TMA June 2005 Bulletin

ISSN No: 0856-0919, Volume 7, Issue 6 June 2005 JUNE - HIGHLIGHTS . Dominant East African low level jet over the coast . Persistent dry conditions favored drying of matured crops Fig. 1: June 2005 Rainfall Totals (mm) SYNOPTIC SUMMARY Lake Victoria Bukoba Musoma 2 Loliondo Ngara Mwanza uring the month of June, the ArushaMoshi Shinyanga DArabian, St. Helena and Azores Same 4 anticyclones were relatively weak Kigoma Singida Tabora Tanga Pemba while the Mascarene anticyclone and ) Handeni S L º ( a k e e Dodoma the associated ridge (East African) d 6 Zanzibar T I u n t a i d t n i a g a a MorogoroDar es Salaam n were generally intense. L n O y Iringa c ik e a a Sumbawanga n The near equatorial trough was active 8 Mahenge over the northern coast. The Mbeya Kilwa southeasterly to southerly wind flow 10 L a Mtwara k south of 5 S becoming Southwesterly e Songea ° N y a Tunduru s flow north of 5°S over the eastern a coast of East Africa, the “East African Low Level Jet” was dominant. 30 32 34 36 38 40 Longitude (ºE) WEATHER SUMMARY MEAN AIR TEMPERATURE aximum and minimum air RAINFALL Mtemperatures across the country during June are indicated in Figs. 2a ry conditions prevailed in many and 2b respectively. Observed mean Dparts of the country, except for a maximum temperature ranged few areas of Kagera region and between just above 30ºC and just northern coast including the islands below 24ºC as shown in Figure 2a. of Zanzibar and Pemba where the Areas over the southwestern monthly rainfall record was at least highlands (Rukwa, Mbeya, Ruvuma 20 mm (Fig. 1). The Highest total and Iringa regions),Mahenge and monthly rainfall was 47.7 mm Arusha continued experiencing lower (Pemba). maximum temperatures (slightly below 24°C), while higher values just Areas of Mahenge and the coastal belt above 30°C were observed over received light rains of at least 10 mm Shinyanga (30.1ºC) and Dar es during the month. Salaam (30.6ºC). Volume 7, Issue 6 June 2005 Fig. a: June Mean Maximum Temperature(ºC) ºC) was recorded during the second Lake Victoria Bukoba Musoma dekad of the month. 2 Loliondo Ngara Mwanza ArushaMoshi SUNSHINE HOURS Shinyanga Same 4 igure 3 indicates the average Kigoma Singida Tabora Tanga Pemba ) Handeni duration of bright sunshine S F L º ( a k e e Dodoma d expressed in hours per day. The 6 T Zanzibar I u n t a i d t n i a g a a Morogoro Dar es Salaam n L country experienced bright sunshine n y O i Iringa k c a e a for durations averaged between about Sumbawanga n 8 4 hours/day over northeastern Mahenge Mbeya Kilwa highlands to just about 10 hours/day (Musoma and southwestern 10 L a Mtwara k e Songea highlands). The lowest values of N y a Tunduru s a about 2 hrs/day were observed at Tanga and Kilimanjaro airports during 30 32 34 36 38 40 Longitude (ºE) the second dekad of the month. A normally dry season during June has Arusha airport in northeastern enhanced clear skies over most areas. highlands recorded the lowest mean maximum temperature of 22.7ºC (a Fig. 3: June 2005 Mean Sunshine Hours (hrs) Lake Victoria Bukoba drop of 1.7ºC from that of May). Musoma Loliondo Fig. b: June Mean Minimum Temperature(ºC) 2 Ngara Mwanza Lake Victoria Bukoba Musoma ArushaMoshi Shinyanga 2 Loliondo Ngara Mwanza 4 Same Kigoma Singida ArushaMoshi Tabora Tanga Pemba Shinyanga ) Handeni S L º Same ( a 4 k e e Dodoma d 6 T Zanzibar I u n t a Singida i d Kigoma t n i Tabora Tanga a g Morogoro Dar es Salaam a a n L Pemba n ) Handeni y O S L i Iringa c º k ( a a e k a e e 6 Dodoma Sumbawanga n d T Zanzibar I u n t a 8 i d t n i a g a a MorogoroDar es Salaam n L Mahenge n Mbeya Kilwa y O i Iringa k c a e a Sumbawanga n 8 10 L a Mtwara k Mahenge e Songea Mbeya Kilwa N y a Tunduru s a 10 L a Mtwara k e 30 32 34 36 38 40 Songea N y a Tunduru Longitude (ºE) s a 30 32 34 36 38 40 Longitude (ºE) MEAN DAILY WINDSPEED On the other hand, the mean minimum air temperatures during the ean wind run across the country month ranged from just below 8.0 ºC Mduring the month of June ranged to just above 22ºC (a drop 0f 2.0ºC from about 3 km/hr(Sumbawanga, compared to May) (Figure 2b). Songea and Morogoro municipalities) Areas over the southwestern to a maximum of about 12 km/hr highlands continued experiencing (Dodoma) as shown in Figure 4. The relatively cooler conditions lowest value of 2.6 km/hr was (temperatures less than 14ºC) with recorded over Sumbawanga while the the lowest mean minimum highest wind speed of 11.7 km/hr was temperature of 7.5ºC recorded at experienced at Dodoma airport). Mbeya airport. The lowest value (7.2 2 Volume 7, Issue 6 June 2005 Fig. 4: June 2005 Mean Windrun (km/hr) Iringa north), northeastern highlands Lake Victoria Bukoba Musoma (Manyara and Kilimanjaro regions)and 2 Loliondo Ngara Mwanza Shinyanga region. Persistence of dry conditions in June, highlights further ArushaMoshi Shinyanga decrease in NDVI and the likelihood 4 Same Kigoma Singida of the reduction in the quality and Tabora Tanga Pemba ) Handeni S supply of pastures. L º ( a k e e Dodoma d 6 T Zanzibar I u n On the other hand, small decrease or t a i d t n i a g a a Morogoro Dar es Salaam n L n no change in the SNDVI was observed y O i Iringa k c a e a Sumbawanga n over the southern region and the 8 Mahenge coastal belt, the condition which was Mbeya Kilwa attributed to light rains received in 10 L these areas during the month. a Mtwara k e Songea N y a Tunduru s a 30 32 34 36 38 40 AGROMETEOROLOGY Longitude (ºE) ost crops including annuals SATELLITE INFORMATION M(cereals and pulses) and perennials (tree crops) reached igure 5, displays the satellite harvesting stage and the persistent F imagery derived from the dry conditions accelerated them to difference between Spot Normalized full dry down. Over unimodal rainfall Difference Vegetation Indices pattern (southern, southwestern (SNDVI) of the second dekad of May highlands, western and central) areas and June 2005 indicating the changes harvesting of crops continued. that occurred during the period. On the other hand soil moisture supply from light rains over bimodal rainfall pattern (Lake Victoria basin, northeastern highlands, northern coast) enhanced favorable conditions for maize crop to reach to physiological maturity, and growth of cassava which was at various stages. Moreover, these rains also were favorable to growing sweet potatoes over the northern coast. Expected occasional rains over northern coast during July will impede drying and harvesting of maize, thereby reducing the quality of the crop. Generally, the estimated yield levels reported in many areas were below average of last year’s values. This was mainly due to insufficient soil moisture supply experienced A large decrease in vegetation during the cropping season. greenness was observed over most parts of Western, Central, southwestern highlands (Mbeya and 3 Volume 7, Issue 6 June 2005 The southeasterly wind flow south of HYDROMETEOROLOGY 5°S becoming southwesterly flow north of 5°S over the eastern coast of here has not been any increase in East Africa will be a dominant feature Twater levels in rivers and water during the month. reservoirs. Water for industrial and domestic purposes should be used EXP ECTED WEATHER SITUATION sparingly. DURING JULY ENVIRONMENTAL he northern coast (Tanga and Dar T es Salaam) and islands of indy, cooler and dry conditions Zanzibar and Pemba will experience Wacross the country that prevailed partly cloudy conditions with during the month, enhanced occasions of morning light rains over prospects for diseases such as colds, few areas and sunny periods during coughs, pneumonia and asthma. the afternoon hours. Lake Victoria Basin will feature partly cloudy EXP ECTED SYNOPTI C SITUATION conditions with few thunderstorms DURING JULY mainly over northern side of the lake and sunny periods. he Arabian and Azores anticyclones Tare expected to remain relatively Southern, Central and western areas weak while the St. Helena and will experience partly cloudy Mascarene anticyclones and the conditions with chilly mornings and associated ridge (East African) are sunny periods. Southwestern and likely to remain intense. The Inter- northeastern highlands will tropical Convergence Zone (I.T.C.Z) experience cloudy mornings with will continue to remain to the north chilly weather conditions followed by of equator while the near equatorial sunny periods during the afternoon trough will be active over the hours. northern coastal areas. Prepared by TANZANIA METEOROLOGICAL AGENCY 3rd & 4th Floors - Ubungo Plaza Ltd – Morogoro Road. P.O. Box 3056 Tel. 255 -(0) 22 – 2460706-8 ; Fax: 255 - (0) 22 - 2460718 E-mail: (1) [email protected] (2) [email protected] Dar-es-Salaam UNITED REPUBLIC OF TANZANIA 4.

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