A description is given of a tornado which occurred in the Tarnagulla - Laanecoorie area, 100 miles north of Melbourne, on 27th September 1964. This was compiled from eyewitness accounts and inspection of damage carried out two days later. The synoptic situation and stability of the atmosphere on the day of occurrence are discussed, in particular the modification which may take place in air mass structure during the six hours after a radiosonde ascent.
D. J. Linforth (Tue,) studied this question.