Outlook for October-November-December 2023 “Short Rains” Season
Reference is made to the Kenya Meteorological Department (KMD) Seasonal Forecast for the Period October – November – December 2023.
Summary of the Climate Outlook for the October-November-December (OND) 2023 “Short Rains” season
The Climate Outlook for the October-November-December (OND) 2023 “Short Rains” season indicates that the whole country is likely to experience enhanced rainfall with higher probabilities over the eastern zone. This will be driven by warmer than average Sea Surface Temperatures (SSTs) over the central and eastern equatorial Pacific Ocean, indicating the presence of El Niño conditions.
According to most of the global climate models, El Niño conditions are likely to persist throughout the OND season. Additionally, the warmer than average SSTs in the western equatorial Indian Ocean (adjacent to the East African coastline), coupled with cooler than average SSTs over the eastern equatorial Indian Ocean (adjacent to Australia) constitutes a positive Indian Ocean Dipole (IOD) that is favorable for enhanced rainfall over most of East Africa. Throughout the season, it is likely that most areas will have a relatively fair to good distribution of rainfall in both time and space. Occasional storms are likely to occur over several parts of the country during the season. The temperature forecast suggests that for the larger part of the country, the season is likely to be warmer than average, except in isolated areas over the northeastern zone where temperatures are expected to be lower than average.
Demystification of the El Nino phenomenon
El Niño and La Niña events (collectively referred to as the El Niño–Southern Oscillation or ENSO) are driven by changes in Sea Surface Temperatures (SST) over the equatorial Pacific Ocean. During El Niño, SST in the central and eastern Pacific Ocean become warmer than average, while La Niña is characterized by cooler than average sea surface temperatures in the same regions. El Niño is often associated with heavy rains and floods during the OND season especially in East Africa.
It is important to note that El Niño itself is not rain, but rather an effect that can impact weather patterns and lead to heavier-than-normal rainfall in East Africa. While heavy rains are commonly experienced during El Niño events, it is also notable that these effects are typically most significant during the ONDJ months. It should also be understood that El Niño is not necessarily a direct cause of heavy rainfall. While it can impact weather patterns and result in heavier-than-normal rainfall, the effects of El Niño can vary significantly between events. For instance, the 1987 OND season was an El Niño event that did not result in heavy rainfall over the country. Additionally, in 2015, the El Niño index was higher than that of 1997 but the country did not experience as much rainfall as it did in 1997.
Major Impacts
While enhanced rainfall is likely to alleviate the drought situation, and offer an opportunity for water harvesting, among other positive impacts, the following negative impacts are likely during the OND 2023, inter alia:
- Floods and flash floods are likely over several parts of the country especially over the Coast, Southeastern lowlands, Lake Victoria Basin, parts of the Central and South Rift Valley, Northeast and Northwestern parts of the country and urban centers with poor drainage systems. This could lead to destruction of property, loss of lives and displacement of people.
- Landslides and mudslides are likely over some parts of the Highlands West and East of the Rift Valley, Central and South Rift Valley and the Southeastern lowland
- Lightning strikes are highly probable over the western parts of the country especially in Kisii, Kisumu, Nandi, Kakamega and Bungoma (Mt. Elgon areas) counties.
- Heavy rainfall may enhance rising of water levels in rivers, lakes and dams, as well as lake back flows
- There may be re-emergence of desert locusts over some parts of the country
- Infrastructural failures (building collapse, bridge failures cutting off major roads, damage to key installations
- Disruption of social economic activities such as education, agriculture and supply chain
- Power outages, causing disruption of key economic activities, as well compromising security, especially in the usually lit build up areas
Disaster Risk Management (DRM) Advisory
DRM stakeholders (at national, county and local/community levels) are encouraged to enhance awareness creation and capacity building on disaster preparedness for effective response.
The public is advised to AVOID crossing areas where water levels would be above their knees when walking, or above the tyres if driving/cycling to mitigate against DROWINING.
County Governments are also encouraged to clear drainages and ensure the drainage systems are well done to avert artificial flooding, especially in the urban areas. Respective stakeholders are also encouraged to ensure water passages, alleys, channels and dried up rivers are cleared of debris, to avoid flooding in the event of sudden storms during the season.
DRM Stakeholders, as well as humanitarian organizations, are advised to enhance the measures that are already being implemented to avert the loss of lives, livelihoods, and livestock.
Generally, we are all urged to keep track of other KMD forecast products (monthly, weekly, and daily forecasts and advisories ) for early warning information, and undertake early actions to ensure maximum protection of life and property during the OND 2023 “Short Rains” Season.
NDMU will continue to undertake stakeholders’ sensitizations/awareness creation and capacity building on disaster preparedness for effective response and building back better in recovery, through an all-hazards approach, and whole of society/community approach. You may reach us through our X Handle @NDMU_Kenya or EMAIL: info.ndmu@disastermanagement.go.ke