Wall Cloud Definition - A localized, persistent, often abrupt lowering from a rain-free base. Wall clouds can range from a fraction of a mile up to nearly five miles in diameter, and normally are found on the south or southwest (inflow) side of the thunderstorm. When seen from within several miles, many wall clouds exhibit rapid upward motion and cyclonic rotation. However, not all wall clouds rotate. Rotating wall clouds usually develop before strong or violent tornadoes, by anywhere from a few minutes up to nearly an hour. Wall clouds should be monitored visually for signs of persistent, sustained rotation and/or rapid vertical motion.
On Kansas/Nebraska border. Photo by Tornado Tim
Haven, Ks March 13, 1990, Photos by (Matt Dennis)
Near Sedgwick, Ks April 9, 1990. Photos by (Matt Dennis)