Tornado cyclone
From Glossary of Meteorology
tornado cyclone
A term coined by Brooks (1949) to describe a surface low pressure area in a convective storm that, with its attendant winds, has a radius of about 8–16 km and is associated with, but is larger than, a tornado.
Starting with Agee (1976), the tornado cyclone has been redefined as a distinct circulation with a scale larger than that of the tornado but smaller than that of the mesocyclone (although embedded within it and smaller in scale than the mesolow). The intermediate-scale tornado cyclone is sometimes inferred from high-resolution Doppler radar observations, but at other times it is not apparent.
Brooks, E. M. 1949. The tornado cyclone. Weatherwise. 2. 32–33.
Agee, E. M. 1976. Multiple vortex features in the tornado cyclone and the occurrence of tornado families. Mon. Wea. Rev.. 104. 552–563.
