Hail in Texas, April 22, 1996

Synopsis for evening of April 21 and early morning of April 22: A cold front which had pushed south through the Permian Basin on the 20th began to return northward as a warm front during the evening of the 21st in response to a short-wave trough approaching West Texas in a moderately strong southwesterly mid-level flow. Shortly after 7pm CDT, a southward moving surface boundary collided with the warm front, which was now over Upton and Glasscock Counties. By 10pm, convection was initiated over Central Upton and southern Glasscock counties. Initially the cells moved with the mean flow along the warm frontal boundary, however by about midnight two cells in the northern half of Upton County developed supercellular characteristics and began to move to the right of the mean wind. The two supercells moved east into northern Reagan County producing hail between 1.75 and 2.00 inches. Meanwhile, a third supercell developed in northeastern Glasscock County at approximately 1250 am and moved quickly into Sterling County. By 150 am, outflow boundary interactions reinitiated convection over Northern Upton county with additional convective development further southwest over Northern Pecos county. These cells quickly became outflow-dominated and merged together to form a mesoscale convective complex. This complex increased in areal coverage as it moved northeast over Upton and Reagan counties producing hail of up to 1.75 inches in diameter.