they get using
shows the weather over a part of
help meteorologists forecast the
show what the weather is like at a
certain time, such as right now.
help scientists make predictions about what
the weather will be in the future. A prediction
is a guess about what will happen in the future.
show temperature and precipitation
may also show other types of weather data.
will show a list of symbols called a key. The key
tells you what the different symbols mean.
Weather maps show the
movement of air masses
An air mass is a large body of air
with the same temperature and
Humidity is the amount of water
vapor in the air.
Humid air contains a lot of water
An air mass can cover thousands
of square kilometers.
There are four basic types of
1.Cold and dry
2.cold and humid
3.warm and dry
4.warm and humid.
Weather maps also show fronts.
A front is a place where two different air masses meet.
Triangles show a cold front.
Half circles show a warm front.
The triangles and half circles point in the direction the front
a cold air mass bumps up against a warm
Strong storms happen at cold fronts.
Thunderstorms are likely in warm
In winter, snowstorms are likely.
When a cold front passes over an area,
the temperature drops .
warm air mass meets a colder air mass
and slowly rides up over it.
Sheets of gray clouds form at warm
fronts and often bring rain.
After a warm front passes over an area,
the temperature rises.
forms when two air masses meet and stop moving.
Clouds and precipitation form at a stationary front.
Weather maps also show air pressure.
When you look at weather maps, you will also see circles with H’s or
L’s inside them.
The H stands for “high”. A high is an area of high air pressure. Highpressure areas usually bring fair weather
The L stands for “low”. A low is an area of low-pressure. Lowpressure areas usually bring storms.
Recording the Weather
• Data used to make weather maps come from local
weather stations all over the world.
A weather station is a place where weather data are
You can use simple weather tools to gather
temperature, precipitation, and other data about the
weather where you live.
Then you can record the data in a table like the one
below, or on a graph.
Why are weather
1.What does a key on a weather map
a.What symbols on the map mean
b.What today’s temperature is
c.Where mountains are located
d.How to predict the weather
2.What does the letter H on a weather
a.An area of high pressure
b.A high front
c.An area of high mountains
d.An area of high temperatures
3. Look at this weather map symbol. What does
the symbol stand for?
c.Warn, dry air mass
4. What is a front?
a.A place where air masses meet
b.The front part of a storm
c.An area of very high wind
d.An area that has fair weather.