Chapters 6-?

• cirrus clouds are a high cirriform cloud with a feathery appearance
• clouds are a visible accumulation of tiny liquid water droplets or ice crystals suspended in the atmosphere
• convective lifting is air lifting with showery precipitation resulting from convection
• convergent lifting is air lifting as a result of wind convergence
• cumulonimbus clouds are tall cumulus clouds associated with rain, thunderstorms, and other kinds of severe weather, such as tornadoes and hurricanes
• cumulus clouds are puffy white clouds that form from rising columns of air
• lifting condensation level (LCL) is the altitude at which rising air cools sufficiently to reach 100% relative humidity level at the dew point temperature, and condensation begins
• orographic lifting is an uplift process that occurs when air is forced to rise over topographic barriers
• precipitation occurs when drops of liquid or solid water fall from clouds
• stable air is air that rises only if forced
• stratus clouds are layered, horizontal clouds often below altitudes of 2 km
• unstable air is air that rises without being forced
• an air mass is an extensive body of air that has relatively uniform properties in the horizontal direction and moves as a single entity
• a cold front is the leading edge of a cool air mass actively displacing warm air
• cyclogenesis is the process of formation of cyclones
• an easterly wave is a long but weak migratory low-pressure trough in the tropics
• the Enhanced Fujita Scale is a classification scale of tornado strength with EF-0 being the weakest tornadoes, and EF-5 being the most powerful
• the eye of a tropical cyclone is the non-stormy, calm center of a cyclone with a diameter of 16-40km
• a front is a sharp zone of discontinuity between unlike air masses
• a funnel cloud is a funnel-shaped cloud extending down from a cumulonimbus cloud; a tornado forms when it touches the surface
• a hurricane is a tropical cyclone with wind speeds of 119 km/hour or greater affecting North America and Central America
• lightning is a luminous electric discharge in the atmosphere caused by the separation of positive and negative charges associated with cumulonimbus clouds
• a mesocyclone is the cyclonic circulation of air within a severe thunderstorm a diameter of about 10km
• a midlatitude anticyclone is an extensive migratory high-pressure cell of the midlatitudes that moves generally with the westerlies
• a midlatitude cyclone is a large, migratory low-pressure system that occurs within the midlatitudes and moves generally with the westerlies; also called extratropical cyclone or wave cyclone
• an occluded front is a complex front formed when a cold front overtakes a warm front, lifting all of the warm air mass off the ground
• occlusion is the process of a cold front overtaking a warm front, forming an occluded front
• the Saffir-Simpson Hurricane Scale is the classification system of hurricane strength with category 1 being the weakest and category 5 being the strongest
• a stationary front is the common boundary between two air masses in a situation in which neither air mass displaces the other
• a storm surge is a surge of wind-driven water as much as 8 meters above normal tide level, occurring when a hurricane advances onto a shoreline
• a storm warning is a weather advisory issued when a severe thunderstorm or tornado has been observed in an area
• a storm watch is a weather advisory issued when conditions are favorable for strong thunderstorms or tornadoes
• thunder is the sound resulting from the shock wave produced by the instantaneous expansion of air abruptly heated by a lightning bolt
• a thunderstorm is a violent convective storm accompanied by thunder and lightning
• a tornado is a localized cyclonic low-pressure cell surrounded by a whirling cylinder of violent wind, characterized by a funnel cloud extending below a cumulonimbus cloud
• a tropical cyclone is a storm affecting the tropics and subtropics characterized by a circular, intense low pressure center
• a tropical depression is a tropic cyclone with winds less than 33 knots
• a tropical storm is a tropical cyclone with winds 34-63 knots
• a warm front is the leading edge of an advancing warm air mass
• a waterspout is a funnel cloud in contact with an ocean or large lake, similar to a weak tornado over water