A method of estimating the velocity of severe thunderstorms

Ludlam's (1961) severe local storm model is extended to three dimensions. Using this modified model, the vertical wind profile in the environment of the storm between the surface and 450 mb and a new hypothesis, the velocity of thunder-storms in their severe stage may be estimated. In a test using nine SH storms the method of this paper compared favourably with other methods of estimating severe storm velocity. It is suggested that the vertical wind profile in the environment of the storm determines whether it, in becoming severe, evolves to an SH, SL or SN type. Storm pairs resulting from the splitting of a single storm may be an exception. A severe storm's intensity may also be estimated. A storm which develops in a wind profile where |V~M|<|V~L| has an updraft which originates from behind the storm and a downdraft which is fed from the front of the storm.