REPUBLIC OF KENYA
MINISTRY OF ENVIRONMENT AND MINERAL RESOURCES
KENYA METEOROLOGICAL DEPARTMENT
Dagoretti Corner, Ngong Road, P. O. Box 30259, Nairobi, Kenya,
Telephone: 254-20-3867880-5, Fax: 254-20-3876955 / 387373,
E-mail:director@meteo.go.ke, Website: http://www.meteo.go.ke
Ref. No. Met/ 7/23
Date: 30th March 2009
WEATHER REVIEW DURING MARCH 2009 AND THE OUTLOOK FOR
APRIL 2009
1.
SUMMARY
Generally sunny and dry weather conditions and higher than average temperatures prevailed over
most parts of the country in March 2009. A few areas in western Kenya (Kisii, Kakamega, Kisumu,
Kitale, Kericho), central Highlands and Nairobi (Nyeri, Meru, Embu, Dagoretti) and the Coastal strip
(Mtwapa, Mombasa) however recorded very light rainfall that was highly depressed for this time of
the year.
April is the peak month of the “Long Rains” season. The outlook for April 2009 indicates that most
parts of the country including the Central Rift Valley (Nakuru, Narok, Kajiado), Central Highlands
and Nairobi (Embu, Nyeri, Meru, Murang’a, Dagoretti), Southeastern districts (Machakos, Makindu,
Voi), Northwestern (Lodwar, Lokichoggio, Lokitaung), Northeastern Kenya (Mandera, Moyale,
Marsabit, Wajir, Garissa) and the Coastal Strip (Mombasa, Mtwapa, Malindi, Msabaha, Lamu) are
likely to experience generally depressed rainfall that will be characterised by poor distribution both in
time and space. The Western highlands (Kericho, Kitale, Kakamega, Eldoret, Kisumu, Kisii) are
expected to receive near normal rainfall with a slight tendency to above normal (slightly enhanced
rainfall).
The Western, Central, South-eastern and the Coastal areas are expected to experienced rainfall from
the beginning of the April. The rainfall will spread to the rest of the country from the second week of
the month.
2.
REVIEW OF THE WEATHER DURING MARCH 2009
Generally sunny and dry weather conditions characterized by high temperatures were dominant over
most parts of the country in March (up to 29th). However, a few areas in western Kenya (Kisii,
Kakamega, Kisumu, Kitale, Kericho), central Highlands including Nairobi (Nyeri, Meru, Embu,
Dagoretti) and the Coastal strip (Mtwapa, Mombasa) experienced light to moderate rainfall, which
was highly depressed and poorly distributed in time and space. This resulted from an unabated
prolonged delay in the onset of the “Long Rains” season over a number of areas. On 16th March, Kisii
station recorded the only rainfall storm during the month amounting to 81.8mm.
Up to 29th March, the Kisii station recorded the highest rainfall amount of 136.9mm (69%), as
compared to its Long-Term Mean (LTM) rainfall of 199.6mm. Kakamega, Nyeri, Meru, Kisumu,
Dagoretti Corner, Kericho, Embu, Mombasa, Mtwapa, Voi, Kitale, Narok, Moi Airbase and Thika
received just 68.5 (40%), 45.6 (58%), 31.8 (28%), 30.7 (19%), 29.4 (32%), 26.4 (15%), 20.6 (17%),
20.1 (36%), 19.8 (35%), 17.8 (21%) 15.9 (17%), 14.8 (15%), 12.4 (15%) and 11.4 mm (10%) as
compared to their respective LTMs of 172.0, 78.1, 115.2, 166.3, 92.8, 173.8, 119.7, 56.4, 56.2, 83.8,
93.1, 99.8, 83.9 and 110.7 mm, respectively.
The seasonal rainfall onset was generally delayed over most parts of the country with most stations
recording no rainfall at all throughout the period. The driest conditions occurred over the
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Northwestern, Northeastern and Southeastern regions where most stations recorded no rainfall at all
throughout the month.
Warmer than average Sea Surface Temperatures (SSTs) prevailed in the SW Indian Ocean (around
the Mozambique Channel as well as the Mascarene region) and Southern Atlantic Ocean adjacent to
the Namibian coast during the period. These temperature patterns significantly weakened the
pressures over these regions that normally pump moisture from the oceans into our country. At the
same time, relatively strong pressures were maintained over the Arabian Peninsula. This has kept the
rain-bearing system commonly known as the Inter-Tropical Convergence Zone (ITCZ) to the southern
parts of Tanzania, Northern Mozambique, and northern Zambia hence the dry conditions in the
country.
La Nińa like conditions also prevailed in the Pacific Ocean with cooler than normal sea surface
temperatures (SSTs) occurring over eastern and central equatorial Pacific. This also contributed to the
very poor rainfall conditions over the country.
3.
OBSERVED IMPACTS
The prolonged dry conditions due to lack of rainfall over the country impacted negatively on various
sectors:
 In the agricultural sector, most farming communities in the country were yet to plant by 26th
March 2009 due to the delayed onset of the seasonal rainfall;
 In the pastoral areas, there have been a few cases of animals dying following the prolonged
dry spell and poor and limited pasture conditions;
 Some perennial rivers have even dried up due to the huge rainfall deficits for consecutive
seasons; High temperatures and strong winds have been conducive for fast spread of wild fires
that have been occurring over various parts of the country;
 Dusty conditions and their associated health conditions such as allergic diseases have also
increased over most parts of the country; and
 Water scarcity has also led to the outbreak of cholera in the country.
4.
FORECAST FOR APRIL 2009
4.1
RAINFALL FORECAST
The rainfall forecast for April 2009 is based
on regression of Sea Surface Temperature
Anomalies (SSTAs) on Kenyan rainfall, Sea
Surface Temperature (SST) gradients and
the expected evolution of global SST
patterns. The forecast indicates that much of
the country is likely to receive depressed
during the month. Only the western parts of
the country are likely to receive slightly
enhanced rainfall during the month. This
will, however be poorly distributed in time
and space. The rainfall may be enhanced by
short-lived heavy storms that would be far
between. The specific outlooks for
individual areas are as follows:
The Western Highlands (Kitale, Kericho,
Nandi, Eldoret, Kakamega), Lake Basin
(Kisumu, Kisii, Busia) are likely to receive
near normal rainfall slightly tending to
FIGURE 1: RAINFALL OUTLOOK FOR APRIL 2009
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above normal (slightly enhanced rainfall) in April. The rainfall, would, however be poorly distributed
in time and space.
The Northwestern regions (Lodwar, Lokichoggio, Lokitaung), Central Rift Valley (Narok,
Nakuru, Naivasha), Highlands East of the Rift Valley (Nyeri, Embu, Meru, Murang’a,
Kiambu), Nairobi Area (Dagoretti, Wilson, Eastleigh), Northeastern Kenya (Garissa, Marsabit,
Wajir, Mandera, Moyale, Garbatulla), Southeastern Kenya (Machakos, Makindu, Voi) and the
Coast Strip (Mombasa, Malindi, Kilifi, Lamu) are likely to receive below normal (depressed)
rainfall in April (See figure 1).
4.2
PROBABLE ONSET
The western, central, southeastern and the coastal areas will start experiencing rainfall at the beginning of
April. The rainfall is expected to spread to the rest of the country in the second week of the month. The
rainfall is expected to be poorly distributed, both in time and space even in areas expected to receive enhanced
rainfall.
Flash floods emanating from sporadic rainfall may still occur in some areas despite the expected poor rainfall
performance over most parts of the country.
5.
EXPECTED IMPACTS
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Poor crop performance is expected in most parts of the country due to the expected poor
rainfall performance. Farmers are therefore advised to make use of fast maturing and drought
resistant varieties of crops. It is advisable that farmers work closely with the Ministry of
Agriculture to advice on the best agricultural practices to adopt given the late onset in the
“Long Rains” and potential shorter season even in the lower parts of western Kenya;
Pasture for livestock will continue to diminish in the pastoral areas due to the expected poor
rainfall performance. Pastoralists are advised to destock and remain with only strategic stocks.
Rehabilitation of watering points is also encouraged to avoid conflicts and civil insecurity that
is likely to emanate from water scarcity;
There are still chances of floods occurring in Nyando, Budalangi and Kano plains. Cases of
lightening strikes are also probable especially in western Kenya. Contingency measures should
therefore be put in place to avoid any loss of live and property;
The Seven-Folk power generating dams are expected to experience below normal inflows due
to the expected depressed rainfall in the catchment areas. The energy sector should therefore
strategize on hydroelectric power generation and distribution;
In areas forecasted to experience rainfall deficits, diseases related to poor sanitation and
especially cholera may be on the increase. The Ministry of Public Health is encouraged to map
possible outbreak areas and to intensify surveillance of such diseases.
NB: This forecast should be used in conjunction with regular updates issued by this Department.
Mr. V. Ahago
FOR: DIRECTOR OF METEOROLOGICAL SERVICES
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