Saturday August 12, 2017
During the past month, rainfall was persistently heavy and well above average over eastern Sudan, western Ethiopia, and northeastern South Sudan, with positive anomalies of between 100 – 300 mm during this period. This has resulted in favorable agricultural conditions, but also the potential for flooding in flood prone regions of western and eastern lowlands of Sudan. Average to above-average rainfall has extended into Yemen, southern Eritrea, northern South Sudan, Uganda, and western Kenya (Figure 1). However, rainfall was below average in Afar and parts of Tigary regions of northern Ethiopia, as well as in parts of southwestern South Sudan and northern Uganda. The eastern Horn remained seasonally sunny and dry.
Figure 1. ARC2 seasonal rainfall estimate anomalies, difference from normal (1983-2009), July 1-31, 2017 Source: NOAA/NWS/CPC
Rainfall in July continued to be above average over areas of eastern Sudan, western Ethiopia, and northeastern South Sudan, which has been favorable for cropping activities. In addition, heavier than normal rainfall is increasing the risk of flooding in many of the flood-prone areas.
Rainfall deficits have accumulated over the past 30 days in Tigray and northern Afar Regions of Ethiopia. In Kenya, a late start to the season and extended dry spells have led to reduced crop yields and poorer than usual crop production prospects.
During the next two weeks, moderate to heavy seasonal rainfall is expected to continue over western Ethiopia and eastern Sudan lowlands, with heightened risk of flooding in these regions. Meanwhile, above-average rainfall is forecast over northern Ethiopia, which could help reduce recent rainfall deficits.
Vegetation conditions remain above average in many northern areas of East Africa, according to eMODIS/NDVI (Figure 2), likely as a result of ongoing above-average rainfall in Sudan, South Sudan, and parts of western and central Ethiopia, as well as eastern Tanzania. Meanwhile, vegetation conditions remain below average in much of the eastern Horn, western and central Tanzania, southern Uganda, and eastern Equatoria in South Sudan.
Satellite-derived estimates suggest water resources are continuing to decline at surface water points in the Mandera triangle, which include the predominantly pastoral areas of eastern and southern Ethiopia, northeastern Kenya, and southern Somalia. The current dry and abnormally hotter-than-normal land-surface-temperatures are expected to continue until the Deyr/Hageya/short rains season, which normally starts in October.
Figure 2. eMODIS/NDVI anomalies (2007-2016), July 21-31, 2017 Source: USGS/FEWS NET
The following is a country-by-country update on recent seasonal progress to date:
In Ethiopia, the (June – September) seasonal rains are currently well established across the country, and during the month of July seasonal rains began on time in Afar and Tigray, though at below-average levels. Cropping conditions are generally favorable in most western areas and central areas due to good performance of seasonal rainfall since the start of the season. However, persistently well above-average rainfall over thewestern Ethiopia highlands could result in flooding during the coming weeks. These continued rains could also reduce the impact of Fall Armyworm, for which infestations have been reported in six regions of Ethiopia. Rainfall is forecast to be moderate to heavy in the coming weeks, which will likely contribute to the potential for flooding and help erase rainfall deficits in some northern areas.
Somalia remained seasonally sunny and dry, except in northern coastal areas of Somalia and areas bordering eastern Djibouti, where Karan/Xagaa seasonal rains were generally light and below average. Pasture and water resources have continued to decline in much of central and northern Somalia. However, southern regions of Somalia have benefited from localized coastal rains for the past month.
In Kenya, the shortened length of the main growing season, due in part to a delayed onset of seasonal rainfall, couple diwht long dry spells and below-average rainfall is resulting in below-average production prospects in large parts of the eastern, central, and southern Rift Valley. Key agricultural production areas areas were also affected by an erratic onset of rainfall, prolonged dry spells in June, and FAW, especially in Uasin-Gishu and parts of Trans-Nzoia counties, where maize yields are expected to be particularly poor.
In Karamoja in Uganda, rainfall during the past month has been average to above average, an improvement over below-average rainfall received early in the rainy season. This, coupled with a continuation of above-average rainfall forecast in the coming weeks, is expected to improve crop production prospects and pasture conditions. In areas of northern Uganda, particularly West Nile Region where planting was significantly delayed by almost a month, late-planted crops are currently in good condition and in maturity stages of grain filling. Harvesting and drying of first season cereals and legumes is ongoing in most bi-modal areas of central, eastern, south and western Uganda. However, the forecast widespread rainfall during the next 1-2 weeks may delay harvesting and drying activities.
In Sudan, seasonal rainfall has continued to be above average during the past few weeks, which has been favorable in most cropping areas of the country. The weekly forecasts indicate continued intensification of seasonal rainfall, with increased likelihood for flooding in flood-prone aras of eastern Sudan. However, there are localized areas in western Darfur where July rains were below average, resulting in drier-than-normal vegetation conditions. In the coming weeks, the seasonal rains are expected to intensify and may help ease the current dry conditions in parts of western Darfur.
In South Sudan, rainfall in July has generally been average to above average across the country. Widespread rains have been favorable for crop development in Greater Bahr el Ghazal and Greater Upper Nile states. According to the latest field reports, there was a slight reduction in rainfall in July compared to the previous month, over Wau and Jur River in Western Bhar el Gazal, Gogrial East, Gogrial West, and Tonj East in Warrap, and Aweil Centre County in Northern Bhar el Gazal, but the decline in rainfall was not enough to result in moisture stress on crops. Meanwhile, in Greater Equatoria, favorable rainfall since the start of July has enabled agricultural households to begin sowing. In parts of Central Equatoria (Juba County), Eastern Equatoria (Magwi and Torit counties), Jonglei (Pibor and Pochalla counties), and Western Bahr el Ghazal (Wau County), FAO and the National Ministry of Agriculture and Food Security have confirm significant infestations of Fall Armyworm.
In Yemen, second season (July to September) rainfall season started on time in July and has been above average across western, central, and parts of eastern Yemen. Vegetation conditions are currently below across many western coastal and mountainous areas of the country, with above-average vegetation conditions in parts of Ta’izz and Ibb governorates. Although, the short-and long-term rainfall forecasts are favorable for agricultural areas of the western and central highlands, production of most crops is likely to be limited due to insecurity and lack of availability and/or access to farm inputs due to ongoing conflict.
Figure 3. Week 1 GFS-Rainfall forecast (mm), valid until August 17, 2017 Source: NOAA/CPC
Moderate to heavy rainfall is expected to continue during the next two weeks across Sudan, South Suda, Uganda, northern Kenya, and western/northern Ethiopia (Figure 3). Persistent heavy rains in the Ethiopian highlands, eastern Sudan, and South Sudan, coupled with highly saturated soils in these areas, is likely to cause flooding in flood-prone areas, as is typical in August.
The expected intensification of seasonal rains over northern Uganda is expected to help gradually ease rainfall deficits that developed earlier in the season. In parts of western Kenya and central/eastern Uganda, the expected heavy rains may hamper ongoing maize harvesting and drying activities and could result in post-harvest losses, if the rains are sustained without significant dry days in coming weeks. Similarly for eastern and central Uganda, where crop harvesting is also currently on-going.
The coastal strip of Kenya and southern Somalia are also likely to receive light to moderate rains. The rest of eastern Horn is forecast to remain generally sunny and dry, as is seasonally normal.