DRRR 4TH MASTERY

• Thunderstorm


  • Different from a storm
  • Characterized by a weather condition that has thunder and lightning
  • Has heavy rainfall and can possibly create a tornado
  • A 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) which must be readily available in the lower atmosphere to produce clouds and precipitation during storm formation
  • 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. Mature Stage

  3. Final or dissipating Stage
• Development of a Storm

  • Ordinary rainfall
  • Tornado
  • Hailstorms/ snow
• Storms are more dangerous than earthquakes


  Only if it forms a tornado
• Tornado


  • Has no warning or no foreshocks
  • Happens mostly in the afternoon or evening during summer because morning's temperature is colder than the afternoon
• Thunderstorm life

  • Cumulus cloud
  • Cumulonimbus cloud
  • Stratuscumulus cloud - ''thunderclouds'' that can possibly be a thunderstorm
• Lightning


  • The 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
  • It gives off a flash that last a few tenths of a second and is always followed by thunder
• Thunder


  • The 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


  The most dangerous type of lightning
• Effects of Lightning Strike to Human

  • Lightning strike could directly cause harm to people through contact between the main lightning channel or its branches and the person's body or a conductor the person is touching
  • Lightning strike could also directly cause either blunt force trauma to a person thrown by a shock wave or hearing damage due to thunder or electrical interferences to gadgets they are using like, phones, headphones, and hearing aids
  • Lightning strike may also cause injuries or casualties through secondary effects like explosions and fire
• Lightning Safety Rules

  • The most important thing to keep in mind during a thunderstorm is to stay indoors
  • In school during thunderstorms, do not leave the classroom or in school building until it has fully ended
  • It is usually safe to go outdoors only after at least 30 minutes upon hearing the last thunder roar
• Danger Indoors


  • Avoid staying nearby and watching the lightning through windows or glass portion of doors
  • Avoid contact with any that could conduct electricity like: Appliances, Light switches and electric sockets, Faucet, pipes and shower head, Steel banisters, Mobile phones or telephone
• Danger Outdoors


  • Avoid open vehicles and small unenclosed structures like waiting sheds and wooden huts
  • Do not touch any electrical wires or wiring systems and plumbing that provides mechanism for electric charge
  • Using an umbrella can only attract lightning if it makes you stand out as the tallest feature in a certain area
  • If you witness someone get struck by lightning, do not hesitate to provide assistance
  • If you are driving or travelling with others by car, find a safe place to pull over somewhere
• Effects of lightning on infrastructure and technology

  • Infrastructure- when lightning strikes it produces acid rain which can cause deterioration of buildings
  • Technology- overhead power and telephone cables, satellite dishes, and antennas may be hit by lightning strikes
• Other Tips

  • Be aware of metals (conductor of electricity) - lightning charges travel through it
  • Wet body
  • Don't use your devices
• Tornadoes


  • 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
  • Rotates usually in a counterclockwise direction and reach speeds of up to almost 500 km/h
  • Can reach more than 1.5 km and can travel for more than 100 km
  • Is also known as twisters and erroneously, as cyclones
  • Locally these are called buhawi or ipo-ipo
  • Can cause damage and claim lives in communities in a matter of seconds
  • Can form very quickly that issuing warnings may be impossible
• Waterspouts


  • Basically the same as tornadoes, the only difference is that the rotating column of wind moves over a body of water
  • Formations are spawned by thunderstorms
• From the year 1990 t0 2006 at least 46 tornadoes hit Philippines

  Records from NDRRMC claim that these tornadoes resulted 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
• Safety Tips during a tornado

  • Get in - Seek shelter in a sturdy house or building, go into the innermost portion of the structure
  • Get down - Go to the lowest level of the structure, if there is a basement, this would be a good place to hide
  • Cover up - Protect yourself from debris that may possibly fail or fly by and hit you
• Hail


  A type of solid precipitation
• Hailstone


  The 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 (an effect called orographic lifting)
  • Shorter distance between the clouds and the high grounds which delays melting of hailstone
• Hazards Due to Hailstorms

  • Can create dents or abrasions on the coating of automobiles and metal roofs which may initiate corrosion and eventually leaks
  • Can result cracking or breakage of glass in automobiles or lightweight materials used in skylight roof of houses
  • Can cause hazards to aircraft operation
• Flood and Storm Surge


  The 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
• Types of Flooding


  • Riverine - when the level of water flowing through rivers increases and goes beyond the average water level
  • Estuarine and Coastal - flooding occur when seawater encroaches low lying land that is usually still above sea level; flooding in these area can be a result of storm surges
• Storm Surge


  A 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 - is a 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
• Urban Flooding


  • Usually occur in highly populated, developed areas set on relatively low lying areas
  • Caused by: Saturation of the ground due to too much rainfall, The presence of large areas of impermeable surfaces like concrete pavements and rooftops
• Causes of Urban Flooding

  • Lack of proper drainage systems - A proper drainage system has: Wide coverage, Sufficient capacity to accommodate volumes of water based on predicted worst case flooding event scenario, Not prone to blockage
  • Obstruction of waterways by: Solid, 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, and occurrence of landslide
• Causes of infrastructure failure


  • Miscalculation of engineering design and thunderstorms
• Flash Floods

  A rapid, short
• When a high tide coincides with the occurrence of a tropical cyclone


  Flooding is aggravated and can cause more damage
• Urban Flooding


  Usually occur in highly populated, developed areas set on relatively low lying areas
• Causes of Urban Flooding

  • Saturation of the ground due to too much rainfall
  • Presence of large areas of impermeable surfaces like concrete pavements and rooftops