Lesson 1 -🌦️Hydrometeorological Hazards

• Weather


  Conditions of the atmosphere over a short period of time
• Climate


  How the atmosphere behaves over a long period of time and space
• Elements of Weather


  • Temperature
  • Atmospheric pressure
  • Wind
  • Humidity
  • Clouds
  • Amount of rainfall
• Tropical Cyclones


  A severe weather disturbance characterized by strong winds and heavy rains which revolve around a central low pressure area
• 20 tropical cyclones enter the Philippine Area of Responsibility (PAR) annually
• Anatomy of Tropical Cyclones
• Thunderstorm


  A weather condition that produces lightning and thunder, heavy rainfall from cumulonimbus clouds and possibly a tornado
• Signs of an Impending Thunderstorm


  • Towering of cumulonimbus clouds
  • Darkening skies
  • Flashes of lightning and gusty winds
  • Sound of thunder
  • Static on your communication equipments
• Flooding


  The inundation of land areas which are not normally covered by water
• Causes of flood

  • Cutting of trees and urbanization of large areas
  • Prolonged rainfall over several days
  • Intense rainfall over a short period of time
  • Debris jam causes a river or stream to overflow
• Flood warning

  • Yellow warning (7.5-15 mm heavy rain, flooding is possible, monitor the weather condition)
  • Green warning (15-30mm intense rain, flooding is threatening, alert for possible evacuation)
  • Red warning (more than 30mm rain, serious flooding expected in low lying areas, evacuation)
• Storm Surge


  A rise of seawater above normal sea level on the coast, generated by the action of weather elements such as cyclonic wind and atmospheric pressure
• Color-coded warning system


  • Not provided
• Tornado


  A violently rotating column of air extending from a thunderstorm to the ground
• Signs of an impending tornado


  • The appearance of funnel-shaped column from the base of cumulonimbus clouds
  • Feels warm, humid, uncomfortable calm weather
  • Lightning and thunder
  • Roaring and buzzing sound of the tornado as it reaches the ground
• Safety tips during tornado


  • Go to windowless, interior room
  • Get in basement if at possible
  • Protect head and neck
  • If caught outside, get in ditch or drainage area
  • Be very aware of flying debris
• Other weather phenomena

  • El Nino
  • La Nina
  • Monsoons
• WEATHER


  Conditions of the atmosphere over a short period of time
• CLIMATE


  How the atmosphere behaves over a long period of time and space
• CLIMATE


  Average regional weather pattern over decades
• WEATHER

  Can change within minutes or hours
• anatomy of a tropical cyclone

  eye

  eyewall

  Inner rain bands

  outer feeder bands
• elements of the weather

  • refers to how hot or cold the atmosphere

  temperature
• elements of the weather

  • weight of the atmosphere overhead.

  atmospheric pressure
• elements of the weather

  • forms because of differences in temperature and atmospheric pressure between nearby regions.

  wind
• elements of the weather

  • refers to the amount of water vapor in the air.

  humidity
• elements of the weather

  • can affect the amount of sunlight reaching the Earth’s surface.

  clouds