Flash Flood Guidance System (FFGS) with Global Coverage


  • U.S. Agency for International Development/Bureau for Humanitarian Assistance (USAID/BHA
  • Climate Risk Early Warning System (CREWS
  • Environment and Climate Change Canada (ECCC)

Project Partners:

  • World Meteorological Organization (WMO)
  • National Oceanic and Atmospheric Administration (NOAA
  • National Weather Service (NWS
  • Hydrologic Research Center (HRC)

Flash floods are among the world’s deadliest natural disasters with more than 5,000 lives lost annually. Their social, economic and environmental impacts are significant. Accounting for approximately 85% of flooding cases, flash floods also have the highest mortality rate among different classes of flooding, including riverine and coastal.

Flash floods differ from river floods in their short time scales and occurrence on small spatial scales, which makes flash flood forecasting a different challenge from large-river flood forecasting. In flash floods forecasting, we are concerned foremost with the forecast of occurrence, and herein focus on two causative events: 1) intense rainfall; and 2) rainfall on saturated soils. Flash floods occur throughout the world, and the development times vary across regions from minutes to several hours depending on the land surface, geomorphological and hydrometeorological characteristics of the region. However, for the majority of these areas, there exists no formal process or capacity for developing flash flood warnings.

To address the issues associated with flash floods, especially the lack of capacity to develop effective flash flood warnings, the Flash Flood Guidance System (FFGS) was designed and developed for interactive use by meteorological and hydrological forecasters throughout the world. In support of the FFGS project, a Memorandum of Understanding was signed by the WMO, the U.S. Agency for International Development/Office of U.S. Foreign Disaster Assistance (USAID), the U.S. National Oceanic and Atmospheric Administration/National Weather Service (NOAA) and the Hydrologic Research Center (HRC) to work together under a cooperative initiative to implement the FFGS worldwide. The FFGS project is a public benefit effort on behalf of the partners.

FFGS is necessary to provide operational forecasters and disaster management agencies with real-time informational guidance products pertaining to the threat of small-scale flash flooding. FFGS is a robust system designed to provide the products needed to support the development of flash flood warnings from rainfall events using remote-sensed precipitation (that is, radar and satellite-based rainfall estimates) and hydrological models. To assess the threat of a local flash flood, FFGS allows product adjustments based on the forecaster’s experience with local conditions; incorporation of information, such as Numerical Weather Prediction (NWP) outputs; and any last minute local observations, including non-traditional rain gauge data or local observer reports.

FFGS with Global Coverage
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Recognizing that flash floods have a particularly disastrous impact on lives and properties of the affected populations, the Fifteenth WMO Congress had approved the implementation of a Flash Flood Guidance System (FFGS) project with global coverage that had been developed by the WMO Commission for Hydrology (CHy) jointly with the WMO Commission for Basic Systems (CBS) and in collaboration with the U.S. National Weather Service, the US Hydrologic Research Center (HRC) and USAID/OFDA (currently, USAID/BHA).

Regional and National FFGS projects

Within the scope of the FFGS implementation, the following regional and national projects have been implemented or are under implementation:

  • Black Sea and Middle East FFGS (operational): Armenia, Azerbaijan, Bulgaria, Georgia, Jordan, Lebanon, Israel and Turkey (RC);
  • Central Asia Region FFGS (operational): Kazakhstan (RC), Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan;
  • Central America FFGS (operational): Costa Rica (RC), Belize, El Salvador, Guatemala, Honduras, Nicaragua and Panama;
  • Chiapas Mexico FFGS
  • Fiji FFGS (operational):
  • Haiti and Dominican Republic FFGS (operational): Dominican Republic (RC) and Haiti;
  • Mekong River Commission FFGS (operational): Cambodia (RC is Mekong River Commission (MRC)), Lao People's Democratic Republic, Thailand and Viet Nam;
  • Myanmar FFGS (operational): Myanmar
  • Northwest South America FFGS (under development): Colombia, Ecuador, Peru
  • Southern Africa Region FFGS (operational): Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa (RC), Eswatini, Zambia and Zimbabwe;
  • Pakistan and Afghanistan Regional FFGS (under implementation): Pakistan (RC) and Afghanistan;
  • South Asia FFG (operational): Bangladesh, Bhutan, India (RC), Nepal and Sri Lanka;
  • Southeast Asia FFG (under development): Cambodia, Lao People's Democratic Republic, Thailand and Viet Nam (RC);
  • Southeastern Asia-Oceania FFGS (operational): Brunei Darussalam, Indonesia (RC), Malaysia, Papua New Guinea, Philippines, Singapore, and Timor-Leste;
  • South East Europe FFGS (operational): Albania, Bosnia and Herzegovina, Croatia, Moldova, Montenegro, Romania, Serbia, Slovenia, North Macedonia, and Turkey (RC);
  • West Africa FFGS (under development): Burkina Faso, Mali and Niger.

A number of them have already been implemented, while others are under implementation, currently covering sixty four countries throughout the world.


  • enhance the capacity of National Meteorological and Hydrological Services (NMHSs) to issue effective flash flood warnings and alerts;
  • enhance collaboration between NMHSs and Emergency Management Agencies;
  • foster national and regional development and collaboration;
  • generate flash flood early warning products by using the hydrometeorological forecasting models;
  • provide extensive training, including online training, to forecasters; and
  • support the WMO Flood Forecasting Initiative.

Training Program

For more information about the extensive FFGS training program and the Moodle platform, please click on the image below:

FFGS online training platform

FFGS Sustainability Strategy

Based on the findings of an external Review of the Global FFGS that was completed in 2018, the outcomes of the Global FFGS Workshop held in 2019, experience gained in forecasting and provision of warnings of flash floods, the insights of the FFGS Partners and the authors of the report, and the suggestions of the report’s many reviewers, FFGS Partners jointly with Standing Committee on Hydrological Services (SC-HYD) and FFGS National and Regional Centres, developed FFGS Sustainability Strategy with the goal of providing the vision and approaches to be taken to help attain sustainability of the FFGS.

Sustainability Strategy for the FFGS identified four critical factors, which are needed to achieve the much-desired sustainability.

These four factors are:

  • Developing an inclusive and broadened governance model;
  • Increasing and strengthening the training effort;
  • Increasing visibility of the FFGS; and
  • Developing additional financial and human resource support.

Sustainability Strategy for the FFGS will be finalized and presented at WMO Congress in October 2021 (Cg-Ext 2021). 

To obtain more information please watch the video below or contact WMO at: ffgs@wmo.int