ALERT | Rift Valley fever (RVF) | Seasonal Outlooks | Southern African Region
Rift Valley fever (RVF) | Seasonal Outlooks | Southern African Region
Attached is the seasonal outlook report with notable observations below:
Page 1. The Ocean Nino Index is currently at +1.1 (The ONI is the rolling 3-month average temperature anomaly—difference from average—in the surface waters of the east-central tropical Pacific, near the International Dateline). The ONI indicates that El Niño conditions are already present (Index values of +0.5 or higher indicate El Niño; values of -0.5 or lower indicate La Niña). Forecasts of the ONI project that we are going to max out at +2.0 during the period November – February 2023/2024, though this is likely to be higher.
Page 2 and Page 3. Consequences are shown in forecasted continental rainfall anomalies for SON2023 with Eastern Africa expected to receive an excess of 40mm or more while Southern Africa is expected to have a deficit of between 10 and 35mm, with the center of the deficit over Free State and Lesotho (This is the so-called continental dipole pattern)
Page 4. The dry/deficit pattern will be enhanced and expanded over the Southern Africa region during OND 2023 except in Mozambique and Angola.
Implications : If these patterns hold as expected, we are going to have dramatic reduction in flood water mosquito collections and consequences for other sectors including agricultural production.