Download It`s Just a Front

It's Just a Front
By Patti Hutchison
The weather forecaster says a cold front is coming
your way. How cold will it be? Will it rain or snow? How
long will it last? What is a front?
1
Giant air masses are constantly forming over the
earth. These air masses can be warm and wet or dry and
cold. They are always on the move. When two different air
masses crash into each other, a front is formed. There are
four different kinds of fronts: cold fronts, warm fronts,
stationary fronts, and occluded fronts. Fronts can stretch for miles or affect
only a section of the country. But they always bring changes in the weather.
2
A cold front contains cold, dense air. When it bumps into a warmer air
mass, it forces the warm air up along a steep front. The warm air rises and
cools. It condenses and forms clouds. You can feel the air getting cooler. Rain
or snow showers occur ahead of the front. Sometimes there are
thunderstorms. In fact, cold fronts can cause violent weather such as
tornadoes. The precipitation usually lasts only a little while. A blue line with
triangles shows a cold front on the weather map. The triangles point in the
direction the front is headed.
3
When you see a red line with half circles on the map, it shows a warm
front. A warm front is formed when a large mass of warm air collides with
colder air. The warm air takes over. There will be a lot of thick clouds and rain
behind the front, but the temperature will be warmer. It will be very windy. The
rain may last one to two days.
4
A stationary front happens when two air masses meet and neither one
takes over. The temperature and pressure are almost the same in both air
masses. They stall out. Sometimes there are some clouds and a little bit of
precipitation. This usually happens behind the edge of the front. On a weather
chart a stationary front looks like a combination of a warm front and a cold
front. It is a blue line with blue triangles on one side and red half circles on the
other.
5
A purple line with triangles and half circles on the same side shows an
occluded front. This happens when a large, cold air mass moves in fast and
overtakes a warm front. The warm air is squeezed upward between the cold
air masses. Precipitation will happen on both sides of the front.
6
Weather fronts are shown on the map in several different ways. No matter
what kind of front is passing over your area, you can count on some kind of
precipitation. It may last a few hours or a few days. The air behind it will be
much different from the air ahead of it.
7
Copyright © 2017 edHelper
Name _____________________________
Date ___________________
It's Just a Front
1. A front forms when ______.
2. On a weather map, a red line with half
circles shows a(n) ______.
Two air masses bump into each
other
Warm front
Two air masses move away from
Occluded front
each other
Cold front
Two storms combine
3. The blue triangles of a cold front point
in the direction ______.
The front is going
Where the temperature is colder
The front has come from
4. Which type of front usually causes the
most violent weather?
Cold front
Stationary front
Warm front
5. Where does rain happen in an
occluded front?
6. Explain what a stationary front looks
like on a weather chart.
Name _____________________________
Date ___________________
It's Just a Front
Explain the difference between a stationary front and an occluded front.
Name _____________________________
Date ___________________
It's Just a Front
Why do you think a stationary front is shown as a blue line with blue triangles on
one side and red half circles on the other side?
It's Just a Front
By Patti Hutchison
section
direction
country
between
last
upward
ahead
chart
dense
area
cools
weather
giant
earth
cooler
showers
lasts
Directions: Fill in each blank with the word that best completes the reading
comprehension.
The weather forecaster says a cold front is coming your way.
How cold will it be? Will it rain or snow? How long will
it (1) _______________________ ? What is a front?
(2) _______________________ air masses are constantly
forming over the (3) _______________________ . These air
masses can be warm and wet or dry and cold. They are always
on the move. When two different air masses crash into each
other, a front is formed. There are four different kinds of fronts:
cold fronts, warm fronts, stationary fronts, and occluded fronts. Fronts can stretch for
miles or affect only a (4) _______________________ of
the (5) _______________________ . But they always bring changes in
the (6) _______________________ .
A cold front contains cold, (7) _______________________ air. When it bumps
into a warmer air mass, it forces the warm air up along a steep front. The warm air
rises and (8) _______________________ . It condenses and forms clouds. You can
feel the air getting (9) _______________________ . Rain or
snow (10) _______________________ occur (11) _______________________ of
the front. Sometimes there are thunderstorms. In fact, cold fronts can cause violent
weather such as tornadoes. The precipitation
usually (12) _______________________ only a little while. A blue line with
triangles shows a cold front on the weather map. The triangles point in
the (13) _______________________ the front is headed.
When you see a red line with half circles on the map, it shows a warm front. A
warm front is formed when a large mass of warm air collides with colder air. The
warm air takes over. There will be a lot of thick clouds and rain behind the front, but
the temperature will be warmer. It will be very windy. The rain may last one to two
days.
A stationary front happens when two air masses meet and neither one takes over.
The temperature and pressure are almost the same in both air masses. They stall out.
Sometimes there are some clouds and a little bit of precipitation. This usually happens
behind the edge of the front. On a weather (14) _______________________ a
stationary front looks like a combination of a warm front and a cold front. It is a blue
line with blue triangles on one side and red half circles on the other.
A purple line with triangles and half circles on the same side shows an occluded
front. This happens when a large, cold air mass moves in fast and overtakes a warm
front. The warm air is
squeezed (15) _______________________ (16) _______________________ the
cold air masses. Precipitation will happen on both sides of the front.
Weather fronts are shown on the map in several different ways. No matter what
kind of front is passing over your (17) _______________________ , you can count
on some kind of precipitation. It may last a few hours or a few days. The air behind it
will be much different from the air ahead of it.