West Africa Seasonal Monitor, June 2017
Mostly average to above average rainfall has allowed for on time to slightly early planting
In May the Intertropical Front (ITF) migrated northward faster than typical and has been located north of its climatological position, resulting in mostly above average rainfall over the region including most of the Sahelian zone.
Favorable rainfall during April and May led to timely or early planting over much of the region.
Agrometeorological conditions have generally been favorable since mid-March for normal development of planted crops over all areas where planting took place.
Given the favorable medium term forecast, sowing/planting is expected to normally continue northward into the Sudanian-Sahelian zone in June.
Update on Seasonal Progress
The ITF’s northward migration started in early March and is now located 2 or 3 degrees of latitude north of its climatological position over West Africa, with the exception of a small portion in eastern Niger where it is located slightly south of its climatological position.
The faster than normal northward migration of the ITF resulted in above-average rainfall over the Sudanian-Sahelian zone with the exception of small areas in eastern Niger, the western part of the Sahelian zone in Chad and in southeastern Chad, which experienced severe rainfall deficits (Figure 2).
This good rainfall performance over most of the region, and particularly over the Sudanian-Sahelian zone, resulted in early sowing/planting and favorable conditions for crops. In the aforementioned deficit areas, however, planting delays are possible.
Over the bi-modal zone and Sudanian-Guinean zones, where the growing season has been in progress for over 2 months, total rainfall amounts (Figure 1) from the first dekad of April to the third dekad of May are mostly average to above average (Figure 2). Areas affected by below average rainfall, with deficits ranging from light to moderate, in these two zones include eastern Liberia, southern Cote d'Ivoire, and south-central Guinea. However, deficits in these areas have been offset by a fair time distribution of rains, resulting in favorable conditions for crop development.
According to the short and medium term forecasts from NOAA/CPC, rainfall is expected to expand northward normally and will continue for the next two weeks without dry spells. This forecast calls for above average rainfall in the Central and Eastern Sahelian zone, but the bi-modal zone is expected to be moderately dry.