21.   On Wednesday, severe thunderstorms spawned numerous tornadoes across central and northern Florida.

22.   Shifting winds will impart rotation to some of the thunderstorms, which may spawn a few tornadoes.

23.   The Pacific disturbance that spawned tornadoes over California earlier this week was able to produce the severe weather in spite of a modest supply of low-level moisture.

24.   The same vigorous jet stream has energized violent thunderstorms that have spawned tornadoes farther east.

25.   The severe thunderstorm that spawns a tornado can be much more long-lived.

26.   The storm was part of a system that rumbled across much of Texas, spawning a tornado that damaged a school in Anderson County.

27.   These rotating storms, called supercells, may spawn isolated tornadoes.

28.   These could spawn several tornadoes.

29.   These rotating storms, known as supercells, could spawn isolated tornadoes.

30.   These rotating storms, called supercells, can spawn tornadoes.