1. Depressions  I just cannot carry on !  Or the wet and windy ones

2. Characteristics of a depression  On the white board you need to list as many characteristics of a depression that you can think of …  Go on take a chance !

3. Characteristics of a depression  Rain ….  And more rain  Strong winds  Low pressure – usually below 1000mbs  Closed isobars that are close together on a weather map  Isobars are close together giving steep pressure gradients

5. How do depressions form ?  Two air masses meet along the POLAR FRONT  Polar Maritime Air from the North Atlantic which is cold dense and moist meets  Tropical Maritime Air from the SW which is warm, less dense and also moist.  The mixing of these creates the depression.

6. This is what a depression can look like approaching the UK

7. Formation of depressions Initially make notes on  Introduction  Warm Front  Cold Front  Occluded Front or Occlusion  Trough Cut & paste their diagrams into your word “notes” – use the link below.  Met Office: Weather systems Met Office: Weather systems

8. Formation of depressions  Use the link at the end of this slide  now explain how a depression forms and dies (the four stages)  – you could cut & paste some of the diagrams/tables but put the writing into your own words - make sure you read & understand them !  Met Office: Weather systems Met Office: Weather systems

9. Typical weather sequence of a depression  You must be able to describe (and explain) the sequence of weather as the warm front approaches, passes, you enter the warm sector and then the cold front passes.  The table is on the website is very useful !  Take note of the weather maps – you must be able to recognise a depression from these. Link is below.  Met Office: Weather systems Met Office: Weather systems

10. Other places to look on the website  Read through the link below – take note of the fronts & what the various weather maps show – in an exam you will probably only get a b/w copy !  Met Office: Weather charts Met Office: Weather charts

11. Depressions – check list  Make sure that you have notes and/or diagrams which show  The characteristics of a depression  How they form (and die !)  The sequence of weather as they pass  What they look like on a weather map/satellite photo  Can you explain as well as describe ?

12. Location of Presentation Make a note of this ! You need to use this presentation for your next few lessons It is at Depts. on Upper (U) > students > upper depts > Geography > depressions. Keep it safe !!! Further links – look at the diagrams and make further notes from S-cool.co.uk A level & AS revision > Geography > Weather Conditions