Development of a Spatial Synoptic Classification Scheme for East Africa with a Focus on Kenya

Despite the wide range of applications of the Spatial Synoptic Classification (SSC), its expansion and utility in the tropics remains limited. This research utilized the fifth generation of European ReAnalysis (ERA5) data to develop an SSC scheme tailored for East Africa with a focus on Kenya. The SSC method classifies weather into seven types: Dry Polar (DP), Dry Moderate (DM), Dry Tropical (DT), Moist Polar (MP), Moist Moderate (MM), Moist Tropical (MT), and Transitional (TR). Frequency and trend analysis between 1959 and 2022 show that the MT and DM weather types are the dominant types in Kenya. The DM type is dominant in the December–February (DJF) dry season while the MT type is common from April to September. We find statistically significant decreasing trends in the DM, MP, and MM weather types and increasing trends in the DT and MT weather types. The results suggest that, generally, the number of days with cool and moderate conditions in Kenya is decreasing, while the number of days with warmer conditions is increasing. This research indicates the potential for the SSC to be utilized in different applications in East Africa including investigating heat vulnerability, as increasing temperatures could be a significant risk factor to human health.