ESCI 1012 Lecture Notes - Lecture 21: Great Natchez Tornado, Supercell, Mesocyclone
Document Summary
Most often form from powerful thunderstorms (supercell thunderstorms) or hurricane systems. First historical record of us tornado- june 1648. A (cid:907)great te(cid:289)pest(cid:908) with dow(cid:290)ed trees close to hartford, co(cid:290)(cid:290)ecticut. 219 mile track through missouri, illinois and indiana. Most of the deaths were on the river where boats were capsized. No slaves were recorded as human deaths, slaves were considered property loss, politics play a role again. Death toll was higher due to high population density. Only f1 or f2 tornado but due to poor housing it led to a high death toll. Us leads the world in number of tornadoes. They can occur almost anywhere though, 1200 a year. North america extends from tropics to arctic without any east-west mountain ranges to block air flow. Cold air from canada and hot air from the tropics. Rocky mountains blocks the pacific moisture and creates a low-pressure system to east of mountains that eases updrafts.
