Gu rainfall subsides across the country, lowering the risk of flooding

Gu rainfall continued to subside across most of the country during the May 21-31 period. Little to no rainfall was reported in most of southern, central, and northeastern Somalia, though parts of the Northeast and parts of the South received light to moderate rainfall. In the Northwest, most livelihood zones continued to receive moderate to light rainfall. According to CHIRPS preliminary rainfall data, rainfall amounted to 10 millimeters (mm) or less in most regions (Figure 1). Rainfall in parts of Middle and Lower Juba, Bay, Nugaal, and Bari, as well as in the Northwest ranged from 10 to 25 mm with localized pockets receiving up to 50 mm. According to remote sensing data, rainfall deficits of 10-50 mm were observed in key crop producing regions in Middle and Lower Juba while rainfall totals in other parts of the country were 10-25 mm below the long-term mean or climatologically average (Figure 2). According to the FAO SWALIM Somalia flood update as of June 2, river water levels across Juba and Shabelle basins are declining due to the early suppression of Gu rainfall locally and in the upper river catchments in Ethiopia. Based on the rainfall forecast over the coming week, the risk of flooding is likely to decline. As of late May, OCHA reported that 412,000 people were displaced due to floods during the 2020 Gu season.

In the Northwest, moderate to light Gu rainfall was observed in most livelihood zones of Awdal, Woqooyi Galbeed, Togdheer, Sool and Sanaag regions during the May 21-31 period. However, little to no rainfall occurred in Guban Pastoral zone of Awdal and Woqooyi Galbeed; pastoral and agropastoral areas of Buhoodle of Togdheer; and localized pastoral areas of Sool and Sanaag. Exceptionally heavy rainfall in the areas surrounding Hargeisa district caused loss of lives and damaged property. Overall, pastoral rangelands are in exceptionally above-normal condition as rainfall has regenerated vegetation in areas infested by desert locust.   

In the Northeast, Gu rains were largely suppressed with little to no rainfall in most pastoral livelihood zones during the May 21-31 period. In Bari region, little to no rainfall was reported except for localized light showers observed in East Golis Pastoral and Northern Inland Pastoral Livelihood (NIP) zones. Similar trends where observed in Nugaal and northern Mudug regions, where little to no rainfall was reported apart from widespread light rainfall in NIP and Hawd Pastoral livelihood zones of Nugaal. Based on varying cumulative rainfall amounts received since the onset of the season, access to pasture and water are estimated to be below average to average in the livelihoods of Bari and average to above average in Nugaal and northern Mudug.

In central regions, all livelihoods zones of Galgaduud and southern Mudug regions experienced a dry spell during the May 21-31 period, following continuous rainfall from mid-April to mid-May. Despite the secession of rains in this period, pasture and water availability are average to above average across most livelihood zones. However, emerging swarms of locusts are reported in the eastern parts of both regions. To date, minimal damage to rangeland has occurred.   

In the South, Gu rainfall was below normal in most livelihood zones during the May 21-31 period. Little to no rainfall was observed in agropastoral, riverine, and pastoral livelihood zones of Bay, Bakool, Gedo, Hiiraan, Middle and Lower Shabelle and Middle and Lower Juba regions. Rain gauge station data and key informants suggest only localized areas of the Juba regions and Lower Shabelle received relatively light to moderate rainfall. Most key rain gauge stations in these regions recorded zero precipitation; however, stations recorded 11.8 mm in Dinsor (Bay), 9.3mm in Qansahdhere (Bay), 49 mm in Afgoye (Lower Shabelle), and 8mm in Jamame (Lower Juba). As a result of suppressed rainfall locally as well in the river catchments in the Ethiopian highlands, the Juba and Shabelle river water levels are declining to normal levels. However, station data at Buloburte and Jalalaqsi towns continue to indicate bankfull levels.

The satellite-derived eMODIS Normalized Difference Vegetation Index (NDVI) for the May 21-30 period shows positive anomalies across most of the country (Figure 3). However, deficits persist largely in rain-deficit pastoral areas of the Northeast, eastern Sanaag, and localized areas of Hiiraan, Middle and Lower Shabelle, and Middle and Lower Juba regions due to recent river and flash floods. The NOAA Climate Prediction Center’s seven-day weather forecast through June 11^th predicts the secession of rainfall in most areas of the country (Figure 4). Exceptions include localized pockets in the Northwest, most of the Shabelle valley, southern parts of Bay region, and coastal areas of the Shabelle and Juba regions, where moderate to heavy rainfall is likely over this period.

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