When are tornadoes most likely to occur?
Think about it. During which season of the year would a warm moist maritime tropical air mass collide with a cold dry continental polar air mass over North America?
Source: http://www.nssl.noaa.gov/noaastory/chap1.shtml |
Look carefully at the diagram. Warm moist air is moving north from the Gulf of Mexico. Note the warm front. Cold dry air is moving south and east along the Rockies. Note the cold front. Upper level shearing winds generate a counterclockwise spin at the point labeled L for low pressure. Tornadoes are triggered when a supercell thunderstorm forms. |
 |
Hint: In North America, the number of hours of daylight will be increasing. Increasing radiant energy will warm the waters of the Gulf of Mexico. Air moving south from Canada and east from the Rockies will still be cold and dry. Check it out: View map of tornado occurences. |
Source: http://liftoff.msfc.nasa.gov/News/Default.asp?whichpage=10
