The tornado frequency increases in the spring as the warm and cold seasons battle it out in the U.S.
Warm, humid air surges into the South during the spring months, while colder air remains in place across the northern tier of the country. The clash of warm, humid air and cooler, drier air to the north creates instability for thunderstorms to develop.
Another key ingredient for severe thunderstorm and tornado development is a powerful jet stream, or a corridor of fast winds around the altitude where planes fly. When there are powerful winds high in the atmosphere and weaker winds at the surface, a twisting motion in the atmosphere can help to produce rotating thunderstorms capable of spawning tornadoes.
During the spring months, the jet stream is often still potent across the U.S. before it shifts too far to the north during the summer to support violent storms with tornadoes touching down.
The sun's rays are also strengthening during the spring months, promoting increased daytime heating that further reduces the instability of the atmosphere.
As the sun begins to sink down beneath the horizon Thursday evening, the moon will partially eclipse the fiery star and cast a narrow shadow upon the Earth.
What was an already difficult ridge climb for accomplished ice climber Caroline George had suddenly turned scary and treacherous.
A new moon will allow for the perfect background for the Orionid Meteor Shower, set to peak on Tuesday Oct. 21 and into the morning of Oct. 22.
Showers may make an appearance at several of this year's World Series games in both Kansas City and in San Francisco.
Storms, including Ana, are lining up over the northern Pacific, en route to the northwestern United States and British Columbia.
Attention in the tropics is turning to the swath from southeastern Mexico to Cuba, Florida and the Bahamas, where a new tropical system is budding this week.
Salano's Storm prevented Spanish admiral from attacking Pensacola.
Austin, TX (1984)
$14 million damage from a severe hailstorm. (The storm covered 20 mi. x 5 mi. area.)
Winds aloft and from Hurricane Juan carried African locusts across the Atlantic to Dominica, St. Lucia, Jamaica and five other islands.