typhoons

• Typhoon (Cyclone)


  Windstorm - storm with high winds but little to no rain
• Gust front


  Leading edge of cool air rushing down and out from thunderstorm
• Windstorm


  • Wind speeds typically exceed 55 kph
• Hurricane


  Tropical cyclone in atlantic and eastern pacific ocean
• Northern hemisphere moves counterclockwise while in southern hemisphere it moves clockwise
• How tropical cyclones form

  1. Warm ocean temperature (28ºc) needed

  2. Heat is drawn from oceans creating heat engine

  3. Tall tower of clouds are formed within storm as warm ocean evaporates

  4. Air cools as it rises and releases latent heat which causes more clouds to form
• Wind intensity scale


  • Category 1 - minimal damage (119-153 kph)
  • Category 2 - moderate damage (154-177 kph)
  • Category 3 - extensive damage (176-208 kph)
  • Category 4 - extreme damage (209-251 kph)
  • Category 5 - catastrophic (252+ kph)
• Potential damage due to wind

  • Structural damage
  • Collapse of structural elements/building along with damage to building envelope
  • Water infiltration into exterior building wall
  • Leakage between door and frame, frame and wall, and thresh
• Factors contributing to wind damage

  • Low quality construction
  • Inappropriate techniques and utilization of low resistance materials
  • Failure of doors and windows due to wind pressure
  • Excessive openings in building envelope
  • Location of building
  • General roughness of surrounding terrain
  • Height of building above ground
  • Height of building more than surrounding structures/vegetation
  • Configuration of building
  • Surrounding topography
• 1. 10 storms strike the philippines each year
• Typhoon milenyo (2006) - strongest typhoon to hit in metro manila
• Typhoon yolanda - wind speed reaching 315 kph
• Risk reduction strategies


  • Prepare evacuation plans and warning systems
  • Construct wind resistant/easily rebuildable houses
  • Secure elements that can blow away and cause damage
  • Protective measures for possessions at risk
  • Protect food storage facilities
  • Well informed public regarding hazard
  • Effective warning system
  • Make structures that can withstand wind forces
  • Introduce agricultural practices and crops that can withstand high winds
• Thunderstorm


  Storm with lightning and thunder
• How thunderstorms form


  Rapid upward movement of warm, moist air
• Lightning


  Massive electrostatic discharge between electrically charged regions within clouds
• Types of lightning


  • IC - cloud to itself
  • CC - cloud to another cloud
  • CG - cloud ground
• Damage thunderstorms can do

  • Lightning causes fires
  • Rainstorms can cause flash flooding
  • Hail up to size of softballs damages cars
  • Strong winds knock down stuff
• Types of weather maps

  • Weather map
  • Satellite map
  • Radar map