Global Weather Hazards Summary: July 1 - 7, 2016
Little relief to dryness expected over Guatemala and Honduras
Africa Weather Hazards
- Erratic and often below-normal rainfall since mid-May has resulted in abnormal dryness for portions of Uganda and western Kenya. This pattern has resulted in low soil moisture and poor vegetation health index values. Recent rain has improved but not eliminated dry ground conditions.
During the past 7 days, a surge in moisture and influx of rain was observed through parts of the Sahel and into the Sahara. Many areas of western Niger and Mali received at least 10 or 25mm of rain (Figure 1). The heaviest rains (>200mm) in the region were found in the western Gulf of Guinea countries. Moderate rains stretched eastward across Mali and Burkina Faso. Moderate rains were also observed over much of Nigeria and central equatorial Africa. Conversely, some local areas, such as central Liberia, central Cote D’Ivoire, and southern Ghana, largely missed out on rain. This week marked the 3rd consecutive week of above-normal rainfall for western Gulf of Guinea countries. Belownormal rainfall has been similarly consistent for parts of Ghana and Nigeria.
An analysis of cumulative rainfall anomalies during the last 30 days (Figure 2) reveals moisture surpluses that are growing quite large in some areas. Local portions of Guinea, Sierra Leone, and southern Cote D’Ivoire show positive rainfall anomalies greater than 300mm. Central Africa registers widespread rainfall surpluses as well. Between the two areas of enhanced rainfall is an area where rainfall deficits on the order of 50-100mm are prevalent.
This includes parts of Nigeria and Ghana. Ground moisture and vegetation health products do not converge on any areas for cropping concern.
Most of the region is on track for a near-normal rainfall/cropping season.
For next week, model forecasts suggest that rainfall will be enhanced again for the far western and eastern parts of the sub region. Suppression of rainfall is likely across southern Cote D’Ivoire, Ghana, Togo, and Benin. Locally heavy rain (>100mm) is possible over parts of the western Gulf of Guinea region where soils are already saturated from repeated weeks of above-average rainfall, raising slightly the risk of flooding.