Rainfall induced by the remnants of ex-Tropical Cyclone Japhet and other rainfall systems is still being experienced over Zimbabwe and Mozambique, but is expected to diminish over the next couple of days. The SADC Drought Monitoring Center (DMC) recently released a Tropical Cyclone Advisory stating that by Wednesday, the rainfall activity related to ex-Tropical Cyclone Japhet is expected to diminish significantly across much of central and southern Mozambique, and Zimbabwe. These were the main areas affected by Japhet-induced weather over the past 2 weeks, resulting in the loss of at least 19 lives, and significant damage to infrastructure. The DMC however noted that atmospheric conditions over Zimbabwe and Mozambique are still favourable for convective rainfall to occur especially after intervals of sunshine. Over the next few days, rainfall activity is generally expected to shift northwards to the areas over "extreme northern Mozambique, southern Tanzania, Malawi, Zambia, southern DRC and Angola". The forecast rainfall from 10 to 13 March over southern Africa is shown in Figure 1.
Meanwhile, river levels have increased significantly in the Save catchment over the last few days. Although the main weather activity related to the cyclone appears to be diminishing, the rivers in the main affected areas are still at high levels. For example, river levels at the Save Gorge rose significantly on Friday 7 March, and are still maintaining a high level. The FEWS NET SFM hydrological model, operated at the USGS, is indicating that many rivers in the affected areas, as well as other rivers in central Malawi, northern Mozambique, and northern Zimbabwe, may be at risk of flooding (Figure 2). There is therefore a need for people to stay alert, particularly in downstream areas, where extensive flooding may not have taken place, as the flooding or high river levels experienced upstream may take some time before they are experienced downstream.
The significant Weather Developments Bulletin is intended to provide timely highlights of developing weather patterns that might pose a threat to human lives and property. While efforts have been made to ensure accuracy of this report, country specific requirements should be addressed to the National Meteorological Services. The RRSU and FEWSNET produce a Situational Regional Floodwatch during the rainy season.
Acknowledgements: The information in this bulletin is derived from an analysis of issuances by the JTWC, La Reunion Tropical Cyclone Centre, and SADC DMC. An analysis of Meteosat satellite imagery, NOAA satellite-derived rainfall estimates, AFWA rainfall forecast models, USGS/FEWS NET water balance and hydrological streamflow models, ground reports, and any other available information is incorporated to estimate ground impacts. USGS/FEWS NET also provides direct input.
The SADC Remote Sensing Unit, P.O.
Box 4046, Harare, Zimbabwe.