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Home , Makindu, Mandera, Marsabit, Moyale, Wilson Airport

REPUBLIC OF MINISTRY OF ENVIRONMENT AND MINERAL RESOURCES KENYA METEOROLOGICAL DEPARTMENT Dagoretti Corner, Ngong Road, P. O. Box 30259, , Kenya, Telephone: 254-20-3867880-5, Fax: 254-20-3876955/387373,

E-mail:[email protected]

REVIEW OF THE WEATHER IN NOVEMBER AND THE OUTLOOK FOR DECEMBER 2011

Issue Date: 29/11/2011 Ref N: KMD/FCST/4-2011/MO/12

1. SUMMARY

1.1 Weather Review in November 2011 • Highly enhanced rainfall was recorded over most parts of the country during November 2011. • The rainfall was especially highly enhanced over the Northeastern, Northwestern, western Kenya and parts of central Highlands including Nairobi. Most Meteorological Stations in these areas recorded more than 125 percent of their Long-Term Means (LTMs) for the month. • However, a few stations along the Coastal strip recorded depressed rainfall (< 75% of the LTMs).

1.2 The forecast for December 2011 The month of December normally marks the end of the “Short-Rains” (October-November-December) season over most parts of the country. The outlook for December 2011 indicates that: • The western sector of the country is likely to continue receiving enhanced rainfall. • Most of the eastern sector is likely to experience slightly depressed rainfall. • The seasonal rainfall is expected to cease within the first to second week of December over most parts of the Northern Counties while cessation over the Western, Central and Southern Counties is expected within the third to fourth week of December.

2. WEATHER REVIEW FOR NOVEMBER 2011 November is normally the peak rainfall month for the “Short Rains” (October to December) rainfall season over most parts of the country. During November 2011, most parts of the country experienced highly enhanced rainfall persisting from the conditions in October 2011. The rainfall was well distributed both in time and space. The most enhanced rainfall was recorded in Northwestern, Northeastern and western highlands where stations like , , , and recorded more than 300 percent of their LTMs for November. Eldoret (Kapsoya), , and stations recorded over 200 percent. In the Central highlands including Nairobi, most stations recorded above normal rainfall (more than 125 percent of their LTMs) while in Southeastern Kenya, station also recorded highly enhanced rainfall of over 250 percent of its LTM. Along the Coastal strip, and Msabaha recorded above 180 percent of their LTMs but stations like in Northeastern Kenya and , Mtwapa and along the Coastal strip recorded depressed rainfall (less than 75 percent of their LTMs). The stations recorded rainfall that was 71%, 64%, 54% and 46% of their November LTMs respectively.

In terms of amounts, Marsabit Meteorological Station recorded the highest rainfall amount of 477.3mm (342%) as compared to its November LTM of 139.6mm. Meru, Voi, Kisii, , Kitale, Kakamega, Eldoret Airport and stations recorded 466.6 mm (144%), 348.0 mm (270%), 312.6 mm (152%), 303.7 mm (191%), 301.5 mm (331%), 289.2 mm (203%), 264.8 mm (411%) and 258.0 mm (179%) as compared to their LTMs of 323.4, 129.1, 206.2, 159.0, 91.2, 142.3, 64.4 and 143.9 mm respectively. Jomo Kenyatta International Airport, Moi Airbase, Moyale, Mandera, Embu and Wilson Airport stations recorded between 200 and 250 mm while the rest of the stations in the country recorded less than 200

1 mm. Figure 1a shows the total rainfall amount recorded in November (blue bars) as compared to the November LTMs, (red bars), while figure 1b shows the spatial rainfall distribution as a percentage of the November LTMs.

3. REVIEW OF THE OCTOBER-NOVEMBER-DECEMBER (OND) 2011 SEASONAL RAINFALL PERFORMANCE The seasonal rainfall analysis up to the end of November 2011 indicates that the performance was quite good at most stations. All the stations in the country except in Southeastern Kenya recorded more than 75 percent of their seasonal LTMs. Indeed, stations like Wajir and Lodwar recorded above 300 percent while Mandera, Msabaha, Marsabit, Malindi and Lamu recorded above 200 percent.

The highest seasonal amount of 869.5mm (126%) was recorded at Meru while Marsabit, Kisii,,Kericho, Wajir, Kakamega, Msabaha, Embu, Moyale, Kisumu and Voi stations recorded 716.2 (242%), 521.6 (97%), 514.2 (127%), 504.5 (363%), 479.9 (121%), 455.5 (247%), 445.3 (84%), 436.6 (177%), 405.5 (115%) and 402.2mm (144%) respectively. The rest of the stations recorded less than 400 mm. Figure 2a shows the total rainfall amount recorded in October-November (blue bars) as compared to the OND LTMs, (red bars), while figure 2b shows the October-November spatial rainfall distribution as a percentage of the OND LTMs.

4. THE PREVAILING GLOBAL SEA SURFACE TEMPERATURES (SSTs) CONDITIONS The highly enhanced rainfall in the country was associated with the warm SSTs in the Equatorial western Indian Ocean (adjacent to the East African Coast). This resulted into strong and moist easterly winds from the Indian Ocean that highly increased the moisture influx to the country. The SSTs in the Eastern and Central Equatorial Pacific Ocean remained at La-Niña level. The signal from the Pacific Ocean was, however, not echoed by the Indian Ocean and hence the enhanced rainfall.

5. EXPERIENCED IMPACTS The enhanced rainfall performance in the country has led to both positive and negative impacts on various socio-economic sectors.

5.1 Positive Impacts (i). Good crop performance in the agricultural areas of the central highlands and southeastern Kenya; (ii). The performance of pasture for livestock in the pastoral areas of Northeastern Kenya was also generally good due to the highly enhanced rainfall in the region; and (iii). The level of water for hydroelectric power generation was expected to rise significantly due to the enhanced rainfall in the catchment areas.

5.2 Negative impacts (i). Harvesting activities in Trans Nzoia and Uasin Gishu have been hampered by the heavy rains; (ii). Between 7th and 13th November 2011, the heavy downpour that occurred at interrupted water supply to more than 50,000 residents; (iii). On November 9th 2011, heavy rainfall disrupted Standard Eight exams in parts of Rift Valley Nyanza and Coast provinces. On the same day, heavy rains triggered landslides in East Marakwet and Baringo Counties. About 50,000 families were put to danger while three people drowned in floods; (iv). On 13th November, heavy rains rendered the Marsabit-Moyale road impassable. During the same day, families were left out in the cold as landslides destroyed their homes in Kerio Valley and Elgeyo Marakwet; (v). In Muhoroni, , a woman drowned in raging River Makindu on November 14, 2011. On the same day, floods killed 2 people in Namanjalala, Trans Nzoia County. The Floods also displaced scores of people from the area. In Baringo and Marakwet Counties, two people lost their lives as a result of flooding; (vi). In Nairobi, heavy rains that occurred on 20th November paralyzed traffic in the City. Several motorists stowed overnight in the flooded streets. The heavy rains also led to power blackouts in various parts of Nairobi as power post that support transformers fell down; and (vii). In Kitale, delivery of maize to Kitale depot was delayed following the heavy rains that occurred in the area between 23rd and 24th November.

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6. FORECAST FOR DECEMBER 2011 This climate outlook for December 2011 is based on models developed from the expected evolution of global Sea Surface Temperatures (SSTs) and sea surface temperature gradients. The current warmer than average SSTs in western equatorial Indian Ocean as well as the weak La-Niña conditions in the Pacific were highly considered. The forecast indicates that the western half of the country is likely to continue experiencing enhanced rainfall in December 2011. Rainfall in the eastern sector is however likely to be slightly depressed (See figure 3).

The specific outlook for individual areas is as follows:

The Highlands West of the Rift Valley (Kitale, Kericho, Nandi, Eldoret, Kakamega), Lake Basin (Kisii, Kisumu, Busia), Central Rift Valley (, , Magadi), Northwestern regions (Lodwar, Lokichoggio, Lokitaung), central Highlands (, Muranga, , Embu, Meru, ), Nairobi area (Dagoretti, Wilson, Kabete, MAB) and parts of Northeastern (Marsabit) and Southeastern (, Makindu) are likely to receive near normal rainfall with a tendency to above normal (enhanced rainfall).

Most of the Northeastern (Moyale, Mandera, Wajir, Garissa), Southeastern Kenya (Voi, Taita, Taveta, Galole) and the the entire Coastal strip (Mombasa, Mtwapa, , Malindi, Msabaha, Lamu) are likely to experience near normal rainfall with a slight tendency to below normal (slightly depressed rainfall).

7. EXPECTED CESSATION Lake Basin, Western Highlands and Central Rift Valley,: Rainfall is expected to cease during the fourth week of December 2011 to the first week of January 2012. Northwestern and Northeastern: The cessation is expected in the first to second week of December; The Central Highlands, including Nairobi and the Southeastern lowlands: The rains will cease during the third to fourth week of December; The Coast strip: The rains will cease during the second to third week of December;

8. POTENTIAL IMPACTS

8.1 AGRICULTURE LIVESTOCK DEVELOPMENT AND FOOD SECURITY SECTORS Good crop performance will be maintained in the agricultural areas of central and southeastern Kenya. This will go a long way to improve the food security in the country. The rainfall is, however, likely to disrupt harvesting especially over the North-Rift areas.

Foliage and pasture conditions in the pastoral areas of Northern, Northwestern and Northeastern Kenya are expected to remain generally good despite the expected slightly depressed rainfall in some of these areas.

8.2 DISASTER MANAGEMENT SECTOR Flooding and land/mudslides are still likely to occur in the prone areas. Areas to watch out for flooding include the lower Tana, Kano plains in Nyanza and Budalang’i in , while landslides/ mudslides are still likely in Murang’a, Meru, Keiyo, Marakwet, Kakamega and Nandi Hills areas.

The expected heavy storms accompanied by lightning in Western Kenya, especially Kisii, Nandi, Kericho, Transmara and Kakamega are likely to cause havoc. The public is advised not to shelter under trees as this renders them vulnerable to the lightning strikes.

It is advisable not to drive in a severe storm accompanied by wind gusts and where visibility is impaired. In such events, it is imperative that motorists stop and wait for the storm to subside. Motorists are also advised not to drive their cars across streams where water is about 2 ft deep to avoid being washed away. Even in areas with seasonal streams care should be taken before crossing, as storm waters are strong. One should wait until the levels are low.

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8.3 WATER MANAGEMENT SECTOR Water levels in the reservoirs in the Seven Folks and Turkwel hydroelectric power generating dams are expected to rise significantly.

In the urban areas, authorities are advised to clear the drainage systems to avoid flooding in the cities. Communities are also encouraged to make use of various technologies available and harvest rainwater for present and futures use.

8.4 TRANSPORT AND PUBLIC SAFETY SECTOR The expected enhanced rainfall is likely to lead to muddy and slippery roads in parts of western, Nyanza, Rift Valley, North western and central Kenya. This may result in vehicles getting stuck and stalling in the muddy sections. Accidents may also occur as vehicles veer suddenly due to slippery conditions on the roads. Motorists are, therefore, advised to drive carefully in order to avoid such accidents that may emanate from the poor road conditions. In areas expected to have above-normal rainfall (enhanced rainfall), swelling of streams will cause water to overflow over bridges that were constructed without the use of meteorological data on return periods. This may affect roads especially in northwestern Kenya. Foggy conditions are expected on high ground areas of , Mt. Kenya region as well as Timboroa. The fog may affect visibility and hence motorists advised to drive with caution.

8.5 FISHERIES With warm SSTs over western Indian Ocean the wind patterns are likely to produce some turbulence. It is therefore expected that this will mix the upper layer of the ocean and bring up nurtients from below meaning increased fish catch.

8.6 HEALTH SECTOR The expected enhanced rainfall in western Kenya is likely to sustain the transmission of malaria in the counties of Kisii, Kakamega, areas in the Lake Basin and the highlands of Kericho and Nandi. The health sector should, therefore, ensure that the malaria drugs are readily available to avoid any loss of live.

N.B: This forecast should be used in conjunction with the daily 24-hour and the weekly forecasts issued by this Department.

DR. JOSEPH R. MUKABANA DIRECTOR OF METEOROLOGICAL SERVICES & PERMANENT REPRESENTATIVE OF KENYA WITH WMO

600 NOV LTM (NOV)

500

400

300

200 Rainfall (mm)

10 0

0

Stations Figure 1a: November 2011 Rainfall performance

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1000 TOT(ON) LTM(OND)

900 869.5

800 716.2

700 688.2

600 538.7 532.6 521.6 514.2 504.5

500 479.9 455.5 445.3 436.6 405.5 403.8 402.2 395.3 389.1 379.3 377.8

400 369.2 354.3 347.3 338.0 337.6 325.0 315.8 312.3 Rainfall in mm 310.4 307.1 298.6 297.5 297.0 296.0 289.9 289.0 287.6 283.7 278.5 277.3 268.9 263.3 300 262.8 261.5 261.2 246.1 239.0 236.4 233.9 231.5 220.5 216.6 212.9 205.0 193.1 188.0 184.6 180.8 177.2 200 171.5 160.4 154.6 147.3 139.0 130.7 115.5 100 41.8 0 VOI JKIA KISII LAMU EMBU MERU M.A.B. NYERI WAJIR KITALE NAROK KISUMU WILSON LAIKIPIA MALINDI MOYALE NAKURU MTWAPA GARISSA LODWAR KERICHO MAKINDU ELDORET MSABAHA MANDERA MARSABIT MOMBASA KAKAMEGA MACHAKOS DAGORETTI ELDORET AP Stations Figure 2a: October-December 2011 Seasonal Rainfall Performance

Figure 2b: % OND 2011 Rainfall Distribution Figure 1b: % November 2011 Rainfall Distribution

Figure 3: Rainfall outlook for December 2011

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