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National Meteorological and Hydrological Services
Because flooding is often one of the predominant hazards in many places, most NMHSs need access to tools such as Doppler radar, which has proved to be the most valuable tool in detecting high-impact weather. Assimilating radar and satellite data into skillful18 high-resolution local area models provides the forecaster with the ability to warn on forecast rather than to warn on detection. This approach has the potential to provide longer lead times for severe forecasts from the current realizable limit of about 20 minutes for warn-on-detection approaches, thereby providing emergency managers with much earlier warnings of hazardous weather and more time to make effective decisions. The technological steps required to achieve this level of skill are challenging for many developing countries but are not impossible.
Limiting Factors in Forecasting Support for NMHSs observation networks—despite their importance for detecting high-impact weather events—has proved to be one of the biggest challenges and a limiting factor in the effectiveness of forecasting and warning systems. Gray (2012) reports that although developing countries have put much effort into strengthening land-based weather station networks for synoptic and mesoscale observations, their success is often limited. One key problem is that the focus of projects is usually on the infrastructure of the weather stations rather than on their outputs and how those outputs are used in disaster risk reduction and other services. Consequently, weather stations are often successfully installed, but staff members receive a limited amount of training in maintaining them. Ultimately, the station ceases to function, owing to lack of funding for spare parts, lack of integration into the existing observing network, or lack of trained staff members. Without the capacity to demonstrate the benefit of the new stations, funding is not provided to enhance the service. In particular, there is a paucity of data throughout Africa from synoptic stations, which inevitably results in poorer-quality numerical guidance and forecasts in those regions. Calibration of sensors used in surface observations is very important (Gray 2012), but in practice, few sensors are calibrated to internationally accepted standards. Vertical profiles of temperature and humidity from radiosondes are a high priority because these data are important for monitoring climate and for assimilating in NWP models. Operational upper-air stations are particularly sparse in Africa,19 primarily because of a lack of consumables. The WMO has estimated that, in Africa alone, there is a need for an additional 4,000–5,000 basic meteorological observations. As an ideal target, the Regional Basic Synoptic Network should have a horizontal resolution of 150 kilometers for surface observations (WMO 2011). Although several initiatives have taken up this issue, the network still has large gaps. One approach is to explore public-private partnerships, which could support new observations that would be financed and used by the private sector to meet Weather and Climate Resilience • http://dx.doi.org/10.1596/978-1-4648-0026-9