Signs of Hydrometerological Hazards

• Hydrometeorological hazards

  Weather-related hazards
• Heavy rains continue to hit some parts of metro manila today
• The southern downpours are due to the habagat or the southwest monsoon which is enhancing a low pressure area near vietnam
• The lpa won't directly hit the country but heavy rains are still expected in metro manila particularly in pasai and taguig
• The western section of luzon will also be affected including the ilocos region, bataan, zambales, pangasinan, batangas, as well as mindoro and palawan
• Visayas and mindanao will also be under cloudy skies with light to moderate showers
• There's no storm in the philippine area of responsibility but we should always be prepared
• Last year the habagat left a massive trail of devastation in metro manila and parts of luzon
• Pagasa expects one more storm this month and 10 to 15 more storms within the year
• Tropical cyclone

  A rotating organized system of clouds and thunderstorms that originates over tropical waters
• Tropical cyclones

  • Rotate in counterclockwise direction in the northern hemisphere, and clockwise in the southern hemisphere
  • Usually move to the west and generally tightly pole ward
  • Can change direction and recurve
• Tropical cyclone


  • Typhoon tip (1979 pacific typhoon season)
• Classification of tropical cyclones by strength (according to pagasa)

  • Tropical depression (up to 61 km/h)
  • Tropical storm (62-88 km/h)
  • Severe tropical storm (89-117 km/h)
  • Typhoon (118-200 km/h)
  • Super typhoon (over 220 km/h)
• An average of 19 tropical cyclones enter the philippine area of responsibility each year, with 9-10 making landfall
• Satellite image of tropical cyclone

  Characteristic spiral or circular shape, with a distinctive cloud-less eye at the center
• Weather radar


  Used to track movement and estimate intensity of tropical cyclones
• Tropical cyclone forecast by pagasa

  1. 5-day forecast track issued every 6 hours

  2. Public storm warning system (psws) issued to warn of impending wind strength
• Public storm warning system (psws) levels

  • Signal no. 1 (30-60 km/h winds)
  • Signal no. 2 (61-88 km/h winds)
  • Signal no. 3 (89-117 km/h winds)
  • Signal no. 4 (118-170 km/h winds)
  • Signal no. 5 (over 170 km/h winds)
• Rainfall advisory levels

  • Red warning (over 13 mm rain)
  • Orange warning (heavy rain, flooding possible)
  • Yellow warning (heavy rain)
• Class suspensions are announced based on the public storm warning system
• "recurvature"


  move into the mid-latitude and back toward the east
• The intensity of tropical cyclones vary. Thus, it can be classified based on its intensity.
• RADAR


  RAdio Detection And Ranging
• RADAR

  • sends out electromagnetic waves to the atmosphere reflected by hydrometeors
  • limited to a range of approximately 400 km of the radar site
• Forecast


  gives the expected location of tropical cyclone in the succeeding 24-hour interval
• 5-day forecast every 6 hours


  5am, 11am, 5pm, 11pm
• PSWS

  Public Storm Warning System
• Signal No. 1


  No classes in Kindergarten
• Signal No. 2


  No classes in Elementary and High School
• Signal No. 3


  No classes in ALL LEVELS (including tertiary level)