Chapter 3 – page 39Chapter 3 – page 39

READING A WEATHER MAPREADING A WEATHER MAP

TODAY’S OBJECTIVES

• LOOK AT A COUPLE OF WEATHER MAPS1. From your textbook from chapter 3, page 392. Another from the NOAA website

• DEFINE SOME TERMS• MAKE WEATHER PREDICTIONS

1. With the maps2. With our senses

• TAKE A SHORT QUIZ• HOMEWORK

SURFACE MAP

SURFACE CHART SYMBOLS

• LOW PRESSURE AREA

• HIGH PRESSURE AREA

• WARM FRONT

• COLD FRONT

• STATIONARY FRONT

• WIND DIRECTION

SURFACE MAP

CURRENT FEATURES

@ www.weather.com

WORDS TO KNOW• Meteorology –--------

• Low Pressure---------

• High Pressure---------

• Front------------------- • Warm Front-----------

• Cold Front-------------

• Wind Direction--------

• Humid-----------------

The study of weather and climate

Winds that blow inward and counter-clockwise

Winds that blow outward and clockwise

The boundary between two air masses of different densities that move from west to east

Warm mass of air- slower and lower density

Cold mass of air- faster and higher density

Always labeled by the direction from which they blow

Air with lots of water vapor

NOW SOME AMATEURFORECASTING

• 1ST – CLOUD FORECASTING

• 2ND – WIND FORECASTING

• 3RD- SENSES FORECASTING

Cirrus Cloud

The first kind of cloud is a cirrus cloud. Cirrus clouds are thin and wispy, and are found very high in the sky. Cirrus clouds point in the direction the wind is blowing. No precipitation falls from cirrus clouds. They are a sign of fair weather for now and the very near future.

Altocumulus Clouds

Next are the altocumulus clouds. These clouds are like fuzzy bubbles in long rows or strings. If you see altocumulus clouds, it usually means that a cold front is coming. If it's summertime and warm and humid, altocumulus clouds may turn into thunderstorms when the cold front approaches.

Nimbostratus Clouds

After that are the nimbostratus clouds. These clouds are dark and low-hanging clouds that cover the whole sky. They bring with them light to moderate precipitation.

Cumulus Clouds

Then there are fair weather cumulus clouds. These clouds look like big cotton balls in the sky. They have very large spaces of clear sky in between them. Normally they don't carry any rain, but during the spring and summer they can change into cumulonimbus clouds.

Cumulonimbus

Cu-mu-lo-nimbus clouds are thunderstorm clouds. They are tall and wide clouds that have heavy rain, thunder and lightning. If you see these clouds on the horizon, it is likely it will rain very soon.

The Funnel Cloud

THE TEST• PART ONE – YOUR DAD• Hope you remember your lesson about

cloud forecasting, because now you’re going to need it! Your dad wants to spend the afternoon resting in his hammock. He wants to know if it will rain this afternoon, or if it will be clear.

• So you look at the sky and see if there are any clouds floating above you. You see long strings of clouds that stretch across the sky. The spring day is warm but not humid.

• What do you tell your dad?

PART ONE - YOUR DAD

• If you told your dad it was going to rain, he spent the day sleeping in the tent. He woke up hot and sweaty calling your name.

• If you told your dad that it was going to be a nice and warm afternoon, you were right! Good job! The clouds you saw were altocumulus. They are a sure sign that a cold front is coming, and a cold front can sometimes cause rain. But remember that is was warm but not humid. That means that there wasn’t enough moisture in the air for it to rain. So the afternoon may have gotten a little cooler, but should have stayed nice and sunny.

WIND FORECASTING

WIND FORECASTING• Forecasting the wind is simple, but it only works if the wind is strong enough to feel

it. Early in the morning, the wind can tell you how warm a day will be.

• 1st– Know which direction is north – use a compass!• 2nd– Face that direction – the direction behind you will be what? To your left is

west and to your right is east.• 3rd– Then feel which way the wind is coming from – wet your finger if you have too!• 4th– A south wind usually means that warmer weather is on the way soon. A north wind usually means that cooler and drier weather is on the way. East or west winds can mean a variety of things, which makes it difficult to forecast.• 5th– If there’s a large body of water to your south, then this rule won’t work. Wind that travels across a body of water will feel cooler in the summer and warmer in the winter.• 6th– Hope you remember your wind forecasting tricks!

THE TEST• PART TWO – YOUR MOM

• Hope you remember your lesson about wind forecasting, because now you’re going to need it! This morning your mother wants to collect pine cones for her collection. It’s a cold morning, and she wants to know if it will get any warmer while she’s picking pine cones.

• So you find a clearing where you can stand still and feel the wind. You find what direction is north, and notice that there is large lake to your south. You feel a strong wind coming from the north.

• Based on the wind, what do you tell your mom?

PART TWO – YOUR MOM

• If you told your mom that the weather would get warmer while she’s out hiking, boy are you trouble. She went out wearing a tank-top and shorts. When she returned to the camp site, she was very cold because the weather didn’t get any warmer. She also walked through poison ivy and got it all over her bare legs.

• If you told your mom that the weather would stay cold while

she was out gathering pine cones, you were right! Good job! When you made your forecast, you were facing the north. The wind was hitting you in the face, so the wind was coming from the north. This typically means that the weather will be cool and dry. If the wind was coming from the south, you shouldn’t trust it. Wind that crosses a body of water takes or loses heat from the water, and won’t be the real temperature of the air. You should find another place to check the wind or check the clouds as well.

SENSES FORECASTING

• SIGHT-is the easiest to use when you forecast. You use your sight when you watch clouds to forecast the weather.

• TOUCH-is another easy one. Like when your face gets cooler on a hot day when a cloud passes over. You also use touch to feel the wind direction.

• HEARING-is useful for hearing an approaching storm. You can hear the wind blowing through the trees.

• SMELL-can help you predict the weather. Rain and snow have a distinct smell.

• TASTE-You really can’t predict the weather with this sense. If you insist on trying it, don’t eat the yellow snow.

THE TEST• PART THREE– YOUR BROTHER• Hope you remember your lesson about senses

forecasting, because now you’re going to need it! Your brother wants to go canoeing this afternoon, and wants to know if it’s going to rain this afternoon. He wants you to use your senses forecasting lesson to see if the weather will stay nice this afternoon. And if you don’t get it right, he’s going to make you use your sense of taste to eat dirt.

• So you use your senses forecasting lessons to see what the weather will be. With you sight, you see dark clouds that are covering the sky in the distance. With your sense of touch, you feel a warm wind coming from the south. With your sense of hearing, you hear a dull rumbling off in the distance.

• So what do you tell your brother?

PART THREE YOUR BROTHER

• If you told your brother he could go canoeing,… bon appetite’.

• If you told your brother that it is likely to rain, you were right! Good job! Your brother decided not to go canoeing and played cards with you instead. When it started raining you moved your card game inside.

• There were many signs it was going to rain. Your sense of sight caught the nimbostratus clouds, clouds that usually bring rain. Your sense of hearing let you hear thunder from the storm in the distance. If your sense of smell was keen you would have been able to smell the rain, too.

THE QUIZ• Where are cirrus clouds usually found?

– In a thunderstorm– Very high in the sky– Close to the ground

• Altocumulus clouds often come before what?– A cold front– A warm front– A bus

• What kind of precipitation is a nimbostratus cloud associated with?– Hail– Heavy thunderstorms– Light to moderate precipitation

• What kind of clouds look like big cotton balls?– Cirrus clouds– Fair weather cumulus clouds– Dense fog

• What direction does warm weather usually come from in the Northern • Hemisphere?

– North– West– South

• Which of your five senses doesn’t help you forecast?– Sight – Touch – Taste

THE QUIZ CONT’D• What is a weather front?

– It is a mirage– When two air masses overlap– The boundary between two air masses

• What is meteorology?– The study of meteors– The study of weather and climate– It is a rocket science

• What is a low pressure center?– Winds that blow inward and counterclockwise– Winds that blow outward and counterclockwise– Winds that blow inward and clockwise

• What is a cold front?– A cold mass of air that is slower and higher than a warm front– A cold mass of air that is faster and lower than a warm front– A cold mass of air that is faster and higher than a warm front

• What’s another name for a thunderstorm cloud?– Cirrus cloud– Chuck– Cumulonimbus

• What can a large body of water do to the air during the summer?– Increase the air temperature– Decrease the air temperature– Create a snow storm

HOMEWORK• After school today, make a weather

prediction for tomorrow’s weather, using what you have learned today. How did you make your prediction?

• Then later listen to or watch a weather forecast on radio or TV.

• Compare the two predictions.• Did you agree or disagree?