Predicting the Weather

Weather Forecasting A weather forecast is a prediction of the weather. You use weather forecasts to decide what to wear each day and what activities you can participate in. Scientists use tools to measure the current weather to help make their predictions about future weather.

Weather Maps Weather maps can show what the weather was like in a place on a certain day. Scientists use data from weather stations all over the world to create weather maps.

Weather Maps and Symbols Click the link below to see an explanation of weather maps: https://www.youtube.com/watch?v=9NZz-EeveJ8

Air Masses There are 4 basic types: Weather maps show the movement of air masses. An air mass is a large body of air with about the same temperature and humidity throughout. There are 4 basic types: Cold and Dry - Warm and Dry Cold and Humid - Warm and Humid

Fronts Weather Maps also show fronts. A front is a place where 2 different air masses meet. Click below to learn more about air masses and fronts: http://studyjams.scholastic.com/studyjams/jams/science/weather-and-climate/air-masses-and-fronts.htm

Cold Front Warm Front Stationary Front Occluded Front Cold air mass bumps against warm air mass Strong storms happen here (thunderstorms in warm weather, snowstorms in winter) Causes temperature in an area to drop. Warm air mass meets colder air mass and rises over it Stratus clouds form which often bring rain Causes temperature in an area to rise Forms when 2 air masses meet and stop moving Bring clouds and precipitation lasting longer because air masses are not moving An occluded front is a combination of two fronts that form when a cold front catches up and overtakes a warm front.

Air Pressure Air pressure is measured with a barometer. Low air pressure usually brings rainy or stormy weather. High air pressure usually brings fair weather.

Weather Patterns in the United States In the United States, weather usually moves from WEST to EAST. Rain forming over the Pacific Ocean moves east over California and weather forming over the middle of the U.S. often moves towards North Carolina and other eastern states within days. WEST to EAST