Can speed shear ever be too high? You would think that the higher the speed shear with height, the greater the chance would be for supercells to develop in an unstable environment. This is true in some cases, but not in others. A few times when I was in Oklahoma I ran into cases where the wind shear was too high. The developing storm broke the cap and began to climb into the mid-levels of the atmosphere. But, the mid and upper level winds were so strong that it blew the top off the developing storm (basically shredded it in half, not just tilted it, but chopped it).

When speed shear is very high, very high CAPE is also needed. An intense updraft (i.e. 100 miles per hour) is less likely to be chopped in half than a weaker updraft. The size of the updraft is also important. Large intense updrafts are less likely to be chopped in half. Updrafts in a high speed shear environment can be described as "survival of the fittest updraft" since only the strongest and largest updrafts can handle extreme speed shear; These updrafts can become monster storms. If the CAPE is marginal and the speed shear is extreme (e.g. CAPE = 400 J/kg, PBL wind = 20 knots, 700 mb wind = 90 knots, 500 mb wind = 120 knots, these days may result in no storms (no updraft can take it, they are shredded to pieces).