GG231 Lecture Notes - Lecture 6: Wind Shear, Vertical Draft, Ice Pellets
Document Summary
Dissipative stage: the final phase of a thunderstorm, when the supply of moist air is blocked by down drafts in the lower levels of the cloud; precipitation decreases and the storm begins to diminish. Mesoscale convective complexities: a large, circular, and long lived group of thunderstorms that interact with one another. Squall lines: narrow band of high winds and storms associated with a cold front. Supercell storms: an unusually long lived thunder storm with rotating updraft on the storms flank lightening. Updrafts and down drafts create patterns or charges that leads to the propagation of the lightning strike. When lightning strikes it warms up the air in its path to temperature as high as 30,000 degrees. This causes the surrounding air to expand rapidly, producing thunder. Most lightening comes from cumulonimbus clouds that have grown high enough for ice crystals to form. These rising ice crystals interact with falling ice pellets creating an electrical field.
