The Wmax Equation
One reason why CAPE is such a useful parameter for forecasters is that CAPE is directly related to the maximum potential speed of the updraft, or Wmax, as shown by this equation. This equation is derived from a simplification of the vertical momentum equation by ignoring mixing, water loading, and pressure effects. In reality, these simplifications mean that Wmax often overestimates the actual updraft value by a factor of 2.
Using this equation, a relatively high CAPE of 2000 J/kg would indicate a Wmax of 63.2 m/s, or, allowing for the overestimate, a more probable Wmax of 31.6 m/s, or about 65 knots.