Forecasting Weather After completing this section, students will analyze weather maps and the resulting regional weather (Standard PI – 061)

To prepare accurate weather forecasts, meteorologists must gather, distribute and analyze huge amounts of atmospheric data

Weather data can be collected by: Satellites Weather Balloons and Radiosondes Weather Stations Weather Radar Airplanes and Ships

Satellite images provide weather information about about every spot on the Earth Meteorologists use 2 kinds of satellite images, visible images and infrared images

Visible satellite images are black and white pictures of the Earth White colors represent clouds or snow, grey represents land and black is water

By tracking the movement of clouds, meteorologists can estimate wind speed and direction and track storms One disadvantage of visible satellite images is that they are not available at night

Infrared satellite images use temperature to create pictures Infrared images can be taken day or night

Bright areas represent cold temperatures and cold high tops of clouds Dark colors represent warmer temperatures and low clouds

The taller the cumulonimbus clouds, the stronger the storm By looking at cloud height (as represented by color) meteorologists can determine the severity of a storm The taller the cumulonimbus clouds, the stronger the storm

Radiosondes – an instrument pack attached to a balloon which carries it up into the atmosphere Meteorologists use radiosondes to measure temperature, humidity and pressure at different altitudes

Information from radiosondes can be used to predict how air masses might move

Weather Stations A device for measuring temperature, air pressure, dew point, wind speed and direction and precipitation

Weather station report conditions about every hour Only by analyzing data from weather stations can meteorologists decide where in a storm it is raining, or snowing Weather station report conditions about every hour

Station Models (Modelo de estación)

Using the data they get from weather stations, meteorologists create weather maps

To fit large amounts of data onto a compact map, scientists have developed the station model A station model includes information on temperature, dew point, weather conditions, wind speed and direction

Making a Surface Weather Map

It takes several steps to make a surface weather map First a computer draws a map showing station models connecting areas of equal air pressure (isobars) and temperature (isotherms)

Meterologists then draw in fronts based on where low pressure systems are located

Modern-day weather forecasts are based on computer models They use observed data such as, temperature, wind speed and direction, and plug it into a mathematical equation to make predictions