the weather outlook for november 2021 and the …
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REPUBLIC OF KENYA
MINISTRY OF ENVIRONMENT & FORESTRY
KENYA METEOROLOGICAL DEPARTMENT
Dagoretti Corner, Ngong Road, P. O. Box 30259, 00100 GPO, Nairobi, Kenya
Telephone: 254 (0) 20 3867880-7, 0724 255 153/4
E-mail: [email protected], [email protected]
Website: http://www.meteo.go.ke Twitter: @MeteoKenya
Ref. No. KMD/FCST/4-2021/MO/11 Date: 29th October, 2021
THE WEATHER OUTLOOK FOR NOVEMBER 2021 AND THE
WEATHER REVIEW FOR OCTOBER 2021
1. HIGHLIGHTS
1.1. The Weather Outlook for November 2021
November is normally the peak month for the October-November-December (OND)
“short-rains” season. The outlook for November 2021 indicates that the Lake Victoria
Basin, Highlands West of the Rift Valley and Central and South Rift Valley, and the
Highlands East of the Rift Valley, are likely to experience near-average rainfall for the
month. The South-eastern Lowlands, the North-Western, North-Eastern and the Coastal
Strip are likely to experience near-average to below average rainfall. Episodes of heavy
rains are likely to continue being experienced in several parts of the country during the
period.
1.2. The Weather Review for October 2021
Most parts of the country experienced dry weather conditions during the month of
October 2021 except the Highlands West of the Rift Valley, the Lake Victoria Basin, the
Central Rift Valley and few areas over the Highlands East of the Rift Valley where
occasional rainfall was experienced. The start of the seasonal rains (onset) has not yet
been realized over several places except the Western sector and few areas over the
Highlands East of the Rift Valley. Isolated storms were recorded over the Highlands
West of the Rift Valley, the Lake Victoria Basin, the Central Rift Valley and the
Highlands East of the Rift Valley as had been forecasted. Most meteorological stations
in the country recorded monthly rainfall totals of less than 75 percent of their October
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monthly LTMs. Nyahururu and Laikipia Air Base were the only meteorological stations
that recorded more than 125 percent of their October LTM.
1 THE WEATHER OUTLOOK FOR NOVEMBER 2021
The outlook for November 2021 is mainly based on empirical statistical models
developed from expected evolution of global Sea Surface Temperature (SST) anomalies
and the Southern Oscillation Index (SOI). The Equatorial sea surface temperatures
(SSTs) considered are below average across the central and east-central Pacific Ocean
which implies that La Niña conditions are present. This usually results to below
average rainfall over Kenya. Also considered is the Indian Ocean Dipole (IOD) which
is in the neutral phase and is likely to remain so in November.
1.1 Rainfall Forecast for November 2021
The forecast indicates that the Lake Victoria Basin, Highlands West of the Rift Valley
and Central and South Rift Valley, and the Highlands East of the Rift Valley are likely
to experience near-average rainfall for the month. The South-Eastern Lowlands,
Northwestern, Northeastern and the Coastal Strip are likely to experience near to
below average rainfall as shown in Figure 1. Episodes of heavy rains are likely to
continue being experienced in several parts of the country during the period.
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1.2 Outlook for Specific Areas
The Highlands West of the Rift Valley Counties (Trans Nzoia, Kericho,
Bomet, Nandi, Uasin Gishu, Elgeyo Marakwet, Kakamega, Vihiga, West Pokot,
Bungoma, Kisii, Nyamira); the Lake Victoria Basin (Kisumu, Homa Bay,
Migori, Siaya, Busia); the Southern and Central Rift Valley (Nakuru, Narok,
Baringo, parts of Kajiado, Laikipia); Significant amounts of rainfall are
expected throughout the month of November which are likely to be near the
long-term average for November. During this period, heavy storms are likely
to be more frequent especially in the afternoons and evenings.
North-western Counties (Turkana, Samburu): Occasional rainfall is
expected during the month of November 2021. The expected amounts of
rainfall are likely to be near to below the long- term average amounts for
November. Episodes of heavy rains accompanied by strong winds may occur
during the month.
Highlands East of the Rift Valley Counties and Nairobi County
(Nyandarua, Nyeri, Kirinyaga, Murang'a, Kiambu, Murang’a, Embu, Meru and
Tharaka Nithi and Nairobi) Morning rains and afternoon/evening showers are
expected over several places in the month of November 2021. The expected
total amounts are likely to be near the long-term average amounts for
November. Occasional episodes of heavy rainfall accompanied by strong winds
may occur during the month.
North-eastern Counties (Mandera, Garissa, Marsabit, Wajir and Isiolo):
Occasional rainfall is expected during the month of November 2021. The
expected amount of rainfall is likely to be below the long-term average for
November. Episodes of heavy rains accompanied by strong winds may occur
during the period.
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South-eastern Lowlands Counties (Parts of Kajiado, Kitui, Makueni,
Machakos and Taita Taveta): Occasional rainfall is expected during the month
of November 2021. The expected amount of rainfall is likely to be below the
long-term average amounts for November. The beginning of the month is likely
to have above average rainfall (wet spells) with rainfall amounts expected to
reduce as the month progresses. Episodes of heavy rains may occur during
the period.
The Coastal Strip Counties (Mombasa, Tana River, Kilifi, Lamu and Kwale):
Occasional rainfall along the Coastal strip is expected throughout the month
of November 2021. The expected amount of rainfall is likely to be below the
long-term average amounts for November.
1.3 Potential Impacts
The following are the likely impacts during the month of November 2021:
Agriculture and Food Security
The expected near average rainfall in the Lake Victoria Basin, the Highlands West of
the Rift Valley, Central and South Rift Valley and the Highlands East of the Rift Valley
is likely to provide sufficient soil moisture to sustain agricultural production. The
rains may however have a negative effect on post-harvest activities.
The depressed rainfall that is expected in the counties of Northeastern, Northwestern
and the South-eastern lowlands may slightly improve water and pasture for livestock
production and human use.
Disaster Management
Occasional flooding in low lying areas and along river basins in the Lake Victoria
Basin, as well as in areas surrounding the Rift Valley lakes may continue to be
experienced. Occasional flash floods are likely during this period. Flooding may be
experienced even in areas which may not necessarily be raining due to heavy rainfall
elsewhere.
In the Highlands West of the Rift Valley, where near average rainfall is expected,
lightning strikes are also highly probable, especially in Kisii, Kisumu, Nandi, Kericho,
Bungoma (Mt. Elgon areas) and Kakamega Counties. Cases of landslides/mudslides
in hilly areas of the Highlands West of the Rift Valley are also highly probable.
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In the Southeastern lowlands, Coastal region, Northwestern and Northeastern
counties, where mainly depressed rainfall is likely are expected, human to human
and human to wildlife conflicts are likely to be experienced due to competition for
diminished water resources and pasture.
Water Resources Management and Energy
The major river catchment areas for the country’s hydroelectric power generating
dams are expected to receive near average rainfall. The water levels in the dams
across the country are therefore likely to improve slightly. Water scarcity in most of
the ASAL areas is likely to continue being experienced. Thus, residents are advised
to harvest rain water for both human and livestock use.
Environment The expected rainfall during the month is expected to provide conducive soil moisture
for growing of trees especially over the western sector of the country including the
central and the Rift valley regions. The public should therefore take advantage of
these conditions and plant trees while putting in place measures to conserve the
environment.
Health In areas expected to receive near average rainfall, water-borne diseases such as
diarrhea are likely to emerge. Poorly drained areas may have pools of stagnant water
which may become breeding areas for disease-causing pathogens.
Transport and Public Safety Sector The expected rainfall may cause slippery roads in some parts of the country
increasing the risk of accidents. Flash floods may cause transport challenges
especially during rush hours and more so in areas where the roads become
impassable when it rains.
2 WEATHER REVIEW FOR OCTOBER 2021
2.1 Rainfall Review for October 2021
The month of October marks the onset of the October-November-December (OND)
short-rains season in Kenya. The start of the seasonal rains (onset) has not yet been
realized over several places except over the Highlands West of the Rift Valley, the Lake
Victoria Basin, Central Rift Valley and few areas over the Highlands East of the Rift
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Valley where the onset has been realized. Isolated storms were recorded over the
Highlands West of the Rift Valley, the Lake Victoria Basin, the Central Rift Valley and
the Highlands East of the Rift Valley. For instance, Kimunye rainfall station in
Kirinyaga County recorded 65.7mm in 24 hours on 19th October while on 20th October
Kangaita Tea Research rainfall station also in Kirinyaga County recorded 52.0mm.
Other stations that recorded heavy rainfall include Eluuya secondary school in
Bungoma County that recorded 49.3mm on 1st October, Nyeri that recorded 46.2mm
on 26th October and Kisumu that recorded 40.0mm on 3rd October.
Most meteorological stations in the country recorded monthly rainfall totals of less
than 75 percent of their October monthly LTMs (depressed rainfall). Nyahururu and
Laikipia Air Base were the only meteorological stations that recorded more than 125
percent of their October LTM. The stations recorded 172% and 156.9% of their
monthly LTMs respectively.
Up to 28th of October, the highest monthly rainfall total of 188.3mm (108.9% of the
LTM) was recorded at Kericho Meteorological Station. Other stations that recorded
more than 100mm of rainfall include Kisii, Kitale, Laikipia Air Base, Nyahururu, Meru
and Kisumu that recorded 176.2mm (97.6%), 159.8mm (124.5%), 116.1mm
(156.9%), 106.2mm (172%), 105.9mm (45.6%) and 103.1mm (107.3% respectively.
Embu, Kakamega, Eldoret, Nyeri, Dagoretti and Nakuru recorded 82.2mm (46.5%),
79.5mm (48.6%), 71.7mm (114.7%), 70.4mm (61.7%), 70.1mm (115.2%) and 59.3mm
(70.5%) respectively. The rest of the stations recorded less than 50mm with Machakos
recording no rainfall at all throughout the month. as depicted in Figures 2a and 2b.
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Figure 2a: October 2021 Rainfall Totals Against October LTMs
0
50
100
150
200
250
LO
DW
AR
MA
RSA
BIT
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INF
ALL I
N M
M
STATIONS
OCTOBER 2021 RAINFALL TOTALS AGAINST OCTOBER LTMS
OCT-TOT OCT- LTM
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Figure 2b: October 2021 Rainfall Totals Against October LTMs
Listed below are rainfall reports from voluntary rainfall stations elsewhere in the
country that recorded more than 100mm in October 2021.
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Station Amount In
mm Station
Amount
In mm Station
Amount
In mm
NYAMIRA D.O. 235.1 KIBABII UNIVERSITY 136.3 KANGAITA TEA
RESEARCH 114.3
KANDUYI
AGRICULTURAL
OFFICE
217.6 KAPLAMAI CHIEF’S OFFICE
128.0 MAINEK TORO
SECONDARY SCHOOL 104.5
KANGEMA 203.1 CASTLE FOREST
STATION 126.8
BUNGOMA WATER
SUPPLY 183.5 GAKOE TEA ESTATE 126.5
MAKWA COFFEE ESTATE
103.7
ELUUYA GIRLS
SECONDARY SCHOOL 176.8 MUKAKULA FARM 126.3
KANGAITA FOREST STATION
103.3
NABICHAKHA
SECONDARY SCHOOL 173.1 KANGAITA TEA FARM 123.5
KHALABA WARD 166.6 ADC NAMANDALA 122.8
KAIBOS MIXED SECONDARY
164.1 WRA KAPENGURIA 122.0
BUTERE 164.0
KAPSOKWONY
AGRICULTURAL OFFICE
121.0
ST CLARE GEKENDO AWS
163.5 COFFEE RESEARCH INSTITUTE KITALE
111.8
BUMULA AGRICULTURAL
OFFICE 140.3 ADC JAPATA 115.7
2.2 Rainfall Review for OND 2021 Season
Further analysis of the OND 2021 season indicates that the rainfall amounts
recorded at all the meteorological stations across the country during the month of
October 2021 are yet to reach the seasonal LTMs. The highest percentage of 62.4%
was recorded at Laikipia Air Base meteorological station with 116.1mm against the
seasonal LTM of 186.1mm.
Stations that recorded seasonal rainfall total of more than 100mm include Kericho
188.3mm (42.9%), Kisii 176.2mm (35.2%), Kitale 159.8mm (60.9%), Nyahururu
106.2mm (58.2%), Meru 105.9mm (15.3%) and Kisumu 103.1mm (31.4%). This
implies that no station has attained near-average rainfall (between 75 and 125
percent of their seasonal LTMs). Marsabit recorded less than 1mm of rainfall while
Machakos recorded no rainfall at all during the month of October 2021.
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Figure 3: OND 2021 Rainfall Totals against OND Seasonal Totals
2.3 Experienced Impacts in October 2021
Agriculture and Food Security
The continued dry conditions over the ASAL areas have led to insufficient pasture
and water for livestock and food for human consumption. More livestock deaths
were reported in Isiolo, Kilifi, Samburu and Tana River Counties. The prices of
livestock in these Counties have gone down as they are in bad condition. In Isiolo
County, more than 55% of the people are in dire need of food and children are
severely malnourished and have to rely on food supplements.
Heavy rainfall experienced in TransNzoia County affected harvesting, drying and
storing of grains.
Disaster Management
Drought has been reported in more than twenty three Counties where residents
are faced with acute food shortage.
There was a case of human wildlife conflict in Samburu County where an elderly
man was killed by a rogue elephant.
Heavy rainfall accompanied by strong winds destroyed farms, houses and school
roofs in Kisii, Elgeyo Marakwet and TransNzoia counties.
0
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LOD
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IN M
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STATIONS
OND 2021 RAINFALL TOTALS AGAINST OND SEASONAL LTMS
0ND-TOT OND- LTM
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Water Resources Management and Energy Most water sources in Isiolo and Tanariver Counties have dried up and
pastoralists have to walk for long distances daily in search of water both for
human and livestock consumption.
Transport and Public Safety Transport was temporarily disrupted along the Njabini- Engineer and Pesi roads
in Nyandarua County on 1st October following heavy rainfall that was
accompanied by hailstones in the area.
NB: This outlook should be used together with the 24-hour, 5-day, 7-day,
monthly, special forecasts and regular updates/advisories issued by this
Department as well as Weekly and Monthly County forecasts developed and
availed by County Meteorological Offices.
Stella Aura, MBS
DIRECTOR OF METEOROLOGICAL SERVICES