Weather hazards

• Global Atmospheric Circulation


  1. Hot air is rising at the equator forming an area of low pressure

  2. Cold air is sinking at the poles forming an area of high pressure
• Coriolis Effect


  Strong winds that create a rotating system of air close to the equator as this is where the earth is rotating faster. This needs to be strong enough to create tropical storms
• Where do Tropical Storms (TS) form?

  • Over warm water (27 degrees)
  • In the summer and autumn
  • 5-15 degrees north and south of equator
  • Coriolis effect needs to be strong enough
• Climate change


  Can affect the distribution, frequency and intensity of Tropical Storms
• Reducing effects of Tropical Storms

  • Prediction: Hurricane watch & hurricane warnings
  • Protection: Reinforcing doors and windows, sea walls & shutters
  • Planning: National hurricane preparedness week in US
• Formation of Tropical Storms

  1. Strong upward movement of air draws up water vapour

  2. Air condenses and forms thunderclouds

  3. Releases heat powering the storm

  4. Several thunderclouds join together and begin to spin (75 miles per hour)

  5. Storm now develops an eye (Calm & cloudless) and eye wall (strongest winds)
• Tropical Storms lose energy when

  • They travel over cooler water and lose the energy supply
  • They hit land they lose the energy supply (warm water) and friction of the land slows them down
• Saffir-Simpson scale


  Used to measure Tropical Storms, Category 1-5 based on wind speed
• UK Weather Roundabout


  • Thunder storms: Increased flash floods
  • Prolonged rainfall: especially during late winter (from Atlantic)
  • Drought & Heat: Rivers can dry up. (heatwave of 2003 killed 20,000 in Europe)
  • Heavy snow & severe colds