Short rains are yet to come, the Tanzania Meteorological Agency (TMA) has said, attributing the downpour in Dar es Salaam on Monday to the horizontal transfer of moisture (advection) from the sea coupled with convergence over the entire coast.
TMA Director General Dr Agnes Kijazi told The Guardian yesterday that the short rains are yet to start in Dar es Salaam although they have already started in the Lake Victoria Basin.
Dar es Salaam is among northern coast regions that expect short rains from this month.
Said Dr Kijazi: “I would like to inform the public that the rain was due to advection of the moisture from the sea. The rain might go on for one some days only.”
She added: “This doesn’t mean that people should relax without doing something to drainage systems to allow water to flow through and avoid the consequences that may result into floods as we wait for the coming rain season.”
Last month, Dr Kijazi told a news conference that the onset of short rains is expected to start in September over Lake Victoria Basin and gradually spread to other areas. Heavy rainfall can be experienced even in areas where below normal rainfall is expected. As such local authorities should take precautions on the unexpected outcomes, she said.
She explained that the October to December rainfall season is expected to be below normal over the northern coast (Dar es Salaam, northern Morogoro and coastal regions.
They include Unguja and Pemba islands) western areas (Tabora and Kigoma), parts of Mwanza, Simiyu and Shinyanga regions. Others are much of north eastern highlands (Manyara and Kilimanjaro regions).
In the Lake Victoria Basin (Kagera, Geita and Mara regions), northern Kigoma and northern parts of Arusha and Kilimanjaro regions, rains are likely to be normal.
Dr Kijazi said the short rain season was expected to start during the second week of September over Kagera Region and Northern Kigoma areas and gradually spread to Mara, Mwanza, Geita, Shinyanga and Simiyu regions during the third week of October.
Most areas in the Northern Coastal areas and hinterland, including Dar es Salaam, Tanga and Coast regions, extreme northern Morogoro areas and Isles of Unguja and Pemba will start receiving below normal rainfall in the third week of October, she said.
North-eastern Highlands - Kilimanjaro, southern parts of Arusha and Manyara regions - will start receiving below normal rains in the fourth week of October, she said, noting however that northern parts of Arusha and Kilimanjaro regions are likely to experience normal rains.
Although short rains are expected to improve the condition of pastures and water availability for livestock, this may not be sufficient in areas expected to receive below normal rains. Constituting large numbers of national parks and game reserves, they will be characterised by livestock activities.
Dr Kijazi said the seasonal rains of November to April, which are more important to the western, central, southwestern highland, southern regions and southeastern coast, are likely to be normal over most unimodal regions.