NEC06809 NFLICS: Nowcasting FLood Impacts of Convective storms in the Sahel

NFLICS (Nowcasting FLood Impacts of Convective storms in the Sahel) replies to the pressing demands of on-the-ground responders and risk groups for advance warnings of heavy rainfall and likely flood impact. In the Sahel, the vast majority of flash floods are due to intense rain within long-lived Mesoscale Convective Systems (MCSs). The most powerful MCS have tripled in frequency over the last 35 years in this region, apparently linked to global warming. This climate change signal has been accompanied by rapid urban expansion in the region, and indicates that the socio-economic impacts of flash flooding are likely to become even more devastating in the coming years. As a consequence, civil protection authorities and on-the-ground responders in the Sahel are demanding improved early warnings of the likelihood of flood impact through proven tools and services from National Meteorological and Hydrological Services (NMHS). NFLICS will address this need by developing and testing automated approaches for predictions out to 6 hours of intense rain and likely flood impact in Senegal. It will work in partnership by engaging widely to co-develop decision-relevant products and processes for operational services that meet the demands of the user community.

NFLICS will exploit state-of-the-art research findings from satellite analysis that have identified land surface drivers of extreme MCS rainfall, opening up the potential for improved probabilistic nowcasting of intense rain and flooding. Statistical analysis of historical flood events can link these probabilistic nowcasts to likely urban flood damage and thus provide novel forecasts of flood risk, based on recent methods advanced in the UK. Information at shorter timescales has the potential to improve resilience and adaptation planning to extreme rainfall events. The project will be led by the Centre for Ecology & Hydrology (CEH) and, for this catalyst grant, Senegal will be the case study country. However, the methods developed will be open, scalable and transferable to other countries in the Sahel and beyond. This will be aided by primarily using Near Real-Time (NRT) satellite data that are readily available to forecasters in African countries. The project plan has been developed in partnership with ANACIM, the national meteorological agency of Senegal, who will also be a key beneficiary of the research outputs and capacity building funded by the work. Knowledge Exchange activities are a key component and stakeholder participation will be led by experts from VNG, CEH and IED-Afrique to ensure user-led design of services by facilitating engagement with users and promoting two-way dialogues. NFLICS will deliver a 2 year programme of activity that will culminate in a real-time trial of the new rainfall and flood risk nowcast products during the 2020 wet season. This will be reviewed by all partners and will inform operational implementation plans. The findings will be widely shared amongst other Sahel countries, and beyond, to promote wider uptake and benefit of the project outputs.

The impact of NFLICS comes from a significant improvement in the flood risk early warning ability of national agencies. Improved forecast skill at short timescales, available at city and sub-national spatial scales, enables better preparedness to climate-related hazards. The development of this research project was driven through long-standing partnerships that identified the need for improved rainfall and flood nowcasts and greater capacity to predict flood events. NFLICS results will be translatable beyond Senegal to other regions of Africa and the developing world more widely.

In recent decades West Africa has experienced some of the most extreme rainfall variability anywhere in the world with severe impacts resulting from flooding. Climate change and rapid population growth heighten these risks. Better access to reliable, relevant information underpins effective planning towards mitigation and adaptation. However, low confidence in, and use of, climate information partly stems from inadequate communication between climate information providers and users. Supporting the consideration of climate extremes and understanding of forecast uncertainties by decision makers can provide a substantial contribution to strengthening resilience to climate risks.

In Senegal the Civil Protection Directorate is responsible for responding to emergencies, and works with the National Committee for Flood Management to determine the necessary course of action at times of flooding. Both carry out risk planning and work with ANACIM to monitor critical developments during flood events. Predicting the occurrence of intense rainfall is a very challenging problem, hampering flood preparedness activities. Through its public weather service, ANACIM are mandated to deliver forecasts for Senegal and its 14 regions tailored to support key sectors and government departments, including transportation, agriculture, fisheries and disaster preparedness. To rapidly get information to at-risk people, ANACIM delivers SMS warnings and advisories to a network of trained focal points who communicate weather related hazards to local communities. To strengthen this network, we will assess user needs and ensure this informs the technical tasks of NFLICS.

Specific Beneficiaries are:
A. The research community benefits from increased research capability of forecasting in the tropics plus strengthened understanding of the processes for developing decision-relevant climate services.
B. Weather and climate agencies in Senegal benefit directly from the research, training and collaborations. Research capacity and tools will be developed in partnership between the UK and Senegalese partner organisations for use beyond this project.
C. Decision-making organisations will benefit from: i) Improved decision-relevant flood forecasts ii) Strengthened understanding of forecast products, uncertainties and how this information can support enhanced risk management iii) Timely access to flood forecasts.
D. At-risk people and the wider public will benefit from improved forecasts, strengthened risk management systems, and an enhanced communication network involving community representatives. Our 2 communication axes will build on existing networks of ANACIM and EVE for communications to the wider public

Monitoring and Evaluation: The achievement of a marked improvement in flood forecasting ability will be assessed through an M&E process. Early in the project a range of tools will be developed to baseline and track the impact over the course of the programme using a Theory of Change approach.

Measure of Success: specific indicators of impact will be developed using M&E, further measures will be (a) an increase in demand and use of flood information by key decision makers; (b) Strengthened capacity in Senegal for producing flood forecasts short time scales, (c) interest from other operational centres in the region.