DRRL1

• Hydrometeorological Hazard


  • Atmospheric, hydrological or oceanographic nature
  • Interaction of water and the atmosphere
  • Climate-related phenomena
• Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA)


  Government agency which is tasked to monitor and give forecasts and warnings about atmospheric conditions
• Weather Forecast


  Scientific estimate of future weather condition
• Typhoons, Tropical Cyclones, Hurricanes


  • Intense circular storm
  • Originates over warm tropical oceans
  • Low atmospheric pressure, high winds and heavy rain
• Typhoon


  • Low-pressure area rotating counterclockwise
  • Increased ocean swell, barometric pressure drop, wind speed, and heavier rainfall
• Tropical Cyclones


  Intense low-pressure system which is characterized by strong spiral winds towards the center, called the "Eye" in a counter-clockwise
• Tropical Cyclone Intensity


  • Tropical Depression - maximum winds from 35 kph to 63 kph
  • Tropical Storm - maximum winds from 64 kph to 118 kph
  • Typhoons - maximum winds exceeding 118 kph
• Tropical cyclones in the northern Hemisphere rotate COUNTER CLOCKWISE, those in the Southern Hemisphere rotates CLOCKWISE
• Weather Forecast Creation


  1. Observation

  2. Collection and Transmission of Weather Data

  3. Plotting of Weather Data

  4. Analysis of Weather Maps, Satellite and Radar Imageries and Other Data

  5. Formulation of the Forecast
• Thunderstorm


  • Powerful, short-lived weather disturbance, almost always associated with lightning
  • Produce lightning, heavy rainfall, and high winds, which can cause flooding
• Stages of a Thunderstorm


  1. Cumulus Stage: sun heats the Earth's surface during the day and warms the air around it

  2. Mature Stage: cumulus cloud becomes very large; water becomes large and heavy, and raindrops begin to fall

  3. Dissipating Stage: After 30mins., thunderstorm begins to dissipate; the downdrafts in the cloud begins to dominate over the updraft
• Flood And Flash Flood


  • Water overflows its natural or artificial banks onto normally dry land
  • Receives more water than it can handle
• Types of Floods


  • Inland Flooding: "Ordinary Flooding", inland areas, hundreds of miles from the coast
  • Flash Floods: heavy precipitation in a short period of time 6hrs. Sudden release
  • River Flooding: streams rise and overflow onto surrounding banks
  • Coastal Flooding: low-lying land is submerged by seawater
  • Urban Flooding: lack of drainage
• River Flooding


  Water levels in rivers, lakes, and streams rise and overflow onto the surrounding banks
• Coastal Flooding


  Occurs when dry and low-lying land is submerged (flooded) by seawater
• Inland Flooding


  An ordinary flooding that occurs in inland areas, hundreds of miles from the coast
• Urban Flooding


  When there is a lack of drainage in an city area
• Flash Flood


  Caused by heavy rain or the sudden release of water over a short period of time
• Storm Surge


  • "Daluyong ng Bagyoˮ
  • Irregular sea-level rise during tropical cyclone or "bagyo" occurs
  • Caused by the strong winds and low atmospheric pressures that tropical cyclones produce
• Storm Surge Warning System

  • RED 3 meters above; Take action; CATASTROPHIC
  • ORANGE 1.1-1.3 meter; Alarm; EXPECTED
  • YELLOW 0.5-1 meter; Alert; POSSIBLE
  • GREEN No alert
• El Nino


  • Large-scale ocean-atmosphere climate interaction; "The Little Boy", or "Christ Child" in Spanish
  • Drier and hotter conditions, leading to droughts
• La Nina


  • Below average sea surface temp.; "The Little Girl" in Spanish
  • Wetter and cooler conditions, which can lead to flooding
• Hail Storm


  • Thunderstorm updrafts carry raindrops upward into the atmosphere, where they freeze into ice pellets and fall to the ground
• Tornadoes


  • Produce strong winds, hail, and lightning
• Heat Waves


  • Periods of abnormally high temperatures
• Hurricane & Typhoons


  • Powerful tropical storms that can cause significant damage to infrastructure and human life
  • High winds, heavy rainfall, and storm surges are some of the impacts of hurricanes and typhoons
  • These hazards can result in flooding, landslides, and loss of life
• Robinsons Anemometer

  • Measuring wind speed and direction
• Wind Vane


  • The direction from which the wind is blowing
• Barometer


  • Measure atmospheric pressure, also called "barometric pressure"
• Thermometer


  • Measure the temperature and this is a very important part of weather forecasting
  • Usually, mercury or alcohol