The end of the current monitoring period from January to April of 2018 covers the onset of the main growing season  for main crops (maize, sorghum, millet, and yams and cassava) throughout the West African region. This period is also the beginning of the main long rainy season lasting till the end of April to mid-July in the south, and from July to September in the semi-arid Sahel. Most of the cropped land is currently in the coastal parts areas while the northern drier parts are uncropped (this is of relevance mostly for Nigeria.)

The West African region as a whole, experienced average cumulative rainfall of 205 mm (15% above average), with positive departures recorded in Gambia (+66%), Togo (+42%), Burkina Faso (+32%), Nigeria (+25%),  Equatorial Guinea (+12%), and Ghana (+11%)  and negative departures in Gabon (-9%), Guinea (-7%) and Liberia (-4%). Precipitation is currently building up, marking the transition from the short dry season into the main rainy season starting with the southern coastal areas. Average temperature of 28.2°C (-0.9°C departure) and sunshine (RADPAR 1114 MJ/m², departure -10%) were experienced during this period. The largest departure for radiation occurred in Cote d Ivoire (-10%), Ghana (-10%), Nigeria (-11%) and Equatorial Guinea (-11%).

The fraction of cropped arable land (CALF) represents 52%  of West African arable land, predominantly in the coastal areas while the northern drier parts are uncropped (mostly in northern Nigeria. This is observed in the biomass production potential of 639 gDM m-2 (+12% over 5YA) in the MPZ. Low departures (BIOMSS departures <-20%) occur in the northern areas that are still uncropped and in coastal areas with bimodal rainfall patterns. These results are supported by the VCIx map,  an alternative index of the relative vegetation health and crop condition and a proxy to detect potential drought; the maximum VCI intensity for the MPZ was 0.64, low value area concentrated in north Nigeria.

The CropWatch indicators depict stable and coherent climatic conditions and indicate a favorable onset of the main long growing season of the MPZ.

a. Spatial distribution of rainfall profiles and departures

b. Spatial distribution of temperature profiles and departures

c. Cropped and uncropped arable land

d. Potential biomass departure from 5YA

e. Maximum VCI

e. Minimum VHI