Here is an image of the radar pilots use.
You can see that storms are very clear, and the colours tell you how bad the storm is likely to be.
Green is light turbulence.
Amber is moderate
Red is dangerous and to be avoided.
You can also see other things:
Speed 313 mph (GS = groundspeed) TAS = true airspeed
Range 10/15 nautical miles - the storm is 8 miles away in this picture
Wind 236 degrees (south west) 15 miles per hour
Another plane off to the right 10 miles away and 1900 feet above/ Plane direction 340 degrees (North West)