CLIMATE OUTLOOK FOR TANZANIA MARCH – MAY, 2017 MASIKA RAINFALL SEASON

THE UNITED REPUBLIC OF TANZANIA

MINISTRY OF WORK, TRANSPORT AND COMMUNICATION

TANZANIA METEOROLOGICAL AGENCY

CLIMATE OUTLOOK FOR TANZANIA

MARCH – MAY, 2017 MASIKA RAINFALL SEASON

Hghlights for March –May, 2017 Masika rainfall Season This statement gives evolution of the climate systems and outlook for the March to May, 2017 rainfall season, advisories and early warnings to various weather sensitive sectors such as, Agriculture and food security, Livestock and wildlife, Natural Resources and Tourism, Energy and water, Local Authorities, Health sector and Disaster Management. The Outlook for March to May 2017 Masika rainfall season indicates that:- a) Outlook for March to May 2017 Masika rainfall season: For the period of March to May 2017, Masika rains are likely to be mainly normal over most areas of the country. However, there is likelihood of normal to below rainfall with long dry spells over areas of the North-eastern Highlands (Arusha, Kilimanjaro and Manyara) and Northern Coast (Morogoro, Coastal Region, Dar es Salaam, Tanga and Isles of Unguja and Pemba). The ongoing rains over few areas of the Lake Victoria Basin and Few areas of Northern Coast are expected coincide with the commencement of the Masika rains in the first to second week of march, 2017. Meanwhile, the Seasonal rains which started in November 2016 are expected to progress well over most part of unimodal areas, where (Dodoma, Singida, Kigoma, Tabora, Rukwa, Katavi, Mbeya and Iringa) are likely to experience normal to above normal rains. Above normal rains are likely over Njombe, Ruvuma, Lindi, Mtwara and southern parts of Morogoro (Mahenge), with a likelihood of prolonged seasonal rains over same areas. b) Expected Impacts Despite of the expected slight improvement in availability of water and Pasture high likelihood of dry spells may results to poor and persistent pasture shortage particularly over areas with normal to below normal rainfall. Areas expected to receive below normal rains are anticipated to experience shorted of water and this may elevate outbreak of waterborne diseases. Incidences of heavy rainfall and floods may occur and result into various impacts including waterlogging affecting post-harvesting of crops particularly in areas where prolonged rainfall season is likely.

(I) SEASONAL RAINFALL OUTLOOK MARCH - MAY 2017

Based on current and expected climate systems (As indicated in part II of this outlook), there is an elevated chance of normal rains over most parts of the country.  However, poor rainfall distribution and high risk for dry spells over some areas particularly over Northeastern Highlands and northern coast during the March to May 2017 rainfall season is likely.  On the other hand seasonal rains that started in November 2016 over areas with unimodal rainfall regime are likely to be normal to above normal over most areas. Details of the rainfall season are as follows:

1. March to May Season rains (Masika) over Bimodal areas

The March to May 2017 (MAM) rainfall season (Masika) is more significant for the areas over the Northeastern highlands, northern coast including the Isles of Unguja and Pemba, Lake Victoria Basin and the northern parts of Kigoma. The March to May 2017 rains are expected to be normal to above normal over the Lake Victoria Basin and normal to below normal over northern coast and Northeastern Highlands.

The ongoing rains that have started over some parts of the Lake Victoria Basins and northern coast are likely coincide with seasonal rains and spread over the remaining part during the first to second week of March, 2017. Dry spells are likely to dominate over some areas of northern coast and northeastern highlands particularly during the month of March, 2017. The Masika rains are likely to be influenced by the expected occurrences of Tropical Cyclones over the Indian Ocean.

1.2 Lake Victoria Basin: (Kagera, Mara, Mwanza, Geita, Simiyu and Shinyanga regions):

Rains that have started over Kagera and Mwanza regions are expected to spread to other regions of Geita, Mara, Simiyu and Shinyanga regions during the first to second week of March 2017. The rains are expected to be above normal to normal over Kagera, Mwanza, Simiyu, Shinyanga and Geita regions.

1.3 Northern Coast areas and its Hinterlands: (Dar es Salaam, Tanga, and Coast regions, Islands of Unguja and Pemba and northern Morogoro areas):

Ongoing rains that started over few areas of Dar es Salaam and Coastal regions and are expected to coincide with the start of Masika rains in the first to second week of March, 2017. The rains are expected to be normal to below normal with likelihood of long periods of dry spells.

1.4 North-Eastern Highlands: (Kilimanjaro, Arusha and Manyara regions):

Rains are expected to start over most areas in the first to second week of March 2017 and are likely to be normal to below normal over most areas with likelihood of dry spells over few areas.

2. Seasonal Rainfall (November to April) over Unimodal areas:

Seasonal rains are more significant for unimodal areas (Western, Central, Southwestern Highlands, Southern region and Southern Coast).   Rainfall in these areas have started in November, 2016 and is progressing well over most areas.  The rains over most parts of these areas are expected to be mainly normal to above normal. However, above normal rains are expected over Njombe, Songwe, Ruvuma, Mtwara and southern part of Morogoro and Lindi regions. There is likelihood of late cessation of the ongoing seasonal rains over most parts of the unimodal areas.

2.1 Western areas: (Tabora, Rukwa, Katavi and Kigoma regions):

The overall rainfall performance is expected to be normal to above normal over most parts of the regions. The rains are expected to end earlier during the second to third week of April 2017.

2.2 Central (Singida and Dodoma regions):

Rains are expected to be normal to above normal over most parts of the region. The rains are expected to end during the second to third week of April, 2017.

2.3 Southwestern highlands: (Mbeya, Songwe, Iringa, and Njombe regions and southern Morogoro areas):

Rains are expected to be normal to above normal over most parts of the region during the remaining period with high chance of above normal rainfall over Songwe, Njombe, and southern Morogoro areas. The rains over these areas are expected to end during the fourth week of April, 2017.

2.4 Southern Region and Southern Coast: (Ruvuma, Mtwara and Lindi regions):

RAINFALL OUTLOOK  MARCH-MAY 2017	LONG TERM MEAN RAINFALL (mm)

Rains are expected to be above normal-to-normal over most parts except for northern part of Lindi region where normal to above normal rains are expected. The rains are expected to end during the fourth week of April to first week of May 2017.

Figure 1 – right: Climatological long term average (normal) rainfall for March to May; left: Outlook for the coming rainfall season March to May 2017

It should be noted that events of heavy and short duration of rainfall might feature even over area of normal and below normal rainfall conditions.

(II) CLIMATE SYSTEMS OUTLOOK

The observed gradual warming over Central Equatorial Pacific Ocean is likely to persist through the season resulting to Neutral Sea Surface Temperatures for the months of March to May 2017. A gradual warming condition is also expected over the entire tropical Indian Ocean. Moreover, enhanced warming conditions across the Southwestern Indian Ocean during the months of March to May, 2017 are likely to enhance occurrence of tropical cyclones during the season. Slightly cooling over South-east Atlantic Ocean near Angola coast particularly during the months of April to May 2017 is likely to enhance westerly wind flow from Congo Basin towards the country resulting into moisture influx into the country.  

(III) LIKELY IMPACTS AND ADVISORY

Agriculture, Food Security and Livestock Production

Soil moisture levels are likely to improve slightly for crop and pasture production over northeastern highlands (Arusha, Manyara and Kilimanjaro) and Northern Coast (Tanga, Dar es Salaam, Pwani, northern Morogoro and islands of Unguja and Pemba). However, the likelihood of below normal rainfall associated with long dry spells over these areas is likely to affect crop performance.   Pastoralist should be sensitized and advised to harvest their cattle while in good condition. Livestock keepers should be encouraged to keep livestock according to the capacity of grazing areas and to seek more advice from agricultural and livestock extension officers in their areas.

Energy and water

Over northeastern highlands and northern Coast, water levels over the Lakes, Dams and Rivers are not expected to have significant improvement from the current levels, thus efficient use of water for irrigation and improved power generating plans with regards to energy mix are highly advised. However, areas where above normal rainfall is expected significant improvement of water level in dams are likely to occur.

Local Authorities

Due to the fact that short periods of heavy rains are also expected during the rainy season water drainage systems should be opened and cleaned so as to avoid water accumulation due to surface runoff and floods that may cause damage of infrastructures, loss of lives and property. Similar actions should also be considered even in areas with normal to below normal rains due to anticipated short periods of heavy rains.

Health sector

Due to the anticipated shortage of water over areas expected to receive below normal rainfall communities may be forced to utilize unsafe water so there is a likelihood of outbreak of water borne diseases. Relevant Authorities concerned with public health and individuals are advised to take necessary appropriate health measures needed to minimize the expected negative impacts on health.

Disaster Management

Disaster management authorities and other stakeholders are advised to take necessary measures such as good practice of environmental conservations and ensure preparedness, response, and mitigation plans are in place to reduce any negative impacts that may result from the expected rainfall.

Media

The media is advised to obtain, make regular follow-up and disseminate weather and climate information and warnings including the updates as provided by appropriate Warning Authority i.e. the Tanzania Meteorological Agency - TMA. Moreover, Media is encouraged to seek and obtain inputs from relevant sectors when preparing and communicating cross cutting issues related to Weather and Climate to the Public.

Tanzania Meteorological Agency (TMA) advises all users of weather information including farmers, livestock keepers, wildlife conservation authorities, hydrological and health sectors to continue seeking and utilizing experts’ advice on their relevant sectors.

NB: The current status of seasonal forecasting allows for prediction of spatial and temporal averages over larger areas and may not fully account for all physical and dynamical factors that influence short-term climate variability.  Users of this outlook are, therefore urged to make good use of daily, ten day and monthly updates issued by the Tanzania Meteorological Agency.

Tanzania Meteorological Agency (TMA) will continue to monitor developments of the weather systems and issue updates whenever appropriate.

Issued by Tanzania Meteorological Agency:

Dr. Agnes L. Kijazi

Director General