world, agricultural areas (e.g., the midwestern United States and farming
regions within other countries like Brazil and Argentina) tend to be at
higher risk for the development of tornadoes because certain weather
patterns that promote good crop yields may also contribute to the
development of tornadoes (10). In addition to geographic factors, the
time of day and the time of year also affect a population's risk from
tornadoes. For example, late afternoon is the time of day when tornadoes are
most likely to occur. Seasonal variation associated with the development of
tornadoes means that the risk from tornadoes to the population at any given
location is not constant throughout the year. In the United States, January
is the month when the fewest tornadoes occur, and May is the month when the
most tornadoes occur (10). Other natural factors that promote the
development of tornadoes include weather phenomena such as hurricanes.
Hurricane Beulah, for example, which struck in 1967, is credited with
spawning 115 tornadoes in the coastal region of Texas (2).