Anonymous
Anonymous asked in Science & MathematicsWeather · 9 years ago

how do u know where a tornado is or will be on a radar?

where it will touchdown

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  • Anonymous
    9 years ago
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    A doppler radar can not see a tornado. Doppler radar uses RF signals that beam out and bounce off any particles, rain drops, hail, or snow that may be in the atmosphere.

    With that being said, a good way to know if there is low level rotation within a storm is to look at the lowest radar scan in Base Reflectivity product and also in Storm Relative Velocity product.

    In BR product, if there is significant low level rotation, the doppler radar may show what looks like a comma. This is known as a "hook echo". This is where any particles(rain, hail) has gotten caught up in the rotation and shows up on the radar. Here is an actual doppler radar image of a hook echo in BR product. http://upload.wikimedia.org/wikipedia/commons/thum...

    In Storm Relative Velocity product, you are seeing the wind speeds towards and away from the radar site. Green color indicated winds towards and red indicated winds going away from the radar site. Brighter colors indicate higher wind speeds. When these brighter reds and greens are close to each other, this indicates significant high winds. Here is a photo of such http://www.erh.noaa.gov/rlx/science/101106/image00...

    Source(s): Storm spotter/chaser
  • 9 years ago

    First, it will most likely be in the areas of the radar image that is the most severe (usually, this is red or hot pink, less severe is yellow, then green, etc). Then you're looking for what they call a hook echo, which indicates strong rotation. It basically looks like anything from a comma to nearly a complete circle.

    Now, this is only an indication that a tornado is occurring or is imminent. It doesn't necessarily mean that there is currently a tornado on the ground. The only way to make that determination is to actually observe the tornado. However, it's enough for forecasters to issue a tornado warning.

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