REPUBLIC OF KENYA MINISTRY OF ENVIRONMENT, WATER AND NATURAL RESOURCES STATE DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES KENYA METEOROLOGICAL SERVICE Dagoretti Corner, Ngong Road, P. O. Box 30259, Nairobi, Kenya, Telephone: 254-20-3867880-5, Fax: 254-20-3876955/387373, E-mail:[email protected] REVIEW OF THE WEATHER IN JANUARY AND THE OUTLOOK FOR FEBRUARY 2015 Issue Date: 30/01/2015 Ref N: KMD/FCST/4-2015/MO/02 1. SUMMARY 1.1 RAINFALL PERFORMANCE IN JANUARY 2015  Most parts of the country remained sunny and dry in January 2015. However, isolated areas in southwestern Kenya and central Rift Valley recorded light rainfall amounts. The rainfall also spread to Nairobi area on 20th January when several stations in the region recorded substantial amounts of rainfall.  Higher than average day-time (maximum) temperatures were recorded at most meteorological stations in the country during the month. This was more so over Northeastern and Northwestern regions. 1.2 RAINFALL OUTLOOK FOR FEBRUARY 2015  February is normally a sunny and dry month over most parts of the country (see figure 2). The forecast for February 2015 indicates that the entire country will still be generally sunny and dry throughout the month. A few areas in western Kenya and central Rift Valley are, however, likely to experience light rainfall amounts that may occasionally spread to the central regions.  Most parts of the country are likely to experience higher than average maximum temperatures. The night-time (minimum) temperatures are, however, expected to be quite low as a result of the expected clear skies during the night. 2. WEATHER PATTERNS IN JANUARY 2015 2.1 JANUARY 2015 RAINFALL PERFORMANCE Sunny and dry weather conditions dominated over most parts of the country during January 2015. The monthly rainfall totals recorded at most meteorological stations barely exceeded 5mm. However, a few areas mainly in southwestern Kenya and central Rift Valley recorded light rainfall amounts. This rainfall occasionally spread to Nairobi area. Wilson Airport station in Nairobi, for example, recorded 36.0mm on 20th January while on the same day; Dagoretti Corner station recorded 19.3mm. Other significant daily rainfall amounts recorded during the month include 27.0mm at Narok on 10th, 14.0mm at Moi Airbase (Eastleigh) on 20th and 13.7mm at Kisii on 22nd January. Up to 30th January, Narok station recorded the highest monthly rainfall total of 70.4mm as compared to its January long-term mean (LTM) rainfall of 86.3mm. Wilson Airport, Dagoretti Corner, Kisii and Moi Airbase stations recorded 36.0mm (recorded in one day), 19.3mm (recorded in one day), 15.9mm and 14.0mm (recorded in one day) respectively. The rest of the stations recorded less than 10mm. Indeed, all the stations in Northwestern, Northeastern, the Coastal strip and the better part of Southeastern Kenya recorded no rainfall at all as depicted in 1 Figure 1 below. 2.2 TEMPERATURE CHARACTERISTICS Most parts of the country recorded higher than average daytime temperatures during the month. This was more so in northwestern and northeastern Kenya and some parts of western and central highlands as well as southeastern lowlands. Thika meteorological station recorded the highest deviation from average of +3.4oC while Jomo Kenyatta International Airport, Kakamega, Makindu, Kitale and Meru stations recorded deviations of +2.6oC, +2.6oC, +2.3oC, +2.1oC and +2.1oC respectively. The highest daily maximum temperature of 39.1oC was recorded at Wajir Meteorological station in Northeastern Kenya on 16th January. The same station recorded the highest average maximum temperature of 37.5oC, 1.8oC higher than its long-term mean (LTM) of 35.7oC. Nighttime temperatures on the other hand were near average over most parts of the country. The minimum temperature at Marsabit station was, however, 2.3oC higher than average while the one at Nyahururu was 1.3oC lower than average. The Nyahururu station recorded the lowest daily minimum temperature of 3.4oC on 2nd January as well as on 4th and 16th January. The same station recorded the lowest average minimum temperature of 5.8oC, 1.3oC lower than its LTM of 7.1oC. 3. PREVAILING SYNOPTIC CONDITIONS The rain bearing Inter-Tropical Convergence Zone (ITCZ) remained further south in Tanzania. Warmer than average sea surface temperatures (SSTs) were observed over the El-Niño areas, especially in Central Equatorial Pacific Ocean. Cooler than average SSTs were observed in the western Equatorial Indian Ocean adjacent to the East African Coast while warmer conditions prevailed to the west of Australia. This constituted a negative Indian Ocean Dipole (IOD) that led to generally sunny and dry weather conditions over most parts of the country. Very warm conditions were also dominant over the Mascarene region to the east of Madagascar and the St. Helena region in the southern Atlantic Ocean. 4. EXPERIENCED IMPACTS The sunny and dry weather conditions were associated with the following impacts:  Loss of crops that had yet to mature following the poor performance of 2014 short-rains over the better part of the country and high evaporation rates due to high temperatures;  Deterioration of foliage and pasture as well as water in several pastoral areas of Northwestern, Northeastern and Southeastern Kenya where the 2014 shortrains performance was generally poor coupled with the very high January 2015 temperatures.  Reduction in water levels in the Seven-Folks hydroelectric power generation dams as a result of the very high temperatures recorded during the month of January.  Timely land preparation (cultivation) in readiness for the “Long Rains” season in March-April-May. 5. FORECAST FOR FEBRUARY 2015 2 This forecast is based on the expected evolution of global SSTs patterns and average performance of rainfall during previous years when the December-January SSTs behaved in a similar manner to the current trend. The current cooler than average SSTs in the western Equatorial Indian Ocean adjacent to the East African Coast coupled with warmer SSTs in the eastern Equatorial Indian Ocean adjacent to Australia and the very warm conditions over the Mascarene and the St. Helena regions were taken into account. The outlook for February 2015 (Figure 3) indicates that most parts of the country will remain generally sunny and dry throughout the month. Very few areas within the Lake Basin, Southwestern Kenya and central Rift Valley are, however, likely to observe a few days of light to moderate rainfall that may also spread to the central parts of the country. The specific outlooks for individual areas are as follows: The Lake Basin (Kisii, Kisumu, Busia) and parts of Highlands west of the Rift Valley (Kericho, Kakamega) and Central Rift Valley (Narok, Nakuru) are expected to remain generally sunny and dry. A few areas may, however, experience occasional afternoon showers and thunderstorms especially the areas to the south of Lake Victoria basin. The Central Highlands including Nairobi (Nyeri, Embu, Meru, Nyahururu, Murang’a, Dagoretti, Wilson, JKIA) are expected to remain sunny and dry for most of the month. A few areas may, however, experience one or two days of afternoon showers emanating from western Kenya. The North-western (Lodwar, Lokitaung, Lokichoggio), North-eastern (Moyale, Marsabit, Wajir, Mandera, Garissa), South-eastern (Machakos, Makindu, Voi, Taveta) and the Coastal Strip (Mombasa, Malindi, Lamu, Tana River) are expected to be mainly sunny and dry throughout the month. 6. POTENTIAL IMPACTS The projected sunny and dry conditions in February 2015 are likely to result in:        Enhanced cultivation of land in readiness for the 2015 “Long-Rains” season; Formation of frost in some parts of western and central highlands as well as the central Rift Valley where high day-time temperatures and low night-time temperatures are expected; Further reduction of foliage and pasture in the pastoral areas of Northwestern, Northeastern and Southeastern Kenya is expected. This may lead to loss of livestock if contingency measures are not put into place; Enhanced water scarcity especially in Northeastern and Northwestern Kenya as the month progresses; Problems associated with dust or dust storms may arise in some areas as result of dry conditions, particularly in Northern and Northeastern parts of the country; High chances of wild fires as a result of dry vegetation and funneling effects due to strong winds; The water levels in the Seven-Folks hydroelectric power generation dams are expected to lower further due to the expected dry conditions and high daytime temperatures expected in February. 3 This forecast should be used in conjunction with regular updates issued by this Department. MR. JAMES G. KONGOTI DIRECTOR OF METEOROLOGICAL SERVICES AND PERMANENT REPRESENTATIVE OF KENYA WITH WMO TOTAL 120.0 LTM(JAN) 80.0 60.0 40.0 20.0 MTWAPA MOMBASA MALINDI MSABAHA VOI LAMU MAKINDU THIKA MACHAKOS JKIA WILSON M.A.B. LAIKIPIA EMBU DAGORETTI Stations MERU NYERI NAROK NAKURU KISUMU NYAHURURU KISII KERICHO ELDORET ELDORET AP KAKAMEGA KITALE MANDERA WAJIR GARISSA MOYALE LODWAR 0.0 MARSABIT Rainfall (mm) 100.0 Figure 1: January 2015 Rainfall performance Fig. 2: Normal Rainfall Patterns in February Fig. 3: Expected Rainfall Performance in February 2015 4