Hydrometeorological Hazards

• HYDROMETEOROLOGICAL - isa 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 include:Typhoon , Thunderstorm, Flood, flashflood, Storm Surge, El Niño and La Niña
• 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.
• Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA)
• WEATHER FORECAST is a scientific estimate of future weather condition, wherein a weather condition is a state of the atmosphere at a given time expressed in terms of the most significant variables. I
• 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.
• 1st Step: 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.
• 2nd Step: 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
• 3rd Step: 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
• 4th Step: Analysis of Weather Maps, Satellite and Radar Imageries and Other Data - Current weather maps are analyzed through different weather charts namely SURFACE (MSL) CHART, where data plotted on this weather map are analyzed isobarically
• 5th Step: Formulation of the Forecast - Upon completion of review of all available meteorological information / data, the preparation of forecasts follows.
• Thunderstorm forms through 3 stages known as CUMULUS STAGE, MATURE STAGE and 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 & FLASHFLOOD - Flood is a high-water stage in which water overflows its natural or artificial banks onto normally dry land, such as a river inundating its floodplain. The effects of floods on human well-being range from unqualified blessings to catastrophes.
• FLASH FLOOD - Flash flood is an event that occurs suddenly with little warning.
• Inland flooding is the technical name for ordinary flooding that occurs in inland areas, hundreds of miles from the coast.
• Flash floods are 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 neighboring land.
• Coastal flooding is 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 or "Daluyong ng Bagyo" in the Philippine system where the irregular sea-level rise during tropical cyclone or "bagyo" occurs. When the tropical cyclone reaches the coast, powerful winds force the ocean water over the coastal low-lying areas, which can lead to flooding.
• storm surge color - warning system: storm surge is catastrophic there is significant threat to life. Mandatory evacuation is enforced. Color: Red(take action). 3 meters above
• storm surge color - coded warning system: Storm surge is expected. Condition could become life threatening. All marine activities must be cancelled. Follow evacuation guidelines from local authorities. Color: Orange (alarm). 1.1 to 3 meters
• storm surge color - coded warning system: storm surge is possible: stay away from the coast or the beach. Preparation measure should be carried out. color: yellow (alert). 0.5 to 1 meter
• storm surge color - coded warning system: No action required. Color: Green
• EL NIÑO - means The Little Boy, or Christ Child in Spanish. El Niño was originally recognized by fishermen off the coast of South America in the 1600s, with the appearance of unusually warm water in the Pacific Ocean. The name was chosen based on the time of year (around December) during which these warm waters events tended to occur.
• LA NIÑA – means The Little Girl in Spanish. La Niña is also sometimes called El Viejo, anti-El Niño, or simply "a cold event."
• The term El Niño refers to the large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperatures across the central and east-central Equatorial Pacific.
• La Niña episodes represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific. Global climate La Niña impacts tend to be opposite those of El Niño impacts. In the tropics, ocean temperature variations in La Niña also tend to be opposite those of El Niño.
• Hydro meteorological hazards represents periods of belowaverage sea surface temperatures across the east-central Equatorial Pacific. La Niña
• Hydro meteorological hazard is characterized by localized storm cloud that produces lightning and thunder, and often brings heavy rain shower and strong gusty winds. Thunderstorm
• It is a predicting sign of a typhoon where a rotating wall cloud with a lowered cloud base is characteristic of a severe thunderstorm (supercell). It’s the most obvious sign of a severe storm: twisting, rotating, and unusually quick-moving clouds. Cloud location and sun rays
• an overflow of water onto normally dry land in an existing waterway, such as a river, stream, or drainage ditch. Flood
• Refers to the large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperatures across the central and eastcentral Equatorial Pacific. El Niño
• It is a predicting sign of a typhoon where clouds are often seen as fluffy, fair-weather cotton balls in the sky. arching shelf clouds
• A violent, short-lived weather disturbance that is almost always associated with lightning, thunder, dense clouds, heavy rain or hail, and strong, gusty winds. Storm surge
• It is the stage wherein the sun heats the Earth's surface during the day. The heat on the surface and warms the air around it. Cumulus stage
• It is the stage when the cumulus cloud becomes very large, the water in it becomes large and heavy. Raindrops start to fall through the cloud when the rising air can no longer hold them up. Mature stage