WEATHER IS THE TERM WE USE TO DESCRIBE THE CONDITIONS OF THE ATMOSPHERE AROUND US. What is Weather?

Weather – Four Main Elements Temperature Moisture Wind Air The interaction of these ingredients is what makes our weather

Temperature The degree of hotness or coldness measured Thermometer  Fahrenheit:  Freeze at 32 degrees  Boil at 212 degrees  Celsius: (internationally accepted)  Freeze at 0 degrees  Boil at 100 degrees

Moisture The amount of water vapor in the air When the air is holding the maximum moisture we say the air is saturated The point where air is saturated is the dew point

Wind Air movement Caused by the uneven heating of the earth’s surface Warm air rises Measured by an anemometer

Air and Air Pressure The weight of the atmosphere pushing down Temperature differences cause changes Barometers measure air pressure

Air and Air Pressure All weather occurs in the bottom layer of atmosphere 6 miles high Weather systems move because of energy from sun Wind always blows from high to low pressure Sun Heats Ground Ground warms air above Warm air rises causing low pressure on the ground Cooler air rushes in, gets warm and rises Warm air rising cools off, and sinks causing a high pressure

High and Low Pressure

Low pressure brings strong wind, clouds and rain High pressure is dry, some clouds  Winter: cold weather, few clouds so ground heat escapes  Summer: good weather, few clouds block sun Equator: air warm and light = low pressure North and South: pressure higher

Climate Average weather of a location Four Ways Climate is Affected 1. Distance from equator determines temperature 2. Ocean currents impact climate  Inland: cold winter & hot summer  Coastal: cool winter & mild summer 3. Height above sea level  Higher elevation is cooler 4. Average Rainfall

Wild Weather Tornados and Hurricanes Blizzard Flood Drought Thunder and Lightning

People and Weather Meteorologists are scientists who study weather Weather forecasters predict future weather