Comparing the April storm's observed VIL and computed Vrot over time, figure 3 shows that just prior to the tornado over Pickens county (2350-0001 GMT), the VIL began to drop while the Vrot was increasing. From 0001 to 0042 GMT, the VIL increased steadily, then began to fall again after 0042 GMT. The Vrot fell some during the period that VIL was climbing, reaching a minimum near the time the first tornado ended. The Vrot was climbing again and reached its highest value (near or greater than 55 kts) during the time the VIL made its most significant decrease. It was during this dramatic decrease in VIL (0100 to 0124 GMT) that the tornado was most powerful, (F5) on the Fujita Tornado Intensity Scale. The VIL decreased by 40 kg/mē over about a 36 minute time span.