South African Weather Service
16 February 2017: 11:00
Tropical cyclone Dineo made landfall near Inhambane, southern Mozambique between 8pm and midnight last night, Wednesday, 15 February. Strong winds, exceeding 100km/hr as well as torrential rainfall and very rough seas were most likely the main weather-related impacts.
While no direct measurements of rainfall are available in the immediate area of landfall, given the extreme nature of the weather, satellite-derived estimates of overnight rainfall strongly suggest that at least 100 to 200mm of rain (or even more) occurred overnight, along the coast and adjacent interior, between Inharrime in the south and Vilanculos in the north. Confidence in the aforementioned rainfall estimate is further supported by overnight rainfall measurements at Vilanculos (110mm) as well as Maputo (33mm).
By 8am this morning (refer Figure 1), ex-Dineo has moved progressively inland, and now classified as a tropical depression. Note that the name convention “ex-Dineo” denotes that the formerly marine storm system is now located over land. The central core of the system is close to Chigubo and the Banhine National Park in southern Mozambique at the current time, although the vortex of ex-Dineo is becoming more indistinct as the system weakens. Notwithstanding this weakening trend, the system will still pose a great risk for the next 36 to 48 hours, particularly in terms of further exceptionally heavy rainfall and resultant flooding.
While the greatest threat today will no doubt be over the entire southern Mozambican region, from Beira southwards, there is also an increasing risk of heavy showers and thunderstorms over the lowveld and escarpment regions of Mpumalanga and Limpopo today, especially towards evening and overnight, when very heavy rain, of the order of 100 to 200mm can be expected over the eastern half of Limpopo province, continuing into tomorrow, Friday, 17 February. In the latter half of Friday, patches of heavy rain may also occur over the western parts of Limpopo province as well as northern Botswana, as the remnants of the low track progressively further westwards over the African subcontinent. By Saturday, patches of heavy rain occurrence could even persist over the northern parts of Namibia and Botswana respectively.
Naturally, the low-lying, predominantly flat terrain of southern Mozambique will exacerbate the risk of widespread flooding. This risk will be particularly severe along the banks of the lower Limpopo river and Olifants river systems, as they flow through southern Mozambique, towards the floodplain region adjoining Xai-Xai in the south of Mozambique.