4TH MASTERY

• Thunderstorm


  Weather condition that has thunder and lightning, with heavy rainfall and can possibly create a tornado
• Thunderstorm


  • Violent, transient type of weather disturbance associated with the day but happen mostly in the afternoon or evening during summer
• Three Requirements for the Formation of a thunderstorm

  • Moisture (water vapor)
  • An unstable, rapidly rising mass of warm air
  • A strong upward current of air to force moisture to higher, colder levels of the atmosphere
• Thunderstorm Life Cycle


  1. Developing cumulus stage

  2. The Mature Stage

  3. The Final or dissipating Stage
• Lightning


  Abrupt natural, visible high voltage electrical discharge which takes place when positive and negative charges join within the clouds, between clouds or a cloud on the ground
• Thunder


  Acoustic effect of sudden expansion of air caused by the heat released during lightning strike
• Light travels at a rate of 3x10^8 m/s while sound travels only at a rate of 344m/s
• Cloud to ground lightning


  Most dangerous type of lightning
• Infrastructure

  Produces acid rain which can cause deterioration of buildings
• Technology

  Can hit overhead power and telephone cables, satellite dishes, and antennas
• Hail


  Type of solid precipitation
• Hailstone


  Individual piece of layered, rounded or irregularly-shaped ice which occasionally produced during a thunderstorm
• Hailstorm


  Produced by a thunderstorm
• Hail Formation


  1. High amount of moist warm air ascends very quickly into thunderstorm clouds

  2. The water droplets from condensation reach the freezing level so fast
• Factors Favoring Hail


  • Lower temperature
  • Stronger updrafts caused by horizontal winds that tend to be forced upward upon hitting mountains
  • Shorter distance between the clouds and the high grounds which delays melting of hailstone
• Tornado


  Narrow, funnel-or cylindrical-shaped, and intensely rotating columns of wind that form during a powerful thunderstorms and extend from the base of cumulonimbus cloud down to the earth surface
• Tornadoes rotate usually in a counterclockwise direction and reach speeds of up to almost 500 km/h
• Tornadoes can reach more than 1.5 km and can travel for more than 100 km
• Waterspouts


  Basically the same as tornadoes, the only difference is that the rotating column of wind moves over a body of water
• From the year 1990 to 2006 at least 46 tornadoes hit Philippines, resulting in 14 casualties, 72 injured people, 54 missing, 1,364 partially damaged houses, 652 totally damaged houses, and a total of 38,950 people affected nationwide
• According to NOAA, during a tornado, the most important thing to keep in mind to survive or avoid getting hurt is the phrase "Get in, Get down, and Cover Up"
• Flooding


  Abnormal rise of water levels in rivers, coastal areas, plains, and in highly urbanized centers which may be a result of natural phenomena, human activities or both
• Flood can cause


  • Inconvenience for travelers
  • Damage to properties
  • Loss of lives
• Primary Flood types and Cause

  • Riverine - level of water flowing through rivers increasing and goes beyond the average water level - caused by extreme and sustained rainfall
  • Estuarine and Coastal - occur when seawater encroaches low lying land that is usually still above sea level - can be a result of storm surge
• Storm Surge


  Localized unusual increase of sea water level beyond the predicted astronomical tide level due to intense winds and lowered atmospheric pressure during the passage of an intense tropical cyclone from the sea to the land
• Causes of Unusual High Tides

  • Astronomical High Tides - short term sea level rise caused by the gravitational pull of the moon
  • Spring Tides - happen when the sun, earth, and moon aligned during new moon and full moon, causing water to bulge in the direction of the alignment
• Urban Flooding


  Usually occur in highly populated, developed areas set on relatively low lying areas, due to lack of proper drainage systems
• Causes of Urban Flooding

  • Obstruction of waterways by solid waste
  • Obstruction of waterways by industrial waste
  • Wrong locations of settlements
• Catastrophic Flooding


  Result from ground failure or major infrastructure failure
• Causes of ground failure

  • Weakening of the rock or soil
  • Liquefaction
  • Occurrence of landslide
• Causes of infrastructure failure

  • Miscalculation of engineering design
  • Thunderstorms
• Flash Floods


  Rapid, short-lived, and violent arrival of a large volume of water which can be caused by intense localize rainfall on land that is saturated or unstable to absorb water
• Fire Tetrahedron


  A visual aid that reminds us of the four important ingredients to initiate and sustain fire: Heat, Fuel, Oxidizing agent

  
• Pyrolysis


  Chemical decomposition of solid fuels which produces gas fuel through application of heat
• Types of wildfires

  • Ground fires
  • Surface Fires
  • Crown Fires
  • Ladder Fuels
• Causes of Wild Fire

  • Natural - triggered by lightning strikes during thunderstorms or lava flows during volcanic eruptions
  • Human Activities - kaingin and charcoal production, accidental fire from lighted cigarettes or improper extinguished bonfires in campsites within the forest
• Choosing Fire Extinguishers


  • Water foam
  • Carbon dioxide
  • Dry Chemicals
  • Wet chemical
  • Clean Agent
  • Dry Powder
  • Water Mist
• El Nino


  Prolonged unusual warming of sea surface temperature in the central pacific
• The occurrence of El Nino has been cause of severe dry spells or drought in the Philippines, resulting in significant damage to agriculture
• La Nina


  Prolonged unusual cooling of sea surface temperatures in central and eastern equatorial Pacific that may last for 3 years