Hydrometerological

• Hydrometeorological hazards - Are process which involve the interaction of the atmosphere, bodies of water and land and which pose threats o lives and human property.
• Tropical cyclone - are low pressure systems that form over warm tropical waters. They typically form when the sea-surface temperature is above 26.5°C
• hurricanes -North Atlantic, Eastern north Pacific and South Pacific Ocean
• Cyclonic - In the bay of Bengal, Arabian Sea and Western South Indian Ocean.
• Willy willy - In the eastern part of the Southern Indian Ocean
• Typhoons - Western North Pacific Ocean
• A tropical cyclone on average, has a total diameter of 550 km but can have a diameter more than 2000 km wide.
• EYE – has the lowest atmospheric pressure in the structure of a tropical cyclone.  Has a diameter which spans from 20-65 km wide, characterized by weak winds, warm temperature and a clear sky.
• EYE WALL – the region immediately surrounding the tropical cyclone’s center which can reach as high as 15 km above sea level, bringing strongest winds, heavy rains, and turbulence shortly after the passage of the eye.
• RAIN BANDS – the spiraling strips of clouds in the fringes of the TC which associated with rainfall.
• Effects of tropical cyclone

  • Strong Winds
  • Storm Surge
  • Heavy Rains
• Tropical cyclone can be distinguished according to their maximum sustained-wing speed(over 10-minute periods)
• Tropical depression - (wind speed 61 kph or less)
• Tropical Strom - (wind speed ranging from 62-88 kph)
• Severe Tropical Storm - (89- 117 kph )
• Typhoon -(wind speed greater than 118-184 kph)
• Super typhoon - (wind speed exceeding 185 or higher kph)
• Increased ocean swell – A swell is a series of ocean waves brought about by strong winds. An incoming typhoon would cause a swell of about a meter in height that hit the shore every 10 seconds. As the typhoon approaches the waves to come in much faster and may also increase in height.
• Changes in clouds – Cumulus clouds may fill the sky about 36 hours before a typhoon. As the storm approaches, the sky could be clear of clouds and may later have a mass of cirrus clouds which appear as a veil covering the horizon, eventually covering a large portion of the sky. A few hours before the typhoon landfall, low-lying clouds form which slowly become thick and dark, usually accompanied by rain.
• Barometric pressure drop – the atmospheric pressure may start to drop about 36 hours before typhoon landfall. This will continue as the storm approaches.
• Abrupt changes in wind speed – wind speed increases due to the drop in atmospheric pressure as air moves from an area with high pressure to low pressure. The increase in wind speed also increases the height of the ocean swell.
• Storm surge - a localized unusual increase of sea water level beyond the predicted astronomical tide level primarily due to intense winds and lowered atmospheric pressure during the passage of an intense tropical cyclone from sea to land
• Thunderstorm - A violent , transient type of weather disturbance associated with thousands of cumulonimbus clouds at which usually involves lightning and thunder, strong winds , intense rainfall and occasionally tornadoes and hail.
• Hazard associated with thunderstorm

  • Lightning
  • Hail
  • Tornadoes
  • Flash floods
• Flooding - the abnormal rise of water level in rivers, coastal areas, plains and in highly urbanized centers which may be a result of natural phenomena, human activities or both
• El Niño means Little Boy in Spanish. South American fishermen first noticed periods of unusually warm water in the Pacific Ocean in the 1600s. The full name they used was El Niño de Navidad, because El Niño typically peaks around December
• El Niño - refers to the large-scale ocean-atmospheric climate interaction linked to a periodic warming in sea surface temperature across the central and east-central Equatorial Pacific.
• La Niña means Little Girl in Spanish. La Niña is also sometimes called El Viejo, anti-El Niño, or simply "a cold event.“
• La Niña - is a climate pattern that describes the cooling of surface-ocean water along the tropical west coast of South America.
• Barograph - a barometer that reads and records atmospheric pressure continuously
• Thermograph - an instrument that measures and record air temperature continuously
• Ceiling light projector - an instrument that projects a light beam to the clouds
• Clinometer - an instrument that determine the height of the clouds base by measuring the distance of the cloud base to the ground
• Ceiling balloon - a balloon filled with hydrogen or other gas lighter than air, which is used to determine the height of the cloud base
• Theodolite - an instrument that determines wind speed and direction.
• Radiosonde - an instrument attached to a balloon and is used to measure temperature, pressure, and relative humidity in the atmosphere. It is equipped with a transmitter that sends data to a radiosonde receiver on the ground.
• Wind finding radar - it measures wind speed and direction thru radar echoes. It works by attaching a radar target to a balloon that is sent to the atmosphere. The time interval and bearing of the radar echoes are evaluated by a receiver ground radar
• Weather Surveillance Radar - it detects and monitors the track of typhoons and cloud masses within 400 kilometers.
• Doppler Radar - calculates the motion of precipitation, estimates its type, and determines the structure of storms and their potential to cause severe weather
• Weather Satellite - provides the synoptic view and coverage area of a weather disturbance and the capability to relay weather data from remote automatic weather stations