Weather symbols and depressions

Following on from the last post i thought it would be good to add some information about weather symbols, typical forecasts and how to interpret them to understand weather systems. Additional to this, the post is going to touch upon depressions before leading in to the next post which will discuss The Great British Weather!

So below is an image listing all the relevant weather forecast symbols:

Included in the table above are symbols for fronts which were looked at in the last blog. Additional to this there are symbols for wind, cloud cover and additional conditions such as rain and fog. Although weather forecasts have changed visually over the last 30 years its still important to be able to understand the symbols and be aware of their definition. Below is just an idea of how they would normally be found together:

I have found a blank one of these which could be a quick 5 minute recap at the end of a lesson where students can fill in the blanks about each bit of the diagram

http://ww2010.atmos.uiuc.edu/guides/crclm/act/gifs/wx1.gif

Depressions

Its slightly mismatch to move from weather symbols into depressions but i wanted to add this in before i looked at Great British weather.
So what are they....

Depressions are areas of low atmospheric pressure which create unsettled weather conditions including clouds and rain. This is due to the fact that the air within the depression is rising, causing it to cool and the water vapour within it to condense into clouds. This rising air within a depression causes an area of low pressure at the surface. The deeper the depression the more unsettled the weather. Although conditions like precipitation are common for depressions the conditions are not uniform and can vary through the depression.

The page below has a brilliant explanation of how they form
http://www.bbc.co.uk/schools/gcsebitesize/geography/weather/weathersystemsrev3.shtml

Below is a good activity i have found from the TES website- http://www.tes.co.uk/teaching-resource/Depressions-3009177/

Depressions generally form over the Atlantic and move across to the UK. This weather system is the main influence on the weather experienced in the UK which the next post will be focus on.