Introduction to Weather Ms. Cervera

Bellringer # 1 Windsurfers harness the power of the wind to skim their boards across the water. Windsurfers pay attention to many weather factors, not just the wind. They might choose to stay off the water during cold or rainy weather or when a storm is on its way. Describe at least three weather factors that you observe in this image.

Today’s Learning Objectives Students will be able to… Identify and describe the different variables used to describe weather Explain the relationship between air pressure and the density of air

What is Weather? Weather is the atmospheric conditions, along with short-term changes, of a certain place at a certain time. Temperature and rainfall are just two of the variables used to describe weather. Meteorologists use a variety of variables to predict weather, including air temperature, air pressure, wind speed and direction, humidity, cloud coverage, and precipitation.

Weather Variables: Temperature Air temperature is the measure of the average kinetic energy of molecules in the air. Molecules in warm air move faster than molecules in cold air. Temperature is measured in degrees. The temperature scale used by scientists is the Celsius scale.

Weather Variables: Air Pressure

Weather Variables: Air Pressure Air pressure is the pressure that a column of air exerts on the air, or surface, below it. The air pressure at any particular point on the Earth depends on the density of the air. Air pressure is measured with an instrument called a barometer. As air moves from areas of high pressure to areas of low pressure, it creates wind.

Winds Warm air has a lower density than cool air. Warm air rises and produces an area of low pressure, while cold air produces an area of high pressure As air moves from areas of high pressure to areas of low pressure, it creates wind. Meteorologists measure wind speed using an instrument called an anemometer.