HYDROMETEORLOGICAL

• HYDRO METEOROLOGICAL HAZARDS DISASTER READINESS AND RISK REDUCTION – GRADE 11 PROPHET ISAIAH
• Hydrometeorological


  A process or phenomenon of atmospheric, hydrological or oceanographic nature that may cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage
• Hydrometeorological hazards


  • Typhoon
  • Thunderstorm
  • Flood
  • Flashflood
  • Storm Surge
  • El Niño
  • La Niña
• Typhoon


  Tropical cyclone, also called typhoon or hurricane, an intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain
• PAGASA


  Philippine Atmospheric Geophysical and Astronomical Services Administration
• Weather Forecast


  A scientific estimate of future weather condition
• How is a Weather Forecast Made?

  1. Done by a Meteorologist

  2. Must know about the existing weather condition over a large area

  3. The accuracy of forecast decision is based on forecasting tools known as the Weather Map
• Weather Forecasting Steps


  1. Observation

  2. Collection and Transmission of Weather Data

  3. Plotting of Weather Data

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

  5. Formulation of the Forecast
• Observation


  A meteorologist forecasts weather decision through surface observations at least every three hours over land and sea, and upper air stations at least every twelve hours. A numerical weather prediction - fed to the computer which analyzes data as programmed and makes a time integration of physical equations
• Collection and Transmission of Weather Data

  Collection and Transmission of Weather Data are condensed into coded figures, symbols and numerals are transmitted via radiophone, teletype, facsimile machine or telephone to designated collection centers for further transmission to the central forecasting station
• Plotting of Weather Data

  Observations on land and sea are plotted on charts of surface or mean sea level, which are prepared four times a day. Once the coded messages have been received, they are decoded, and each set of observations is plotted over the respective areas or regions in symbols or numbers on weather charts
• Analysis of Weather Maps, Satellite and Radar Imageries and Other Data

  1. SURFACE (MSL) CHART, where data plotted on this weather map are analyzed isobarically. This means the same atmospheric pressure at different places are interconnected with a line taking into consideration the direction of the wind

  2. UPPER AIR CHARTS, data plotted on this weather map are analyzed using streamline analysis

  3. Numerical Weather Prediction model output- the computer-plotted weather maps are analyzed manually so that weather systems like cyclones and anticyclones are located

  4. MONITOR WEATHER CHARTS - plotted cross-section data, rainfall charts and 24 hour pressure change charts are analyzed to determine wind wave movement, rainfall distribution and atmospheric pressure behavior
• Formulation of the Forecast


  Upon completion of review of all available meteorological information / data, the preparation of forecasts follows. The first and one of the preliminary steps is to determine the position of the various weather systems and the actual weather over a given area as accurately as the data permits
• PAGASA PUBLIC STORM WARNING SIGNAL SYSTEM

  • PUBLIC STORM SIGNAL NO. 1
  • PUBLIC STORM SIGNAL NO. 2
  • PUBLIC STORM SIGNAL NO. 3
• PUBLIC STORM SIGNAL NO. 1

  Tropical cyclone will affect an area. Winds of 30-60 kph are expected. Intermittent rains may be expected in at least 36 hours. Twigs and branches of small trees may be broken. Some banana plants may be tilted or uprooted. Some houses of very light materials may be partially unroofed. Classes in preschool are suspended. When the tropical cyclone intensifies and moves closer, this warning signal number may be upgraded
• PUBLIC STORM SIGNAL NO. 2


  Tropical cyclone will affect an area. Winds of greater than 60 kph and up to 100 kph may be expected in at least 24 hours. Some coconut tress may tilt; some of them may break. Few big trees may be uprooted. Classes in the primary and secondary levels of education are suspended. The sea and coastal waters are dangerous to small seacraft. Many banana plants may be downed. Rice and corn crops may be affected. Special attention should be given to the latest position, direction and movement speed, and intensify of the storm as it moves toward an area. The public especially people traveling by sea and air are cautioned. A large number of houses made of light materials may be unroofed. Old galvanized iron roofing may be peeled off. In general, the winds may bring light to moderate damage to the exposed communities. Outdoor activities of children should be postponed. Secure properties before the signal is upgraded
• PUBLIC STORM SIGNAL NO. 3

  Tropical cyclone will affect an area. Winds of greater than 60 kph and up to 100 kph may be expected in at least 18 hours. Many coconut trees may be broken or destroyed. Almost all banana plants may be downed and a large number of trees may be uprooted. Rice and corn crops may suffer heavy losses. Majority of light material houses may be unroofed or destroyed. There may be considerate damage to structures of light to medium construction. All classes up to tertiary level education (college and universities) are suspended. The weather condition is dangerous to the communities affected. The sea and coastal waters will be very dangerous to all seacraft. Travel is very risky especially by air and sea. People are advised to seek shelter in strong buildings, evacuate low-lying areas, and stay away from the coasts and riverbanks. There may be widespread disruption of electrical power and communication services. In general, moderate to heavy damage may be experienced, particularly in the agricultural and industrial sectors. Watch out for the passage eye of the typhoon indicated by a sudden occurrence of fair weather immediately after very strong winds coming generally from the north
• Thunderstorm


  This is a powerful, short-lived weather disturbance, almost always associated with lightning, thunder, dense clouds, heavy rain or hail, and fast, roaring winds. Thunderstorms occur when layers of dry, moist air rise to cooler regions of the atmosphere in a broad, rapid updraft
• 3 Stages of Thunderstorm

  1. Cumulus Stage

  2. Mature Stage

  3. Dissipating Stage
• Cumulus Stage


  Where the sun heats the Earth's surface during the day and warms the air around it
• Mature Stage


  A cumulus cloud becomes very large, where the water therein becomes large and heavy, and raindrops begin to fall through the cloud when the rising air can no longer hold them up
• Dissipating Stage


  After 30 minutes, thunderstorm begins to dissipate, this occurs when the downdrafts in the cloud begins to dominate over the updraft. Since warm moist air can no longer rise, cloud droplets can no longer form
• Flood


  A high-water stage in which water overflows its natural or artificial banks onto normally dry land, such as a river inundating its floodplain
• Types of Floods


  • Inland Flooding
  • Flash floods
  • River Flooding
• Inland Flooding


  The technical name for ordinary flooding that occurs in inland areas, hundreds of miles from the coast
• Flash floods


  Caused by heavy rain or the sudden release of water over a short period of time. The name "flash" refers to their fast occurrence and also to their raging torrents of water that move with great speed. Flash floods are also caused by heavy precipitation in a short period of time, usually less than 6 hours
• River Flooding


  Occurs when water levels in rivers, lakes, and streams rise and overflow onto the surrounding banks, shores, and ne
• Dissipating Stage of a Thunderstorm

  1. Downdrafts in the cloud begin to dominate over the updraft

  2. Warm moist air can no longer rise

  3. Cloud droplets can no longer form
• Types of Floods


  • Inland Flooding
  • Flash Floods
  • River Flooding
  • Coastal Flooding
  • Urban Flooding
  • Storm Surge
• Flash Floods


  Caused by heavy rain or the sudden release of water over a short period of time, with fast occurrence and raging torrents of water that move with great speed
• River Flooding


  Occurs when water levels in rivers, lakes, and streams rise and overflow onto the surrounding banks, shores, and neighboring land
• Coastal Flooding


  The inundation of land areas along the coast by seawater
• Urban Flooding


  Occurs when there is a lack of drainage in an urban (city) area
• Storm Surge


  The irregular sea-level rise during a tropical cyclone or "bagyo", where powerful winds force the ocean water over the coastal low-lying areas, leading to flooding
• El Niño


  Means "The Little Boy" or "Christ Child" in Spanish, originally recognized by fishermen off the coast of South America in the 1600s as unusually warm water in the Pacific Ocean, occurring around December
• La Niña


  Means "The Little Girl" in Spanish, also called El Viejo, anti-El Niño, or a cold event
• How are you going to prepare yourself in times of the occurrence of hydrometeorological hazards?
• Appropriate Measures BEFORE Any Hydrometeorological Hazard

  1. Stay enough food, drinking water, and medicine

  2. Have a working flashlight, spare batteries, candles, and matches ready

  3. Meet with family and make evacuation plans

  4. Reinforce the roofs, windows, and structural supports or foundations of your house

  5. Transfer valuables, appliances, and furniture to a higher ground

  6. Participate in cleanup activities to clear waterways

  7. Remove dead or rotting trees and branches
• Appropriate Measures DURING Any Hydrometeorological Hazard


  1. Stay indoors, keep calm, and do not go to isolated or open areas

  2. Listen to weather updates and advisories

  3. Unplug electrical equipment and switch off the main circuit breaker or fuse box if water is rising

  4. Move to a safer ground or evacuate as advised by local authorities

  5. Bring basic necessities to the evacuation site

  6. Beware of open electrical cables and power surges

  7. Do not go near windows or doors
• Appropriate Measures AFTER Any Hydrometeorological Hazards


  1. Wait for announcements from local authorities on safety to return home

  2. Report fallen power lines or cracked roads to local authorities

  3. Check your house for damage and do needed repairs immediately

  4. Have a licensed electrician or knowledgeable person inspect electrical connections and appliances before use

  5. Boil water before drinking as it may be contaminated