Distinct rotating column beneath wall cloud in connection with the ground
Tornado over water often quite tall and skinny
Severe weather damage
Water vapor condensing into clouds at ground level
Liquid rain freezes to ground and elevated surfaces on contact.
Snow accumulating quickly with low visibility
Wind not associated with convective thunderstorm activity
Ice stones with diameter greater than pea-sized or 0.25"
Clear ice pellets or white graupel, mostly spherical in shape
Light or moderate accumulating snowfall
Thunderstorm wind gust either estimated or measured
Any situation where water is blocking land or roads causing problems
Liquid precipitation (inches)