What do they see on Doppler radar–what are they looking for and how do they tell if there is a tornado forming?
Tornadoes are too small to be resolved on 88D radar, so meteorologists look for the larger circulations that precede a tornado. “Doppler radar screens show “reflectivity” and “velocity”. The image here is for reflectivity. The colors on the reflectivity radar screen shows the intensity of the rainfall. This image shows the velocity radar screen. It shows which way the wind is blowing in relation to the Doppler radar. Green means that the air is moving “inbound” towards the Doppler; red means that it is moving “outbound” away from the radar. If the entire storm is moving towards the radar, there would be lots of green. If the entire storm is moving away from from the radar, there would be lots of red. When the meteorologists examine the Doppler radar image, he or she looks for a place where bright red(the “outbound”) and bright green(the “inbound” color) are positioned next to one another. This denotes some rotation inside the supercell–the mesocycone, which may be spawning a tornado.
