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Simple answers to... How do you see a tornado on radar and how do you know if a tornado is coming toward you?

When the cross section of precipitation makes a hook shape, or a hook echo, we can infer strong rotation and possibly a tornado.  Precipitation is revealed in the "reflectivity" mode on radar apps.

In Reflectivity mode, some of the beam emitted from radar is reflected back to the radar by rain, snow or hail and detected. That’s why we call it an echo. 

The greatest reflectivity comes from hail stones displayed in pinks and purples and the smallest the more tiny hydrometeors like light rain and drizzle in yellow or green.

Not all tornadoes form a hook echo o radar. That's were "Velocity" mode comes in. Velocity mode is like X-ray vision. 
It’s a POWERFUL tool for detecting circulations within a storm.  
Red indicates wind moving away from the radar, and green toward the radar.   A relatively small concentrated area of inbound and outbound stronger velocities coming together indicates strong rotation and possibly a tornado. Together, Reflectivity and Velocity are powerful tools for detecting tornadoes. 

Tornadoes often change direction and the scan you are viewing could be several minutes old. Also factor in, the circulations depicted on radar can be several kilometers aloft. And the tornadoes position at the surface can be displaced as it bends diagonally through the storm.

Many radar apps like Radarscope have a storm tracking or cell motions option. You can also get a good idea of what direction the storm is going by playing the animation loop.

Some radar apps also offer lightning data. Most of the time lightning data is a good tool for tracking lightning and predicting storm intensity.   I assumed they are all lightning data is detecting cloud-to-ground lightning strikes, but to be honest, there are many times when I’m positioned in a sea of would-be lightning strikes according to the data, and I’ve observed no CG’s near my area.  So perhaps they were false signals or large intra-cloud discharges were detected? I’m currently looking into this mystery. 

On May 1st, I witnessed my first tornado of 2018 near Salina Kansas. Watch how I use radar to track the tornado.

All footage copyright Pecos Hank 2018
Outro music "Crossed the Line" by Southern Backtones