Global Weather Hazards Summary: February 22 - 28, 2019
Drought strengthens in parts of Angola and Namibia
Significantly below average rainfall since October has caused significant dryness in southern Africa. Dry spells continue in Namibia and Angola.
Below-average rainfall since November has caused drought in South Africa, though there has been recent moisture improvement.
Heavy rainfall in Mozambique, Zimbabwe and Botswana This past week above-average rainfall with weekly accumulations exceeding 100mm were registered over central and southern Mozambique, Zimbabwe, Zambia, and northern and eastern Botswana (Figure 1). More favorable rainfall amounts of more than 50mm were received in Zambia, Malawi, South Africa, the Caprivi Strip region of Namibia, and Madagascar. Meanwhile, below- average accumulations were observed over parts of Namibia, Angola, northern Mozambique, Tanzania, and Madagascar. Areas in southwestern Angola, western Namibia and eastern Tanzania received no rainfall at all.
Zambia, northern Mozambique, Malawi, and northern Tanzania have experienced several periods of heavy rainfall over the past 30 days, with moisture surpluses in southeast Mozambique, northern Madagascar, and South Africa (Figure 2). Wetter than average conditions have caused flooding in Madagascar, Zimbabwe, and Malawi. In South Africa, increased rainfall over the past 3 weeks has allowed for short term recovery, though deficits persist over the 90-day period for some areas, especially in the west.
Meanwhile, extremely poor percent of normal precipitation values over southern Angola, Namibia, western South Africa, and western Botswana persist (Figure 2). Many parts of southern Angola, northern Namibia, western Zambia, northern Zimbabwe, and western South Africa, experiencing dryness over the past month, have also registered below-average precipitation amounts since early November, with near-record low precipitation amounts for the last 90 days. Periods of 6-8 consecutive weeks of below-normal rainfall are common in these areas, though with little moisture increase during the first half of February, drought conditions have strengthened.
In Madagascar, a poor start to the rainy season at the end of 2018 was followed by a wet period in January with good moisture recovery. The weather pattern has returned to several weeks of below-average rainfall in southern and central areas, now registering negative 30 and 90-day anomalies.
Next week, monsoon convergence is likely to move north and bring increased rainfall to areas that have received good moisture since January. Heavy rainfall amounts over 100mm are likely in northern Mozambique, Malawi, eastern Zambia, and southern DRC. Below- average rainfall is forecast for Namibia, Botswana, Zimbabwe, and western South Africa.