How do fronts & air masses change the weather ?
May 19, 2015
How do fronts & air masses change the weather?
It’s a large body of air which have the same temperature & same
amount of water vapor.
Air masses
Air masses can be formed over:1) Land Dry air mass
2) Water Wet air mass “with lots of moisture”
Types of air masses
Cold & dry Cold & wet Warm & wetWarm & dry
Causes cool weather with no or little precipitation
Causes cool weather with snow.
Causes warm weather with little or no precipitation
Causes precipitation
It is the border between one mass & another.
Fronts
Cold front:- It is formed when a cold air mass pushes
under a warm air mass.- The cold air mass forces the warm air
mass up quickly.- Thick clouds forms as the warm air
rises & cools & rain falls.- Cold fronts often bring stormy
weather.
Types of fronts
Warm front:- It is formed when a warm air mass
pushes a cold air mass.- The warm air mass slides up over the
cold air.- It forms layers of clouds.- Warm fronts often bring steady rain ,
followed by clear warm weather.
Difference between cold & warm fronts
Stationary front:- It is formed when fronts don’t move for
many days.- It causes storms & rain “Flooding” for
many days.- No change in the weather is followed by
stationary front.
Weather map It helps us to know what the weather is like
in an area.{Made from information collected from weather stations}
Symbols on a weather map
Sunny
Sunny & cloudy
Rainy
Red Very hot weather
Orange Warm weather
Yellow Mild weather
Green Cool
Blue Very cold
Colored areas on a weather map
Weather Forecast
Is to predict the weather conditions.
Can you read this weather map?
Severe storms(1) Tornadoes:
-It’s a fast spinning spiral strong wind that stretches From the cloud of the thunderstorm to the ground.
-Tornadoes can have wind speeds greater than 400 km per hour.
-USA has more tornadoes in a year than any other Place.
- They are severe snow storms that can last for hours.
- Blizzards have strong winds, blowing snow & very low air temperature “Cold”
(2) Blizzards:
- They are formed over warm water of oceans, it has a speed of 119 km per hour.
- Hurricanes can last for weeks at the sea.- The wind of the hurricane spins around
the calm center of the storm called: “Eye”- Hurricanes can cause flooding.
(3) Hurricanes:
• There are certain weather safety rules that we should follow in order to be safe from severe weather conditions.
Weather Safety
Watching TV during severe “bad” weather to get directions about what to do.
Examples
Weather sirens are turned on when severe storm is detected.
Flags are used to warm people from a coming hurricane.
Evacuation signs are used to tell people to evacuate “empty” an area when a hurricane is coming.