FRONTS 24-2
Fronts When 2 air masses meet density differences keep them separate Front- boundary between air masses 100’s to 1,000’s of miles wide
Cold Front Cold air mass overtakes a warm air mass Cold air lift warm air up Short lived Violent
Squall line – long line of heavy thunderstorms
Warm Front Front edge of an advancing warm air mass Cold mass retreats from an area Precipitation over a large area
Stationary Front Fronts either move very slow or don’t move
Occluded Front Cold air mass overtakes warm air mass Lift warm air up above
Polar Front Cold polar air meets warm tropical air
Midlatitude Cyclone Low pressure Rotating wind Moves towards the rising air of central low pressure regions
Midlatitude Cyclone Stages
Anticyclone Air sinks and flows outward from a center of high pressure Clockwise in NH Dry weather
Thunderstorms Heavy storm with rain, thunder, lightning, and winds 3 stages: 1. Cumulus – warm moist air rises 2. Mature – dark cumulonimbus (heavy rain) 3. Dissipating - end
Lightning Clouds discharge electricity Rapid expansion of air – thunder Lightning fun facts!
Hurricanes Tropical oceans 120 mph winds in a spiral Intense low pressure
Winds increase towards the center – eye Eye – calm sinking air Storms surge – rising sea level
Safir-Simpson Scale
Tornadoes Rotating column of air High winds Funnel-shaped 400 km/hr Thunderstorm meets a high altitude horizontal wind
Tornado Alley