NSSL | Education | Ideas

Ideas for Teaching

• Stereo photography
• Why radar can't (usually) see tornadoes
• Graphing information
• Vectors for wind speed
• Calculating %
• Simple math
• Not so simple math
• Wildflowers & rainfall

Vectors Help You Calculate Wind Speed

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In 1994, scientists at the NOAA National Severe Storms Lab and OU Cooperative Institute for Mesoscale Meteorological Studies wanted to test their hypotheses about how tornadoes formed but there was no way to do it with routine weather observations.

Since many of these tornadogenesis hypotheses involve properties such as temperature, dewpoint, pressure, wind speed and wind direction of air surrounding where a tornado forms, they got the bright idea to essentially mount a surface weather station on a car. By mounting the weather station on a car, scientists can attempt to position their instruments around a tornado - or any other weather feature - and follow it along. We call these vehicles mobile mesonets, since they comprise a mobile, meso- (middle-scale) network of weather stations.

The data from the roof is processed and ingested into a laptop computer in the vehicle. Calculations are done and the data is archived. It is also displayed on the screen for the scientist operating the laptop.

Sound easy? Turns out it is very difficult to determine with much lead time exactly where a tornado will form - before it does. The challenge is then to surround that area, also before the tornado forms. We found we would not quite guess correctly where the tornado would form, underestimate how far we had to go, or simply not be able to get there in time for whatever reason. Sometimes roads did not cooperate. We won't drive on dirt (usually clay) and we avoid gravel as well. Even if you can make a good guess where the tornado will form it takes time to get a car into position. All this time the storm is moving along doing it's own thing.

We don't stand still for pictures very often and since the storm is moving we have to, too. When roads don't cooperate or are interrupted by rivers, towns, etc., we sometimes have to go out of our way a little bit to stay with the storm. So we're generally moving... but we want that data.

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Last updated: March 25, 2002
Created by: DSZ