Abstract
The tornadoes of January 21, 1959, in Tennessee and neighboring States are considered in relation to the New England January thaw singularity described by Wahl [1]. This singularity, in the form of a warm spell, is shown to occur on the average on January 20–22 at Nashville. It is shown that at the time of the singularity there coexist on the average in the Tennessee area certain conditions favorable for the formation of severe storms. These include a tongue of warm, moist air at the surface, a wind shift from southerlies during the warm period to cool northwesterlies immediately afterward, a 500-mb. trough to the west with southwesterly winds and contour inflection point over the Tennessee area, and the presence of a jet stream aloft. Review of past records reveals that tornadoes in the Arkansas, Alabama, Mississippi, Tennessee, and Kentucky area have occurred more often during the time of the singularity, January 20–22, than at any other time of the month.
