What Are Air Masses and Weather Fronts?

What Are Air Masses and Weather Fronts? — page 1 — LET’S TALK ABOUT THE WEATHER People are always curious about the weather We want to know if it will be warm or cold sunny or rainy This helps us decide what to wear It also helps us plan what to do Another reason we talk about the weather is because it is always changing It can be sunny when we wake up but raining by lunchtime Weather can change quickly for many different reasons But even when it does you can be ready for it 4

What Are Air Masses and Weather Fronts? — page 2 — People who study the weather are called meteorologists Some of the most important things meteorologists study are weather fronts A weather front is the area between cold and warm bodies of air called air masses Watching weather fronts helps meteorologists forecast what the weather will be And that helps people plan better One of the things meteorologists do is watch developing storms They gather information and warn people if the storm is becoming dangerous Forecast means to predict the weather based on observations of weather conditions 5

What Are Air Masses and Weather Fronts? — page 3 — Weather is a mix of ﬁve different features The ﬁrst feature is temperature meaning how warm or cold it is outside Wind the movement of air on Earth is the second feature Next is humidity the amount of moisture in the air High humidity makes us feel wet and sticky Dry air has low humidity The fourth feature of weather is precipitation Rain hail sleet and snow are types WHAT IS WEATHER Thermometers show how warm or cold it is Hygrometers measure humidity The instrument shown here combines both functions 6

What Are Air Masses and Weather Fronts? — page 4 — of precipitation The ﬁnal feature is atmospheric pressure Atmospheric pressure is the weight of the air Changes in atmospheric pressure help meteorologists predict weather Falling pressure means rain is on the way Rising pressure means nice weather is coming Snow can be dry or wet Dry snow won’t stick together to form a snowball Wetter snow is perfect if you want to build a snowman Water freezes when it gets very cold How do different temperatures change the type of precipitation that falls THINK ABOUT IT 7

3

PAGE 3 OF 29

›

The only kids' eBook subscription service that offers thousands of high-quality books from well known publishers like HarperCollins, National Geographic and others.

JavaScript Required

Whoops! We're sorry but Epic doesn't work properly without JavaScript enabled. Check your web browser's settings to make sure it's enabled.