subject: How Wireless Weather Stations Forecast The Weather [print this page] Wireless weather stations are devices that contain mechanisms to note the data required to forecast the weather, and a microchip to interpret the information and a variety of styles of presentation display to explain the ensuing weather forecast. The instrument will incorporate thermometers to measure inside and outdoor temperature, a rain gauge to calculate amount of rainfall, a barometer to measure barometric pressure, a hygrometer to determine humidity, an anemometer for wind velocity and wind vanes for wind bearing.
Nearly all current weather stations are wireless, allowing you to easily put the remote containing the instruments on the outside and position the base unit easily inside. A number contain built in atomic clocks which are remotely calibrated frequently to keep them on time, and many display icons advising you if you would be advised to carry an umbrella with you or how you should dress for the day.
To appreciate how the the weather forecast is created you need to understand how the weather is formed. The land and sea of our planet are heated by the sun to different extents. It is the variation in temperature at different places that initiates the winds that bring about the weather.
When the land or sea is warmed the warmer air above it goes up, so giving rise to a region of low pressure, as the air cools it descends and gives rise to an area of high pressure. As the air climbs it swells and cools down, and since cooler air holds a smaller amount water than warmer air, the water condenses and forms clouds. As the air sinks it shrinks and heats up and so can hold more water than cooler air. Accordingly a zone of low pressure is linked with rain clouds and consequently rain, and high pressure with dry, fair weather.
Winds are caused by air moving from high to low pressure regions, but the effect of the rotation of the earth and resistance as the air moves across the ground force the winds to stream around the centres of the low and high pressure regions, instead of in a straight line between them. The force of the wind is in proportion to the variation in air pressure between the low and high pressure regions.
An area of low pressure is known as a depression and an area of high pressure an anticyclone. A front is formed where a depression comes up against an anticyclone, and is usually linked with cloud and rain as the less warm air causes the water in the warmer air to condense.
So determining the air pressure, humidity, wind speed and temperature at a distinct location over a time period will show if depressions or anticyclones are taking place and if they are crossing an area, enabling a prediction of how the weather will perform in the coming day and allowing the weather station to tell you whether you should get dressed warmly or bring an umbrella with you.
