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

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

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