Abstract
Four soundings taken in high-speed updrafts of severe thunderstorms indicate moist adiabatic ascent to mid-levels. This implies that the cores of strong updrafts are undiluted by environmental air. The Squires-Turner entraining jet model substantiates this conclusion. Comparison of model and observed vertical velocities indicates in one case that actual velocities may be reduced by adverse pressure gradient forces which are not included in the model. However, the data from the other cases are not sufficient to verify this hypothesis.
