NOAA’s African Desk: Twenty Years of Developing Capacity in Weather and Climate Forecasting in Africa (2024)

NOAA’s African Desk, established in 1994, provides decision support services and contributes to the development of capacity in weather and climate forecasting through knowledge and technology transfer.

Drought is one of the leading causes of death in Africa because of its impact on access to sanitary water and food. This challenge has mobilized the international community to develop famine early warning systems (FEWS) to bring safe food and water to populations in need. Over the past several decades, much attention has focused on advance risk planning in agriculture and water and, more recently, on health. These initiatives require updates of weather and climate outlooks. This paper describes the active role of NOAA’s African Desk in FEWS and in enhancing the capacity of African institutions to improve forecasts. The African Desk was established in 1994 to provide services to U.S. agencies and African institutions. Emphasis is on the operational products across all time scales from weather to climate forecasts in support of humanitarian relief programs. Tools to provide access to real-time weather and climate information to the public are described. These include the downscaling of the U.S. National Multimodel Ensemble (NMME) to improve seasonal forecasts. The subseasonal time scale has emerged as extremely important to many socioeconomic sectors. Drawing from advances in numerical models, operational subseasonal forecasts are included in the African Desk product suite. These capabilities along with forecast skill assessment, verifications, and regional hazards outlooks for food security are discussed. Finally, the African Desk residency training program, an effort aimed at enhancing the capacity of African institutions to improve forecasts, and supported by this seamless approach to operational forecasting, is described.

Global climate fluctuations and their impacts on economic development have been a worldwide concern over the past several decades. The problem is even more acute in Africa, where alternating severe droughts and floods have been persistent causes of severe economic hardships. Recurrent and severe droughts along the Sahel band from the eastern Atlantic coast of West Africa to Ethiopia and Somalia, which started in the late 1960s (Lamb 1978; Nicholson 1980) and extending into the 1970s and the 1980s, caused demand for water for human and agricultural use to exceed reliable supply. African National Meteorological Services (NMSs) were extremely challenged to deliver timely and reliable climate information and services to respond to the needs of governments and the public for informed decision making.

The Comité Inter-Etat de Lutte Contre la Sécheresse au Sahel (CILCSS) headquartered in Burkina Faso and its technical body the Centre d’Agriculture, d’Hydrologie et de Météorologie (AgrHymet) located in Niger were formed in partnership between the Sahel countries and international donors to address the challenges associated with the water deficits.

The U.S. Agency for International Development (USAID) started a famine early warning systems (FEWS) project in the mid-1980s and coordinated activities with the Centre AgrHyMet. The objective was to provide the United States and Sahel countries with timely food security information to enhance decision support tools for humanitarian relief planning and response in the areas most affected by the droughts. The USAID FEWS project recognized quickly the importance of weather and climate as a key factor in agricultural production and river flow. The National Oceanic and Atmospheric Administration (NOAA)’s Climate Prediction Center (CPC) began to provide USAID FEWS with real-time gauge-based 10-day weather summaries to enable operational monitoring of crop conditions. However, given the difficulty to access rain gauge measurements from Africa, CPC also began to provide USAID FEWS with access to real-time satellite rainfall estimates to improve the weather summaries and to enable effective monitoring of drought conditions.

While the Sahel water shortages continued to increase, the severe droughts in southern Africa during the 1991/92 El Niño event (Cane et al. 1994) and persistent flooding resulting from enhanced rainfall activity in equatorial Africa during warm El Niño–Southern Oscillation (ENSO) events (Ropelewski and Halpert 1987; Ogallo et al. 1988) further demonstrated the need for improved research, prediction, and monitoring of the African climate system. The African Centre of Meteorological Applications for Development (ACMAD) was established in 1987 by the Conference of Ministers of the African Union (AU). Then the Drought Monitoring Centre Nairobi in Kenya and its subcenter in Harare Zimbabwe were created in 1989 by countries in eastern and southern Africa. Both centers have since evolved to become the Intergovernmental Authority on Development (IGAD) Climate Predictions and Applications Centre (ICPAC) in Nairobi, Kenya, and the Southern African Development Community (SADC) Climate Services Centre (SCSC) in Gaborone, Botswana, respectively. These continental- and regional-scale initiatives were prompted by the numerous challenges faced by African governments to cope with devastating weather related disasters. The Earth Summit in Rio de Janeiro in 1992 called for a mobilization of the international community for sustainable development especially in Africa. USAID FEWS also expanded its mission to eastern and southern Africa.

Recognizing that to assist African institutions meet the challenges of extreme weather events requires access to timely weather and climate information, the National Weather Service (NWS) established the African Desk in 1994 at CPC of the National Centers for Environmental Prediction (NCEP) as part of the U.S. contribution to the World Meteorological Organization (WMO) Voluntary Cooperation Program (VCP). The VCP is funded by the State Department and managed by NWS. The goal of the VCP is to foster collaboration between WMO member countries and to develop capacity in weather and climate wherever needed through transfer of technology and expertise. Hence, the African Desk from the outset focused on the development and the delivery of climate products that meet the requirements for operational monitoring at NMSs and on professional development training as part of the NCEP International Training Desks (ITD). The NCEP ITD includes the South American Desk and the Caribbean Desk established at the Weather Prediction Center (WPC) in 1989 and 1993, respectively. These two desks specialize in operational weather forecasting for South America and the Caribbean.

The African Desk initially focused on climate monitoring and forecasting. A Weather Desk was added in 2006 in support of the WMO Severe Weather Forecasting Demonstration Project (SWFDP) for southern Africa. The expansion included training in weather forecasting and the development of operational weather forecasting products that meet the requirements of NMSs in Africa. The African Desk also further expanded as projects to support the mission of USAID Office of Foreign Disaster Assistance (OFDA) were implemented. These include the provision of 1) real-time tropical cyclone alerts and extremely heavy rainfall forecasts for the Indian Ocean basin drawing from forecasts from the Joint Typhoon Warning Center (JTWC) and NCEP; 2) satellite rainfall estimates for South Asia in support of flash flood forecasting guidance along the Mekong River, working with both the International Center of Integrated Mountain Development (ICIMOD) in Nepal and the Mekong River Commission (MRC) in Cambodia; and 3) a postdoctoral appointment at CPC for young scientists from developing countries. The USAID FEWS became FEWS Network (FEWSNET) and expanded its mission during this time to include Afghanistan, Central America, and Hispaniola. The African Desk was then merged with the FEWSNET unit at CPC and began to provide FEWSNET with regional hazards outlooks for food security in all the regions of interest to FEWSNET.

The residency training program of the African Desk was also further expanded with the establishment of the CPC Monsoon Desk in 2010 to form with the African Desk and other international activities—what is now known as the CPC International Desks (ID). Thus, the core mission of the CPC ID is to provide access to NCEP operational global climate monitoring and forecasting and to develop capacity in the use and interpretation of such products through both a residency and offsite training programs.

In the following, the function of the desk is presented. Then access to real-time NCEP products to support operational forecasting and climate monitoring is discussed. An example of the various expert assessment products with a focus on the regional hazards outlooks for food security is presented. Finally, the professional development training program is described, followed by a summary.

THE FUNCTIONS OF THE AFRICAN DESK.

NCEP is one of very few global weather and climate centers in the world that provide unrestricted access to a suite of weather and climate information from short range forecasts to seasonal and interannual climate predictions globally. These forecasts are accompanied by a set of real-time monitoring products featuring the state of the global climate providing the most up-to-date information on ENSO and the state of the global ocean, the global monsoon, and drought information. As stated earlier, the African Desk was established on one hand to provide NMSs in Africa with timely access to weather and climate information to support decision making and on the other hand to recognize the emphasis on weather and climate within the U.S. government humanitarian assistance programs such as USAID. In essence, the African Desk is the NCEP focal point for real-time dissemination of operational African weather and climate data and products, which are integrated into the process of systematically updating food security outlooks for informed decisions in foreign aid such as food and water supply and assistance in population displacements. The African Desk operations also feed directly into NMSs monitoring and forecasting operations. The primary functions of the desk are to continuously monitor weather and climate patterns in Africa and to disseminate these in the form of bulletins or briefings via the CPC website and through e-mail distribution lists. Specific operational weather and climate products are derived from NCEP observational data and model outputs and seamless forecasts from short range weather to seasonal climate outlooks are issued. These serve as guidance to NMSs operations. The sources for observational data include the NCEP reanalysis (Kalnay et al. 1996), the CPC global land precipitation data (PREC/L) (Chen et al. 2002), the CPC African rainfall climatology version 2 (ARC2) (Novella and Thiaw 2013), the extended reconstructed sea surface temperature version 3 (ERSSTv3b) (Smith et al. 2008), and the National Aeronautic and Space Administration (NASA) Tropical Rainfall Measuring Mission (TRMM) 3B42v7 (Huffman et al. 2007). Anomalous weather and climate are identified and the information communicated to partner agencies. Land surface information is gathered from partner agencies within FEWSNET and integrated with up-to-date weather and climate data to provide regional hazards outlooks. This information provides initial qualitative crop impact assessments that can feed into food security outlooks. In addition, NCEP data are staged and reformatted in a way that NMSs can access and use them. Finally, hands-on training in operational monitoring and forecasting of weather and climate, and the assessment of impacts, are delivered to NMSs staff.

PROVIDING ACCESS TO NCEP PRODUCTS.

The African Desk expanded its mission tremendously over the years to provide access to NCEP data and products globally. Products are made available primarily through a website displayed in Fig. 1. This page, which initially focused on Africa, has now evolved into the CPC ID website. The links at the top of the page provide access to the NCEP Climate Forecast System version 2 (CFSv2) (Saha et al. 2014) and the U.S. NMME (Kirtman et al. 2014) in both global and regionalized formats. Below these links is the main weather website and also home to bulletins and summaries of weather and climate forecasts and evolving conditions for Africa and different regions of the world. In both the climate and weather web pages, the globe is divided into ocean basins and continental regions. The continental regions include Africa, Central America, the Caribbean, the Maritime Continent, Central Asia, East Asia, South Asia, and South America. The weather page features 1) the expert assessment bulletins, forecasts, and summaries; 2) weather and subseasonal forecasts derived from the NCEP Numerical Weather Prediction (NWP) over various regions in Africa and over all of Africa for a wider view; 3) surface observations, analyses, and monitoring products, including SST; and 4) satellite derived rainfall estimates.

NCEP model guidance is staged for the globe as well as continental and regional domains, including East Africa, northern Africa, southern Africa, and West Africa. Both deterministic and ensemble guidance products are displayed. The ensemble page features products critical to forecasting severe weather events. Graphical displays include probability of exceedance of parameters such as precipitation and winds for various threshold values. For precipitation, the range is from 1 mm to more than 100 mm.

The climate forecasting page features CFSv2 and the U.S. NMME model guidance, including SST predictions expressed in the form of anomalies, standardized anomalies, and skill-masked standardized anomalies. Skill mask is applied such that only anomalies at grid points where the correlation coefficient between the model SST forecasts and the observed SST (ERSSTv3b) is equal or greater than 0.3 are displayed. This is similar for the precipitation and air temperature forecasts, which also include maps of departures from climatological probabilities of the three equiprobable categories of above-, near-, and below-average rainfall (Thiaw et al. 1999). Figure 2 shows seasonal rainfall guidance maps for Africa expressed as indicated above. An examination of the maps reinforces the fact that there clearly is a need to express seasonal forecasts in probabilistic form to convey uncertainty in the forecasts and also to remove signal from random forecasts. Deterministic forecasts expressed in terms of standardized anomalies (Fig. 2a) show a very wet Sahel for July–September 2014, with 1–8 May initial conditions. However, the probability forecasts (Fig. 2b) show a much reduced signal in this region, with only a slight tilt in the odds to favor above-average rainfall in the Sahel. The probability forecasts convey the uncertainty in the forecasts and allow for more informed decision based on the forecasts.

This real-time weather and climate information accessible through the website can be of tremendous benefit not only to NMSs and USAID programs but also to the public globally and especially the education sector providing the current state of the climate and its evolution at any given time.

EXPERT ASSESSMENT PRODUCTS.

The various bulletins produced in the African Desk include seasonal rainfall outlooks, subseasonal outlooks, weather forecasts, and regional hazards outlooks that enable decision making in food security. Because of space limitation for this article, the latter is discussed here. The hazards outlooks bulletin for food security is prepared weekly in collaboration with FEWSNET partners, including the U.S. Geological Survey (USGS), NASA, USAID, and Chemonix. The bulletin features both long-term (past conditions throughout the season) monitoring of the climate system and outlooks into the near future about one week to a season. The objective is to provide targeted forecasts for areas that are vulnerable to droughts or flooding that might result in adverse impact on crops or pastures. Hence, the hazards outlooks are based on a wide range of products, including rain gauge data and satellite rainfall estimates, rainfall and surface temperature forecasts up to 16 days, and subseasonal and seasonal climate forecasts. Other inputs to the hazards outlooks include USGS’s river flow forecasts and water requirement satisfaction index (WRSI) for crops and rangelands (Senay et al. 2011), NASA’s normalized difference vegetation index (NDVI) (Fung et al. 1987), NOAA’s vegetation health index (VHI) (Kogan 2002), and field observations. Figure 3 shows a schematic of the regional hazards outlooks process designed as a loop that begins with the identification of areas that exhibit consistent rainfall deficits or frequent flooding through routine in-depth monitoring of the climate system. These areas are often faced with a high risk of food insecurity. Then model guidance tools are used to examine both short range and extended range forecasts. The reliability of these forecasts is qualitatively assessed by looking at consistency both within each model and between different models. Then, based on current conditions and forecasts, a geographical information system (GIS) software is employed to draw polygons on a map to highlight areas at risk for food security. The preliminary hazards outlook bulletin is distributed to partners within FEWSNET including the field representatives who have expert knowledge of conditions on the ground. Then a teleconference takes place for a live discussion of current weather and climate conditions and the preliminary hazards outlooks. The feedback received allows for the finalization of the hazards outlooks. An example of a hazard outlook valid for 2–8 January 2014 is displayed in Fig. 4. Polygon shapes are numbered and show areas of concern for flooding or drought. The numbering allows for the long-term monitoring of the conditions in the areas of interest. The color shades determine the nature and severity of the hazards. In the example shown in the figure, delayed onset to the start of the rainfall season and poor temporal distribution of the rains since the beginning of the season resulted in drought in polygon area 1 encompassing much of northeastern Kenya. Developing dryness that may have adverse impacts on crops is highlighted in polygon areas 2, 3, and 4. In contrast, four consecutive weeks of above-average rains caused flooding to persist along the Caprivi Strip in northeastern Namibia and neighboring areas (polygon area 5), while the development of a tropical wave disturbance was expected to result in flooding over west central Madagascar. The hazards outlooks are disseminated through the website and an e-mail distribution list. FEWSNET uses the information together with current climate forecasts and trends and other food security indicators to issue monthly food security outlooks. Finally, this information is provided to USAID for informed decision in humanitarian response planning based on the level of food security threats.

PROFESSIONAL DEVELOPMENT TRAINING PROGRAM.

SUMMARY.

For two decades NOAA has been providing support to African NMSs to develop capacity in weather and climate forecasting through a residency training program and the delivery of products required for operational monitoring and forecasting of weather and climate. NOAA has also been working with sister agencies with specific interest in Africa and the developing world to support decision making in areas that are challenged by natural disasters such as droughts, floods, tropical cyclones, etc., and considered economically vulnerable because of shortage of food or drinking water. NWS established the African Desk at CPC in March 1994 as a part of the NCEP ITD. It became operational and hosted its first trainee from Kenya in March 1995. The desk focused initially on climate monitoring and forecasting. Then a weather desk was established in 2006 to provide support to the WMO SWFDP through training in weather forecasting and the development of products required for severe weather forecasting. One hundred thirty six professional meteorologists from 38 countries in Africa have since been trained in the African Desk. Four former trainees moved up in the chain of command to become WMO Permanent Representatives (PRs) of their respective countries. Dozens moved up to leadership positions. In 2010, the activities of the African Desk were further expanded with the establishment of the Monsoon Desk in 2010. The two desks, combined with the international projects in support of the U.S. government humanitarian mission around the world, now form the CPC ID.

Despite the success of the NCEP residency training, the demand for training in operational climate monitoring and forecasting remains far greater than current NCEP capacity to meet it. Hence, the NOAA/USAID climate training workshop series serve to fill the gap by providing professionals from developing and emerging countries around the world an opportunity to improve their understanding of the climate system and enhance their forecasting skills to improve climate services. The training programs also provide an excellent opportunity to use NCEP and U.S. NMME model data and to evaluate the performance of the models especially in the tropics. Through this process, NMSs can develop effective weather and climate monitoring tools that enable decision making.

Finally, one of the key missions of the CPC ID is to provide domestic and international agencies with access to real-time NCEP operational weather and climate forecasts for any given region of the world. A website has been created and maintained for this purpose. The CPC ID also provides support to many domestic and international programs, including the USAID’s FEWSNET and Disaster Risk Reduction (DRR) Program, RCOFs, and more recently the World Health Organization (WHO) climate and health initiative.