can develop because of warm and humid air from the south is more or less colliding with this boundary and colder air masses. When winds on the ground and aloft are in a favourable direction, tornadoes can form. - Answered by Rob.

May 21, 2002

What equipment do you use in tracking these big storms? We mainly use our laptop to go on the internet. This way you can take a look at the forecast maps and observations. We do this when we start the day in the early morning with a weather briefing.
During the day we use the laptop and our mobile phone to go on the internet again and pick up the latest SPC- forecasts, radar- and satellite images and observations. In the afternoon your own knowledge becomes more important. We measure temperature and dew point ourselves. We have a small television which is useful when storms have formed. The local weather stations do give useful information. Finally we have NOAA weather radio and we listen to storm spotter frequencies.

May 20, 2002

Always try to move perpendicular on the tornado-track and you will be SAFE. If this is not possible, take shelter in an interior room (like the bathroom far away from windows) or preferably a cyclone-shelter. Highway overpasses are not safe to hide under!

May 17, 2002

Tornadoes can stay almost stationary at times but can reach more than 50 miles an hour as well. They often move fast in the winter months. In the tornado wind speeds can reach more than 275 miles an hour!

May 16, 2002

Very small chance; less than 1 %.

Storm Chaser Facts

Rob, Coen and Eric are meteorologist at Meteo Consult and we all work and live in Wageningen. Jules is a freelancer in meteorology and is living, nowadays, in the extreme north-eastern sections of the Netherlands.

What is your background?

Verrijn Stuart has always been interested in weather. He began his full-time career as an economist at KNMI, the Netherlands weather service. While there, he decided to become a meteorologist.. Four years ago, Verrijn Stuart joined Meteo Consult, which put him through a rigorous training program and made him a forecaster.

Stuart's scariest chase moment occurred April 30, 2000: "We were finishing a day of chasing and a squall line was approaching. It was getting dark so it was hard to see anything. We knew the storm was approaching, but we didn't know what was coming. A tornado could easily have been there and we wouldn't have seen it." Fortunately for the team, the squall line passed without producing a tornado.

Groenland first became interested in weather when he was young. "At eight or nine years of age, I started reading children's books about the weather." Although he was interested in tornado chasing for over a decade, "I didn't decide to go chasing until I met several meteorologists [at Meteo Consult] who shared the same interest."

Terpstra's interest in meteorology started when he was young. When he was 12 years old, the Netherlands suffered through a harsh winter. After that, Terpstra began keeping a diary of daily weather readings using an outdoor thermometer he purchased with his allowance. Eventually he bought other equipment and became an amateur weather observer. In 1994 Terpstra earned a masters degree in oceanography with a focus on meteorology at a Dutch university. He has been weather forecasting with Meteo Consult since then.

Terpstra says he likes to chase tornadoes because "you see the meteorology developing in front of your eyes. Knowledge of meteorology [from a textbook] will only get you halfway. You have to see it to truly understand it."

Geirneardt
Jules studied Geophysics and worked 9 years for Meteo Consult. He is now a freelance radio-forecaster. Geirneardts scariest chase moment occurred in 1996, his first-ever chase. "We got our van stuck in the mud just as a supercell storm was approaching. We had to abandon the vehicle and find shelter in a ditch. The storm passed right over us with fierce winds and lots of lightning. Luckily for us, a tornado didn't form. We were really vulnerable if one did form."