PHYS 106L Chapter Notes - Chapter 12: Air Mass, Orographic Lift, Wind Shear
Document Summary
Warm moist air is forced to rise in an unstable atmosphere. Thunderstorms are categorized as air mass thunderstorms or severe thunderstorms. The distinction recognizes that some form in a warm air mass and some require strong vertical wind shear. Occur when maritime tropical air is forced up through orographic lifting, frontal lifting, intense surface heating, or convergence of surface air flow. Seen over great distances but thunder usually isnt heard beyond 30 km. Light travels substantially faster than sound, so we see light before we hear thunder. Sound travels at 340 m/s or miles per second or 1115 ft/s. Arise when air becomes unstable in an already warm and moist air mass. Usually occurs in warmer months where intense surface heating creates instability within maritime tropical air masses. Strong updrafts dominate the circulation within a cumulonimbus cloud, causing the cloud to grow vertically. Precipitation begins and downdrafts develop side by side with updrafts.
