W2

• Hydrometeorological Phenomena

  • essential to life on Earth, can be beneficial and detrimental
  • changes in hydrological cycle can be hazardous
• Hydrometeorological Hazards

  • tropical cyclones
  • hailstorms
  • thunderstorms
  • avalanches
  • tornados
  • sblizzard
  • heavy snowfall
  • floods
  • drought
  • heatwaves
  • cold spells
  • coastal storm surges
• Typhoon

  • a severe weather disturbance characterized by strong winds and heavy rains revolving around low pressure areas.
  • the most powerful type of tropical cyclone formed in north western pacific ocean
• Typhoon came from the Chinese term Tai (big) and fung (wind)

  • it is locally known as bagyo
• PARTS OF AN LPA

  Eye - the area with the lowest atmospheric pressure

  Eyewall - the region surrounding the tropical cyclone's center. It brings the strongest winds, heavy rains, and turbulence shortly after the passage of the eye. It can reach 15 km above mean sea level

  Rainbands - the spiraling strips of clouds
• • Cooler high-altitude temperatures form cumulonimbus clouds.
  • Drier high-altitude air forms the storm’s “eye.”
  • Hurricane winds circle the eye, and trade winds push the storm along its track.
• Storm surge

  • a localized unusual increase in sea water level beyond predicted astronomical tide level due to intense winds and lower atmospheric pressure during the passage of an intense tropical cyclone from the sea to the land.
• Storm surge risk-reduction measures

  1. Storm surge prediction, hazard map preparation and zoning
  2. Construction of storm surge barriers
  3. Wetland protection
• PAGASA'S STORM WARNING SYSTEM

  SIGNAL NO. 1 - winds of up to 30-60 kph in the next 24 hours

  SIGNAL NO. 2 - winds of up to 61-120 kph in the next 24 hours

  SIGNAL NO. 3 - winds of up to 121-170 kph in the next 18 hours

  SIGNAL NO. 4 - winds of up to 171-220 kph in the next 12 hours

  SIGNAL NO. 5 - winds exceeding 220 kph in tthe next 12 hours
• TROPICAL CYCLONE CLASSIFICATION:

  1. TROPICAL DEPRESSION - winds up to 61 kph
  2. TROPICAL STORM - winds of up to 62-88 kph
  3. SEVERE TROPICAL STORM - winds of up to 89-117 kph
  4. TYPHOON - winds of up to 118-220 kph
  5. SUPER TYPHOON - winds exceeding 220 kph
• Thunderstorms

  • a violent, transient type of weather disturbance associated with tall cumulonimbus clouds, usually involving lightning and thunder, strong winds, intense rainfall, and occasionally tornadoes and hail
• Flood - the abnormal rise in water level in rivers, coastal areas, plains, and in highly urbanized centers which may be a result of natural phenomena, human activities, or both.
• Flood causes


  1. Increased Urbanization

  2. Bad Farming Practice

  3. Deforestation
• Increased Urbanization


  Leads to more surface runoff into urban areas due to hard, impermeable surfaces. This results in less water infiltration into the ground and an increase in the volume and rate of surface runoff.
• Bad Farming Practice


  Some farmers contribute to soil and topsoil runoff into rivers by leaving fields bare and using machinery with cutting edges facing down. Ploughing in the wrong direction can also cause this issue.
• Deforestation


  Responsible for the loss of vegetation and soil. Vegetation acts like a sponge, absorbing most of the water when it rains, but deforestation reduces this capacity.
• El Niño Southern Oscillation(ENSO)

  • a natural climatic phenomenon characterized by cylic fluctuation of warm and cold sea surface temperature and atmospheric pressure in central and eastern equatorial pacific.
• El Niño - impacts weather systems around the globe, triggering predictable disruptions in temperature, rainfall, and winds.
• La Niña - a cooling phase of ENSO that tends to have global climate impacts opposite to those of El Niño
• Hurricane - Atlantic and Northeast Pacific

  Typhoon - Northwest Pacific

  Cyclone - South Pacific and Indian Ocean
• Types of clouds:

  1. Cumulonimbus clouds - an extremely dense, vertically developed cloud with a low, dark base and fluffy masses that tower to great heights. It produces heavy rains.
  2. Stratus clouds -a flat, hazy, featureless clouds at low altitudes varying in color from dark gray to nearly white
  3. Nimbus clouds - refers to rain clouds, or clouds that carry significant amounts of precipitation
  4. Cumulus clouds - fluffy, white clouds with a distinct puffy appearance