5What are the types of air masses? TropicalWarm, form in the tropics, have low air pressurePolarCold, form north of 50 degrees north latitude and couth of 50 degrees south latitude (the poles!), high air pressureMaritimeForm over oceans, very humidContinentalForm over land, dry
7What are the four types of fronts? A front is an area where air masses meet and do not mix.WarmColdStationaryOccluded
8What are the four types of fronts? ColdDensecold air mass moves into a warm air mass -> the warm air is pushed upwardClouds form and rain or snow may occurAbrupt (quick) weather, including thunder stormsAFTER: cool, dry air -> clear skies and cooler temperatures
9What are the four types of fronts? WarmWarm air moves over cold airMay cause showers and light rain or scattered clouds, snow in the winterWarm fronts move more slowly than cold air fronts -> may be rainy or foggy for several daysAFTER: warm and humid
10Why does a cold front move faster than a warm front? A cold front moves faster than a warm front because it is easer for a cold (dense) air mass to move the warm (less dense) air mass up and out of the way than it is for a warm air mass to move a cold air mass.
11What are the four types of fronts? OccludedWarm air mass is caught between two cooler air massesWeather may turn cloudy and rainy or snowy
12What are the four types of fronts? StationaryWarm and cold air masses me and do not move one anotherA “standoff”Causes rain, snow, fog, or cloudsMay bring many days of clouds and precipitation
13Tornados, Hurricanes, & Thunderstorms Review p. 108 question # 17Thunderstorms form within large cumulonimbus clouds, or thunderheads.Lightning is a sudden spark, or energy discharge, as charges jump between parts of a cloud or between the cloud and the groundA tornado is a rapidly whirling, funnel-shaped could that reaches down from a storm cloud to touch Earth’s surface.A hurricane is a tropical storm with very strong winds.
17What are isobars and isotherms? Isobars are lines joining places on the map that have the same air pressure.Isotherms are lines joining places that have the same temperature.
18What moves weather across the United States What moves weather across the United States? What direction does it move?
19What moves weather across the United States What moves weather across the United States? What direction does it move?The prevailing westerlies generally push air masses from west to east in North America.
20High and Low air pressure High Pressure – generally good weatherLow Pressure – typically bad or wet weather