Tropical storms

• Tropical Storms


  Hurricanes, cyclones, typhoons
• Tropical Storms


  • Rapidly rotating storm system
  • Low pressure centre
  • Closed low-level atmospheric circulation
  • Strong winds
  • Spiral arrangement of thunderstorms that produce rain
  • Well-defined eye (clear of cloud)
• Tropical storms develop as a result of particular physical conditions
• Tropical storms happen in the tropics because the oceans are hot, they don't happen further up because it's too cold
• The global distribution of tropical storms are located in the tropics (between Tropic of Cancer and Capricorn)
• There are hurricanes in Central America, cyclones in East Africa and West Australia, and typhoons in Asia
• Tropical storms are usually on the coast of countries, not in the countries
• The most intense storms are found in the Pacific ocean
• The tropical storms move further north in the Atlantic ocean
• Conditions needed for tropical storms to develop

  • Hot (summer warmed) oceans in the tropics
  • Coriolis Effect (5-15° N/S) needed
  • Hurricanes can die over land
• Formation and development of tropical storms

  1. Warm air rises from ocean surface

  2. Coriolis force causes the storm to rotate

  3. Thunderstorms merge into a core of low pressure

  4. Storm picks up moisture and increases in speed as it moves across the ocean

  5. Storm weakens when it moves over land and loses its fuel source (warm water)
• The wall of the eye has the strongest winds (120-200mph)
• The central eye is cloud free (descending air)
• Tropical storms can lose energy over cold oceans
• Prevailing trade winds push the cyclone westwards, driving a storm surge ahead of it
• As the water vapour rises

  It cools and condenses, transferring energy into the atmosphere, leading to thunderstorms
• As the storm rotates


  The winds pick up, and the rate of evaporation increases even more, transferring even more energy into the atmosphere
• Tropical cyclones form over deep (60m) warm (27°C) oceans found between the tropics
• The tropical storm becomes a hurricane when the wind speeds reach 75mph
• Climate change is making the oceans warmer


  • Increases the size of tropical oceans
  • Increases the areas where tropical storms can form
• Warmer oceans


  Increase in tropical storms
• Warmer oceans

  More energy for tropical storms, increasing their intensity
• Dolnily is Are sity of Tacloban particularly acks Podca
• Dolnily

  • Located on the eastern side of island - near to Pacific which is where typhoons come from
  • Exposed Bay with a funnel shape
  • Lots of people live there for trade/fishing
  • No airport nearby for evacuation or aid
  • Low lying land flood risk from rain storm
• Typhoon Haiyan

  • Responses
• Responses to Typhoon Haiyan

  1. Immediate

  2. Before the Storm

  3. Long-Term Rebuilding
• When Typhoon Haiyan hit no one paniced (they are used to it)
• People moved to basements to escape the winds
• International aid was good but helicopters were small-need a lot of trips
• Aid agencies like Save the Children arrived quick
• 2/3 of fisherman still didn't have boats 18yrs later-90% recovered
• Primary Effects of Tropical Storms

  • Buildings and bridges destroyed
  • Rivers and coastal areas flood due to heavy rain and storm surge
  • People drown, or they're injured of killed by debris that's blown around
  • Roads, railways, ports and airports are damaged
  • Electricity cables are damaged, cutting off supplies
  • Sewage overflows due to flooding. The sewage contaminates water supplies
• Secondary Effects of Tropical Storms

  • People are left homeless, which can cause distress, poverty and ill health or death due to lack of shelter
  • There's a shortage of clean water and a lack of proper sanitation-this makes it easier for disease to spread
  • Roads are blocked or destroyed so aid and emergency vehicles can't get through
  • Businesses are damaged or destroyed causing unemployment
  • There can be shortage of food if crops are damaged, livestock are killed, or supply lines are blocked
• Immediate Responses to Tropical Storms

  1. Evacuate people before the storm arrives

  2. Rescue people who have been cut off by flooding and treat injured people

  3. Set up temporary shelters for people whose homes have been flooded or damaged

  4. Provide temporary supplies of water, food, electricity, gas and communications systems

  5. Recover any dead bodies to prevent the spread of disease

  6. Foreign governments or NGOs may send aid workers, supplies, equipment, or financial donations to the area

  7. Tech companies may set up disaster response tools, allowing damage to be recorded, people to confirm their safety, and alerts about areas at risk from the storm to be shared
• Long-Term Responses to Tropical Storms

  1. Repair homes of re-house people who have been displaced due to damaged buildings

  2. Repair or replace damaged infrastructure

  3. Repair and improve flood defence systems, eg. levees and flood gates

  4. Improve forecasting techniques to give people more warning in the future

  5. Provide aid, grants, loans or subsidies to residents to repair and strengthen homes

  6. Promote economic recovery in the area and encourage people to return to the areas

  7. Improve building regulations so that more buildings withstand hurricanes or change planning rules so homes can't be built in the most risky areas
• The predicted path of the storm was further to the north
• People weren't properly warned about the risks of storm surges
• The funnel shaped bays directly the storm surge towards settlements
• Not enough people were evacuated from low lying coastal areas
• The storm surge was much higher than had been the case in past storms