October to December 2017 Deyr rainfall below average in most regions of Somalia

October to December 2017 Deyr rainfall started two to three weeks later than usual in central and southern areas of the country and, as a result, rainfall totals in October were significantly below average. In areas that did receive rainfall, distribution was poor across both space and time. The majority of Deyr rainfall in southern and central regions occurred in early November and rainfall totals were much greater than normal for this time period. Rainfall in late November and December was minimal. Given that rainfall was only received in earnest between late October and early-November, the Deyr season was shorter than usual. In central regions, isolated areas received above-average rainfall, though rainfall was below average in most areas, totaling only 25 to 50 millimeters (mm), according to satellite-derived rainfall estimates by RFE (Figure 1). This is roughly 50 to 75 percent of average. In the South, most areas received between 100 and 200 mm of rainfall, between 25 and 75 mm below the short-term mean (STM) (Figure 2). However, rainfall totals were above average in regions along the border with Ethiopia. In the North, most rainfall was received in September and October, and total cumulative rainfall was 25 mm or less, compared to 30 to 50 mm in a normal year. Rainfall according to preliminary Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) show broadly similar trends in amount and location of rains, with most of the country receiving less than 75 percent of normal rainfall. 

In the Northwest, Deyr rainfall started early and most rainfall was received between September and October. Little to no rainfall was received in November and December. Total seasonal rainfall was below average in most areas, and rainfall deficits ranged between 10 and 50 mm. Rainfall deficits were higher in Guban Pastoral livelihood zone and Togdheer Agropastoral livelihood zone, which received little to no rainfall. Conversely, Hawd and Golis Pastoral livelihood zones of Togdheer and Sool received relatively greater rainfall, but amounts were still less than the STM.

In the Northeast, Deyr rainfall started in late September/early October in most areas, though little to no rainfall was received in November and December. The exceptions to this are Coastal Deeh Pastoral livelihood zone of Bandarbeyla and Hawd Pastoral livelihood zone of Galkacyo, where some rainfall was received in late October and towards the end of the season. Overall, most livelihood zones received less than 10 mm of rainfall, though some received between 10 and 50 mm. 

In central regions, Deyr rainfall started on time, though rainfall totals were below average during the first month of the season. In early November, average to above average rainfall with normal distribution was received in all areas except Hobyo District, and in late November, near average rainfall was received in most areas of Galgaduud and pockets of southern Mudug. No rainfall was reported in December. Overall, rainfall was roughly 25 to 50 mm below average.

In the South, minimal rainfall was received in early and mid-October, though most areas received above average rainfall between late October and mid-November. Only minimal amounts of rainfall were received in December. According to satellite-derived rainfall estimates, most areas received 50 to 100 mm, while most of Bay and parts of Hiiraan, Bakool, Gedo and Lower and Middle Juba received 150 to 250 mm. Relative to the STM, most areas experienced total seasonal rainfall deficits between 50 and 100 mm, though rainfall was average to above average in some areas along the border with Ethiopia. However, even in areas where rainfall was above average, rainfall was poorly distributed across the season. No major flooding was reported from the Shabelle and Juba Rivers during the Deyr season, though intentional flooding occurred in some riverine areas of Juba where farmers opened river barrages for irrigated cultivation.  

The satellite-drived eMODIS Normalized Difference Vegetation Index (NDVI) Anomaly shows overall below-average vegetation conditions in southern regions, which supports expectations for overall below-average 2017/18 Deyr production (Figure 3). The Climate Prediction Center’s 7-day rainfall forecast indicates no rainfall between January 4 and 10, signaling the end of Deyr season (Figure 4).  

For more rain gauge data, please, contact So-Hydro@fao.org or visit www.faoswalim.org.

FEWS NET publishes a Seasonal Monitor for Somalia every 10 days (dekad) through the end of the October to December Deyr rainy season. The purpose of this document is to provide updated information on the progress of the Deyr season to facilitate contingency and response planning. This Somalia Seasonal Monitor is a summary of Deyr 2017 seasonal performance and the final Seasonal Monitor of the season. This Monitor is produced in collaboration with the Food Security and Nutrition Analysis Unit, U.S. Geological  Survey (USGS), and the Somali Water and Land Information System (SWALIM).