Tornado Alley
It has also been asserted that there are numerous Tornado Alleys. In addition to the Texas/Oklahoma/Kansas core, such areas include the Upper Midwest, the lower Ohio Valley, the Tennessee Valley and the lower Mississippi valley. Some studies suggest that there are also smaller tornado alleys located across the United States.
Tornadoes in the United States
In the Southwestern United States, New Mexico reported 485 tornadoes during the 1950 to 2006 period (NCDC figures), California reported 355, Arizona reported 209, and Nevada reported 75. New Mexico borders the notoriously tornado prone states of Texas and Oklahoma, hence the noticeably higher figures. Most of the tornadoes here happen in the very eastern part of the state. New Mexico's region and the desert landscape of the state help prevent the amount of twisters that happen in Oklahoma and Texas. Arizona and New Mexico experience regular summer thunderstorms during their monsoon season. These are sometimes tornadic but rarely produce violent tornadoes.