How to use PAGASA’s color-coded rainfall advisory
MANILA, Philippines - Every year, around 20 tropical cyclones visit the country, making flood a perennial problem for Filipinos.
In 2012, state weather bureau Pagasa released a new set of color-coded rainfall advisories. It is composed of 3 colors: Yellow, Orange and Red. The darker the color is, the more dangerous it gets.
Below is an infographic explaining Pagasa's rainfall advisories.
What do the colors mean?
This means heavy rainfall of 7.5 - 15 mm in an hour is observed and is expected to continue for the next 2 hours. This can be equivalent to 2 gallons of rain per square meter per hour.
When Pagasa gives yellow advisory, it means that residents in affected areas should continue monitoring their weather condition. Flooding for low-lying areas is possible.
This means intense rainfall of 15-30mm in an hour is observed and is expected to continue for the next 2 hours. This can be equivalent to 4 to 8 gallons of rain per square meter per hour.
When Pagasa gives orange advisory, it means that residents in affected areas should be on alert for possible evacuation. Flooding in affected areas is expected.
This means torrential rainfall of more than 30mm in an hour is observed and is expected to continue for the next 2 hours. This can be equivalent to 8 gallons of rain per square meter per hour.
Continuous rainfall of more than 65mm for 3 hours can also prompt Pagasa to give this advisory.
When Pagasa gives red advisory, it means that severe flooding in low lying areas is expected and residents should start evacuating.
Stay tuned for advisories
Here’s a sample advisory from its Facebook account:
Once an advisory is issued in your area, check the real-time flood situation in your area by going to Project Noah website.
Then, go to Flood Map menu and click Flood Inundation - where you can find the real-time situation in different river basins. Choose whichever is near your area.
Depending on the water level of the river, you might see the river overflowing to nearby areas. This means that there is flooding in areas where the water reaches.
The flood scenario per river basin is updated every 10 minutes.
Why look at the river basins?
River basins play a major role in possible flooding in an area. Every time there is rain, the rainwater normally goes to the rivers, then eventually to the seas. But if the rainfall is too much, then the river basin may spill and cause flooding in low-lying areas near it.
"Pag pinagaaralan mo yung flooding [sa lugar mo], siyempre yung pag-ulan doon sa kabilang river basin will not affect yung analysis mo ng flooding doon sa [river] basin na pinag-aaralan mo," (When you analayze flooding [in your area], of course, the rainfall situation in other basins will not affect your analysis on the [river] basin in your area) Dr. Mahar Lagmay, executive director of Project Noah said.
The new color-coded advisories aim to help local governments and their communities to prepare for floods, landslides, and dam spills.
For more information on Project Noah, watch these two 10-minute Project Noah website tutorial videos that Lagmay prepared.
If you have any questions, feedback, or additional information, please email firstname.lastname@example.org or tweet @moveph.
Project Agos is a collaborative platform that combines top-down government action with bottom-up civic engagement to help communities learn about climate change adaptation and disaster risk reduction. The project harnesses technology and social media to ensure critical information flows to those who need it before, during, and after a disaster. It is a partnership between Rappler and key government, private and civil society groups. It is also supported by the Australian Government.