WEATHER

The weather is the day-to-day condition of the atmosphere at a particular place and time – whether the air is warm or cool, moist or dry, still or moving, and whether rain or snow is falling. METEOROLOGY is the study of the weather. The Sun is the driving force behind the weather. It heats air masses in different parts of the globe unevenly, creating differences in air pressure. This causes winds as air moves from zones of high pressure to low pressure. WEATHER FRONTS occur where moving masses of air collide.

WEATHER FRONTS

Weather fronts are border zones where masses of air of different temperatures and humidity (moisture) levels meet and push into one another. Warm air is less dense, or lighter, than cold air, and so it rises above the cold air. Rising warm air creates an area of low pressure or depression. Depressions are linked with unsettled weather conditions, including high winds and rainy spells.

WARM FRONT

A warm front occurs when a mass of warm air meets a mass of cold air. The warm air slowly rises above the cold air, forming a low pressure zone. As the rising warm air cools, the moisture in it condenses to form clouds, bringing drizzle or rain.

COLD FRONT

A cold front occurs when a mass of cold air is driven towards a mass of warm air. As they collide, a steeply sloping front is formed and the warm air is forced to rise rapidly. This produces towering thunderclouds and brings torrential rain showers.

OCCLUDED FRONT

Cold fronts often follow a few hours behind warm fronts. Earth’s rotation bends the moving masses of air, causing the fronts to spiral around one another. The warm and cold air merge to form an occluded front, which brings cloudy skies and rain.

METEOROLOGY

Meteorology is the study of atmospheric conditions and weather systems. Meteorologists have the difficult task of predicting the weather for the next few days (short-term forecasts) and for a week or so ahead (long-term forecasts). We all rely on weather forecasts to help plan the day, but they are particularly important for farmers, shipping firms, and airlines, and also power stations, since the weather affects the amount of energy we use.

WEATHER MAP

A synoptic chart, or weather map, shows conditions in the atmosphere at a particular place and time – here, the weather system northeast of Japan in the satellite image above. Atmospheric conditions are shown using internationally known symbols. Lines called isobars link areas of equal air pressure.

WEATHER SATELLITES

Scientists use satellites orbiting high above Earth to track weather systems. Satellites provide images of clouds, storms, and hurricanes. They also monitor temperatures and humidity using sophisticated sensors.

Copyright © 2007 Dorling Kindersley

stay connected

Sign up for our free email newsletters and receive the latest advice and information on all things parenting.

Enter your email address to sign up or manage your account.

Facebook icon Twitter icon Follow Us on Pinterest

editor’s picks

highlights

Join BIC on our mission to save handwriting and Fight For Your Write! Writing helps kids become better readers, boosts their confidence and sparks their creativity. Visit BICFightForYourWrite.com to sign our petition to save handwriting!

7 Fun Driveway and Sidewalk Games for Kids
Looking for classic outdoor games kids can play in the driveway or on the sidewalk, just like the good ol' days? From hopscotch to bubble-blowing contests, there's something for all ages!

Kindergarten Readiness App Wins Gold
Our Kindergarten Readiness app won the Gold Award of Excellence in the educational category at the 2014 Communicator Awards. This valuable checklist comes with games and activities to help your child practice the essential skills she needs for kindergarten. Download the Kindergarten Readiness app today!

Best Sun Safety Practices for Babies
Follow these sun safety practices for babies to ensure your little one stays safe on the beach and on sunny days all year long.