A recent advisory released by the SADC Drought Monitoring Center stated that the activity of ex-Tropical cyclone Japhet, still classified as a depression, is likely to continue into at least early next week. The tropical depression is expected to affect the South Africa-Zimbabwe, and Zimbabwe-Mozambique border areas during the next 5 days. Significant rainfall is anticipated over southern and central Mozambique, northern South Africa, and southern and eastern Zimbabwe. Thunderstorm activity and strong winds are expected over the Mozambique, South Africa, and Zimbabwe borders. The system, currently (as at 0600GMT, 5 March) lying over southern Zimbabwe, is anticipated to initially track south-westwards, before curving south-eastwards, as the remnants of the system shift from Zimbabwe to Mozambique. The advisory also stated that during the period over the weekend and into the beginning of next week, the main activity of the system is expected to shift northwards over north-eastern Zimbabwe and central Mozambique areas.
HEAVY RAINS OVER THE LIMPOPO RIVER BASIN; SAVE RIVER DECLINING
In the last few days, significant heavy rains have fallen on the Zimbabwe side of the Limpopo River basin due to the effects of Japhet (Figure 2). Due to the extremely dry conditions that have been prevailing in this area throughout the season however (Figure 1), it is expected that this rainfall can only be beneficial =13 very excessive rains will be required to cause flooding in these areas. Meanwhile, it was noted in a previous issue of the Significant Weather Developments bulletin that the Save River was likely to reach its highest river levels on Thursday 6 March. Further analysis of river gauge observations and hydrological model runs by the USGS group suggest that river levels in the Save Gorge have already reached a maximum, and are now on a decline.
LAKE MUTIRIKWI SPILLS
Lake Mutirikwi, the biggest inland dam in Zimbabwe, spilled recently as a result of the recent heavy rains associated with ex-Tropical Cyclone Japhet (Figure 2). Mutirikwi River also burst its banks due to the high rains. News reports indicate that on 5 March, 12 families staying on an island on the river, about 80 km downstream of the Lake, were marooned when the river burst its banks. The Civil Protection Unit responded quickly to this incident, sending off teams to rescue the families. Mutirikwi River is one of the tributaries to the Runde River, which in turn feeds into the Save River. A flood wave on the Mutirikwi is likely to be felt further downstream on the Runde, and later on the Save River.
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.