EARTHSC 2GG3 Chapter Notes - Chapter 10: Hook Echo, Wind Shear, Wall Cloud
29 Dec 2019
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Document Summary
Temperature related events cause the most deaths on average per year. Supercell is much larger than a single cell and may rotate. Updraft and rotation can lead to tornadoes. Rotation coming from wind shear (horizontal wind movement) Combination of updraft and horizontal wind shear causes rotation. Not all supercells form tornadoes but most tornadoes are formed from supercells. Difficult to predict which supercells will produce a tornado. Single cells only have vertical movement of warm air. Core of tornado vortex is usually 1 km wide. Overall more powerful than hurricanes but affect smaller areas. Eastern and central north america has flat land, strong westerlies, and combination of warm moist gulf air + cold dry northern + western air some parts of canada are still at risk. Us hosts 70% of tornadoes on earth, good conditions and meeting of 3 air masses. Markedly lower cloud beneath main mass of mesocyclone aka pedestal cloud. Form in supercells where updrafts are the strongest.
