Weather+Forecasting

= __ Gathering Weather Data __ =

In order to predict the weather, experts constantly gather information about weather conditions everywhere. This information, called instrumental data, is collected using specialized equipment.

Weather Stations
In a weather station, meteorologists use instruments to monitor wind speed, visibility, pressure, air temperature and rainfall. They also observe and record general weather conditions, such as fog and cloud type. Find out what goes on at the Mount Washington Observatory. (Scroll down and click on the link for "Pitot Anemometer and Wind Direction" and other headings for links to video clips on weather forecasting.) []

Weather Balloons
Instruments called radiosondes measure temperature, air pressure, and humidity at different heights above the ground. They are carried into the air by weather balloons. The speed and direction of the rising balloon show the strength and direction of the wind. The radiosonde takes readings as it rises and transmits them to a weather station on the ground. The balloon bursts when the air pressure surrounding it is less than the pressure inside. A small parachute drops the radiosonde gently to the ground.

Weather Satellites
Weather satellites orbit Earth, collecting information about global weather conditions. There are two main kinds of satellites: polar-orbiting and geostationary. Find out more about weather satellites at this interactive website: []

This website is a colorful, animated and interactive site that shows you how satellites work and what they do. []

//Geostationary satellites stay in the same position over the Earth by orbiting at the same speed as Earth rotates.//

Radars
Weather radars indentify areas of rain, snow or hail, and how heavily they are falling. A doppler radar, shown below, also detects the speed and direction of moving wet weather. //Antenna sends out radio waves. If the waves hit stationary water drops, dust or ice crystals, they bounce back to a receiving dish at the same speed as they came out//.