1. CLIMATIC AND ENVIRONMENTAL CONDITIONS OVER AFRICA. 1.1 Inter-Tropical Discontinuity (ITD)

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African Centre of Meteorological Application for Development Centre Africain pour les Applications de la Météorologie au Développement DECEMBER 2011 HIGHLIGHT: Cholera, Yellow fever, Avian Influenza,

Heavy rainfalls with localised floods were observed over some parts of GHA, Central Africa and Southern Africa countries.

1 Inter-Tropical Discontinuity (ITD) The ITD is the demarcation line between north/north-eastern winds from the Sahara (hot, dry and dusty) and south/south-western winds from Atlantic Ocean (cool and

Between the first dekad (red line) and the second dekad (blue line) of December 2011, the ITD continued its southwards migration over the domain with a mean displacement of 1 degrees of latitude.

1 African Centre of Meteorological Application for Development Centre Africain pour les Applications de la Météorologie au Développement DECEMBER 2011 HIGHLIGHT: Cholera, Yellow fever, Avian Influenza, typhoid and Meningitis are the disease affecting some African countries as reported by some sources. Heavy rainfalls with localised floods were observed over some parts of GHA, Central Africa and Southern Africa countries. Rainfall deficits were observed over some parts of Southern Africa, Central Africa countries and north-western part of Northern Africa. 1. CLIMATIC AND ENVIRONMENTAL CONDITIONS OVER AFRICA 1.1 Inter-Tropical Discontinuity (ITD) The ITD is the demarcation line between north/north-eastern winds from the Sahara (hot, dry and dusty) and south/south-western winds from Atlantic Ocean (cool and moist) as seen in Figure 1. Between the first dekad (red line) and the second dekad (blue line) of December 2011, the ITD continued its southwards migration over the domain with a mean displacement of 1 degrees of latitude. Between the second dekad (blue line) and the third dekad (black line), the ITD had a southwards migration with about 2 degrees of latitude over the extreme western part (off coast and over Guinea) while its was quasistationary over Côte d Ivoire and Ghana and migrated northwards with about 3 degrees over the eastern part of the domain (from Togo up to central African Republic). 1.2 Dust Haze The figure 2 below shows mean dust events in the month of December 2011 from WMO SDS-WAS Programme: BSC-DREAM8b model shows the dust loading particles (0.1 to 0.4 g/m 2 ) over some localities above 12 N and north-eastern part of GHA countries, intensifying with dust loading particles ranging from 0.4 to 0.8 g/m 2 over north western of Chad. Figure 1: Dekadals ITD position Figure 2: Dust loading particles Source: Barcelona Supercomputing Center 1

1.3 Rainfall The figure 3 below on estimated cumulative rainfall shows spatial distribution of rainfall along with observed amounts where: North Africa countries had some rainfall amounts ranging

Gulf of Guinea countries: had only the coastal zone of Côte d Ivoire with rainfall amounts ranging from 20mm to 100mm. The northern part remained under the influence of Harmattan.

2 1.3 Rainfall The figure 3 below on estimated cumulative rainfall shows spatial distribution of rainfall along with observed amounts where: North Africa countries had some rainfall amounts ranging between 20mm to 100mm over northern Algeria and Tunisia. The Sahel countries were under the influence of the Harmattan characterised by cool, dry and dusty winds from the Sahara. Gulf of Guinea countries: had only the coastal zone of Côte d Ivoire with rainfall amounts ranging from 20mm to 100mm. The northern part remained under the influence of Harmattan. Central Africa countries had rainfall amounts ranging from 10mm to 300mm over the southern part, increasing to the maximum amount of about 600mm over Democratic Republic of Congo. GHA countries had amounts ranging between 20mm to 400mm over most southern part with localized high amounts between 400mm to 600mm over Tanzania. Southern Africa countries: had rainfall amounts ranging from 10mm to 400mm with maximum of above 800mm over Zambia, Namibia and Botswana. The December 2011, rainfall anomaly derived from long-term mean period of (Figure 4), shows rainfall deficits over northern part of central Africa countries, South-eastern part of GHA, eastern part of southern Africa and extreme north-western and north-eastern parts of Northern Africa countries while excessive rainfall was observed over extreme southern part GHA and northern part of southern Africa countries. Figure 3: Monthly cumulative rainfall for Deceember2011 Data Source: NOAA/NCEP Figure 4: Monthly Rainfall anomalies for December 2011 Data Source: NOAA/NCEP 1.4 Relative Humidity The mean relative humidity map (Figure 5) shows that the month had high surface relative humidity ranging from 60% to 100% over southern part of the Gulf of Guinea countries, most of Central Africa, southern part of GHA countries and northern and eastern parts of southern Africa including Madagascar. However, low relative humidity (<40%) prevailed over most of the Sahel, the Sahara, southern part of Northern Africa above 10 N latitude as well as western part of Southern Africa. 2

1.5 Air Temperature The temperature map below (Figure 6) shows that, most of African countries

The exception is that the northern parts of the continent above 15 N experienced temperature

Figure 5: Surface Relative Humidity Source: NOAA/NCEP Figure 6: Mean air temperature Source:

6 Vegetation Index The EVI-MODIS images from 19 th to 31 st December, 2011 (Figures 7a, 7b and

Central Africa countries, southern part of GHA countries including Ethiopian highlands, northern

3 1.5 Air Temperature The temperature map below (Figure 6) shows that, most of African countries experienced temperatures ranging from 18 C to 32 C (shaded area). The exception is that the northern parts of the continent above 15 N experienced temperature below the above threshold. Figure 5: Surface Relative Humidity Source: NOAA/NCEP Figure 6: Mean air temperature Source: NOAA/NCEP 1.6 Vegetation Index The EVI-MODIS images from 19 th to 31 st December, 2011 (Figures 7a, 7b and 7c) displayed high vegetation cover over southern part of the Gulf of Guinea countries, most of Central Africa countries, southern part of GHA countries including Ethiopian highlands, northern and eastern parts of southern Africa. Elsewhere, had low to none existence of vegetation cover. The breeding of mosquitoes was high in areas with thick vegetation cover as shown in these regional images. Figure : 7a Figure: 7b Figure: 7c EVI images: 19 th to 31 st December 2011, Source: IRI 3

4 2. CLIMATE RELATED DISEASES During December 2011, outbreaks of cholera were observed in Democratic Republic of Congo, Kenya and Malawi as reported in Pro-Med mail and Relief Web. According to the same sources yellow fever was observed in Côte d Ivoire and Senegal; Avian influenza in Zimbabwe; suspected cases of H1N1 in Namibia; typhoid fever in Zimbabwe and Meningitis in South Africa. The wet conditions with the prevailing high temperatures and vegetation cover in several parts of Africa continued to support the breeding of mosquitoes and increased incidences of malaria over several parts of the Continent. On the epidemiologic situation of the meningitis, there were low cases over the African meningitis belt from 31 st October to 24 th November A total number of 313 isolated cases with 61 deaths reported with no district on alert and none in epidemic situation. The spatial distribution is as follows: Benin (11 cases with 0 death), Burkina Faso (151 case with 17 deaths), Côte d Ivoire (0 cases with 0 death), Ghana (47 case with 36 deaths), Mali (23 cases with 0 death), Niger (13 cases with 4 deaths), Nigeria (55 cases with 1 death), and Togo (13 cases with 3 deaths). 3. OUTLOOKS The ITD will continue its southwards migration, leading to the reduction of moisture influx into the atmosphere over most parts of the Sahel and the Gulf of Guinea countries. These regions will still be under the influence of the Harmattan characterised by dry, cold and dusty winds. However, southern parts GHA, central Africa and most southern African countries will continue to receive significant amounts of rainfall with localised floods. The heavy rainfall with floods may cause damages on life and property over some parts of central, southern Africa as well as some parts of GHA countries. The epidemiological situation of the meningitis over African belt will have increased cases of the meningitis of remain calm with few sporadic cases. However, due to the strong influence of the Harmattan over the Sahara, the Sahel and northern part of the Gulf of Guinea countries. The observed and expected heavy rainfall with localized floods over southern part of GHA, central Africa countries, northern and eastern parts of Southern Africa countries could lead to increased outbreaks of malaria and other water borne diseases such as cholera, diarrhoea, etc. 3.1 Malaria The incidences of malaria will be higher in areas with high temperatures especially in the range of 18 C to 32 C, high relative humidity (above 60%)/rainfall and thick vegetation cover providing conducive environmental conditions for the survival of the vector and development of the parasites. Based on the above conditions (climatic and environmental parameters) observed during the past month and conditions expected for the next month, the most vulnerable parts to incidences of malaria will be in southern part of the Gulf of Guinea countries, central Africa countries, extreme southern part of GHA including the Ethiopian highlands, northern and eastern parts of Southern Africa countries. 3.2 Meningitis Based on climatic parameters (low/no rainfall, low relative humidity, high temperature range, dusts episodes, etc) the meningitis epidemiologic season will continue to be calm over African belt with slight increase in the cases due to the intensifying effect of Harmattan. 4

surveillance to guard against the spread of cholera outbreaks and other water borne diseases. 3.

5 3.3 Cholera During the month of December 2011, heavy rainfalls with floods were observed in Kenya and Democratic Republic of Congo. This country, as well as countries with excessive amounts of rainfall in Figure 4 (southern Tanzania, south-eastern Angola, northern Botswana, western Zambia and western Zimbabwe) has to be under surveillance to guard against the spread of cholera outbreaks and other water borne diseases. 3.4 Flu and others respiratory diseases Areas under the influence of the Harmattan (the Sahara, the Sahel countries, and northern part of the Gulf of Guinea countries), will continue to observe increase of the incidences of flu and other respiratory diseases such as asthma, bronchitis, flu, etc. 3.5 Seasonal Rainfall Outlook of central Africa for OND 2011 by ACMAD issued in September Zone I covering Equatorial Guinea, Sao Tome et Principe, the coastal area of Cameroun, most part of Gabon and coastal part of Congo, will have above normal rainfall. Zone II including south-east Cameroun, south-west of Central African Republic, east Gabon, central and north of Congo and part of western Democratic Republic of Congo will be characterized by normal to below normal rainfall. Zone III, covering the extreme south of Chad, central part of Cameroon, most part of Central Africa Republic and democratic Republic of Congo will be characterized by normal rainfall. Figure 12: Precipitation Outlooks Valid for October- November-December 2011 over Central Africa. 3.6 Seasonal Rainfall Outlook for west Greater Horn of Africa for SOND 2011 by IC ICPAC issued in September Zone I: normal to below normal rainfall over western Tanzania; southern Burundi and southwestern Rwanda. Zone II: normal to above normal rainfall over much of Tanzania; northern Burundi; much of Rwanda; western Kenya as well as southern and central Uganda. Zone III: above to near normal over northeastern and northern coast of Tanzania; coastal, central and northeastern Kenya; extreme southern Ethiopia as well as southern and central Somalia. Zone IV: normal to below normal rainfall over northern Somalia; eastern and southern Ethiopia; northwestern Kenya and northern Uganda. Zone V: normal to above normal rainfall over much of South Sudan; western, central and northern Ethiopia and Djibouti. Zone VI: generally dry conditions over Sudan; northern Ethiopia and much of Eritrea. Figure 9 : GHA Climate Outlook for September to December

3.7 Southern Africa Rainfall Outlook (SARCOF-15) for OND 2011 issued in September Zone 1 (The extreme north of the DRC): Increased chances of normal to below-normal rainfall Zone 2 (North-eastern

6 3.7 Southern Africa Rainfall Outlook (SARCOF-15) for OND 2011 issued in September Zone 1 (The extreme north of the DRC): Increased chances of normal to below-normal rainfall Zone 2 (North-eastern half of Tanzania): Increased chances of above-normal rainfall Zone 3 (North-western half of Angola, the bulk of DRC, south-western half of Tanzania, extreme north-eastern parts of Zambia, northern half of Malawi and north eastern Mozambique): Increased chances of normal to above-normal rainfall Zone 7 (Western Madagascar): Increased chances of normal to below-normal rainfall Zone 8 (Eastern Madagascar): Increased chances of normal to above-normal rainfall Zone 9 (Southern Madagascar): Increased chances of above- normal to normal rainfall Zone 10 (Mauritius): Increased chances of normal to above-normal rainfall Zone 4 (Central South Africa, south-western half of Lesotho, western half of Botswana, most of Namibia, south-eastern half of Angola, extreme south of DRC, central parts of Zambia, southern half of Malawi, north-eastern half Zimbabwe and central Mozambique): Increased chances of normal to belownormal rainfall Zone 5 (North-eastern half of Lesotho, north-eastern parts of South Africa, Swaziland, southern parts of Mozambique, south-western half of Zimbabwe, eastern half Botswana and southwestern Zambia): Increased chances of normal to below-normal rainfall Zone 6 (The west coastal areas of South Africa, Namibia and the extreme south-western Angola): Increased chances of normal to below-normal rainfall Figure14: Rainfall forecast for October-December 2011 ADVICE: Detailed climate analyses and forecasts at the country scale (including rainfall amounts and the onset) are available from National Meteorological Services. The high rainfall variability in the region may cause risks with adverse effects throughout the season, particularly on Life and property (flooding) on plants (locust invasion) and Public Health (malaria epidemics and other waterborne diseases such as cholera). We are calling upon the public health sector and humanitarian Agencies to maintain vigilance and make timely responses. 6

African Centre of Meteorological Applications for Development Centre Africain pour les Applications de la Météorologie au Développement

African Centre of Meteorological Applications for Development Centre Africain pour les Applications de la Météorologie au Développement Ten Day Climate Watch Bulletin N 34 Dekad 1 st to 10 th December,