AIR MASSES A large body of air (thousands of miles) Changes in weather are caused by movements of air masses As an air mass moves away, temp & humidity.
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Presentation on theme: "AIR MASSES A large body of air (thousands of miles) Changes in weather are caused by movements of air masses As an air mass moves away, temp & humidity."— Presentation transcript:
A small storm often accompanied with heavy precipitation & thunder & lightning. Form in large cumulonimbus clouds called thunderheads.
On hot, humid days, warm air rises rapidly, & cools forming cumulonimbus clouds. This movement of air creates updraft & downdraft winds.
Areas of (+)/(-) charges build up in storm clouds. It is a sudden discharge of electricity between 2 clouds or the cloud and the ground. Electric energy is released.
Light travels faster than sound. Lightning heats air. Heated air expands rapidly which results in sound waves (thunder).
T-Storm Damage Heavy rains which can lead to floods. Lightning, Hail, & winds can cause damage.
Whirling, funnel shaped cloud that reaches down from a storm cloud to touch earth’s surface. Warmth & Moisture feed it Season: late spring/early summer
Warm, humid air meets cold, dry air. A squall line of thunderstorms develop which can develop into a tornado. Warm air rises rapidly & begins to rotate. The cloud will then start to descend to earth in a funnel.
Tornado Alley- Mid-West US This is where the conditions are the best- warm, humid air from Mexico mixes with cold, dry air from Canada.
Tornadoes occur most frequently in the US Damage comes from strong winds & flying debris.
Tornadoes are ranked on the Fujita Scale (by the amount of damage they cause.) F0 light damage to F5 extreme damage. F4 F5 tornadoes account for only 1% of all tornadoes.
A tropical cyclone that has winds of 119kmh or higher. Forms in the Atlantic, Pacific, & Indian Oceans. In western Pacific- typhoons.
HURRICANE FORMATION It begins over warm ocean water as a low-pressure area (tropical disturbance). It grows from a disturbance to a tropical storm and maybe to a hurricane.
It draws energy from warm, humid air at ocean’s surface. Warm air rises to form clouds, more air is drawn into the system. Storms bands, high winds, & heavy rains spiral around a center.
Cool, dry air sinks into the center (eye) of the hurricane. Hurricanes last longer than other storms- usually a week or longer.
Lines joining areas with the same air pressure.
TECHNOLOGY Has improved the accuracy of weather forecasts. Weather balloons carry instruments into the troposphere & stratosphere to measure temp., air pressure, & humidity.
Weather Satellites- orbit earth in the thermosphere, cameras make images of the earth’s surface, clouds, & storms which get sent to meteorologists to analyze.
Computer Forecasts- gathers weather data from a large area then the computer works through thousands of calculations using equations from weather models to make forecasts for 12, 24, & 36 hours. Each one builds on the previous forecasts.