Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
Define depression
|
Area of low pressure which usually bring rain, cloud and wind
|
|
|
When do depressions occur
|
They occur when warm air meets cold air
|
|
|
How long does it take an average depression to pass over the British Isles
|
Between 1 and 3 days
|
|
|
What is a front
|
The point at which cold air meets warm air
|
|
|
How many fronts are there in a typical depression
|
Two;
the warm front being forced to rise over the cold air & the cold front which follows undercuting the warm air in front of it. |
|
|
What is the weather like along a front
|
Usually cloud and rain
|
|
|
What direction do strong winds blow in - clockwise or anti-clockwise
|
Anti clockwise
|
|
|
Why is there usually cloud and rainfall along a front
|
This occurs because the warm air cools and condenses when it meets the cold air.
|
|
|
Why do air masses have different densitites
|
Because they have different temperatures
|
|
|
Is warm air more or less dense than cold air
|
Warm air is less dense
|
|
|
What is the first sign of an approaching warm front
|
The formation of high thin clouds (cirrus)
|
|
|
As warm air rises does the atmospheric pressure fall or rise
|
Rapid fall
|
|
|
As cold air replaces warm air what happens to the temperature and atmospheric pressure
|
Temperature falls;
Atmospheric pressure rises |
