THE EFFECTS OF EL NIÑO / LA-NIÑA

EPISODES IN KENYA

By

James K. Muhindi

Kenya Meteorological Department

P.O. Box 30259 – 00100

Nairobi, Kenya

Tel: 254-20-3867880

Mobile: 254-722-697801

E-mail: muhindi@meteo.go.ke

LAYOUT

1. Climatology of Kenya

2. Effects of El Niño / La Niña

3. Previous ENSO Years

4. Connection with Extreme Weather Events & Associated

Disasters

5. The 2015 El Niño as Compared to Previous El Niños

6. Indian Ocean Dipole

7. Impacts of Extreme Weather Events

8. Conclusion

ClimatologyMost parts of Kenya experience a bi-modal rainfall

pattern (two rainfall peaks in a year). The two seasons

are March-April-May (MAM) “Long-Rains” and

October-November-December (OND) “Short-Rains”.

The highest peak occurs in April.

The western parts of Kenya record significant amounts

of rainfall during June-July-August (JJA). The period

January-February is generally dry over most parts of the

Country. However, significant rainfall is occasionally

recorded during this period especially during El Niño

Episodes.

Bi-Modal Rainfall Pattern

0.0

20.0

40.0

60.0

80.0

100.0

120.0JA

N

FE

B

MA

R

AP

R

MA

Y

JU

N

JU

L

AU

G

SE

P

OC

T

NO

V

DE

C

RA

INF

AL

L IN

MM

MONTH

MEAN MONTHLTLY DISTRIBUTION OF RAINFALL AT GARISSA STATION

Tri-Modal Pattern

El Niño Episode• El Niño (The Baby Boy) is a term that refers to

anomalously warmer than average Sea Surface Temperatures (SSTs) in the eastern and central equatorial Pacific Ocean.

• These changes have important consequences over weather/climate around the globe, including East Africa.

• Every two to five years, El Niño reappears and lasts for several months or even a few years.

La Niña Episode

Scientists refer to the event when exceptionally cool

water lies off the coast of South America as La Niña or

"the baby girl."

Strong La Nina events have been responsible for the

opposite effects on climate as El Niño. For example, a

major La Niña event in 1988 caused significant

drought across North America and most parts of East

Africa.

Ocean areas correlated to OND rainfall in Kenya

The 1972 El Niño

The 1988 La Niña

Previous El Nino/La Nina Years

Previous El Nino/La Nina Years

2002

2006

2009

1998-2000

2007

2010

2012

Strongest El Niños

Strong El Niño events occurred in 1965-1966, 1982-

1983, and 1997-1998. They caused significant

flooding and damage from California to Mexico to

Chile. Effects of El Niño are felt as far away from

the Pacific Ocean as Eastern Africa including Kenya.

Strongest El Niños

Strong El Niños – 1957-58, 1965-66, 1972-73, 1982-83, 1997-98, 2015-16.

Strong La Niñas – 1955-56, 1973-74, 1975-76, 1988-89, 1998-2000.

Indian Ocean Dipole (IOD)

-ve IOD: – Normally

associated with depressed

rainfall in the country. This

may also lead to Drought

situation

+ve IOD: - Normally

associated with enhanced

rainfall in the country. This

may also lead to situation

serious Floods

IOD Index Time Series by 2015

Current Indian Ocean Dipole

Extreme Climate EventsExtreme Climate Events are events that highly

deviate from the normal occurrence. In terms of

rainfall, they normally occur in form highly enhanced

rainfall or lack of rainfall at all.

Most extreme climate events are associated with El

Niño and La Niña episodes. However, not all extreme

climate events are linked to the ENSO phenomena.

The highly enhanced rainfall of OND 1961 that

caused serious flooding occurred when ENSO

conditions in the Pacific Ocean were neutral.

Climate-related DisastersHighly enhanced rainfall is normally associated with

disasters such as:

-Floods

-Land-slides & Mud-slides

-Destruction of Infrastructure

-Outbreak of various water-borne diseases

-Loss of lives & Property among others

Disasters contn’dHighly depressed rainfall or lack of rainfall for a long

period is normally associated with disasters such as:

-Drought

-Food Insecurity

-Loss of Animal and Human lives

-Forest Fires

-Loss of lives & Property among others

Landslides in the Central Kenya region.

Flooding roads

Population Displacement

Flooding…

Damage to Infrastructure

Urban Flooding– Paved surfaces &

poor drainage

exacerbate flooding

in urban areas

The impacts of 1998/2000 droughts

on nomadic communities

Effects of Drought in Kenya

28

Hydro-electric power generation

dams in Kenya.

The 2015-2016 El Niño

2015 SST Anomalies in the Pacific

The 2015 El Nino The 1997 El Niño

OND15 Vs OND97 and OND-LTM

Current Global SSTAs

Current SSTAs in the Pacific

Probabilistic ENSO Outlook

65 percent chances of

ENSO Neutral and only 15

percent chances of El Niño

during OND 2017

ConclusionMost extreme climate events are associated with El-Niño/ La-Niña

episodes

The effects of El-Niño/ La-Niña are highly experience during

October- December (The peak season for both episodes)

It is important to keep statistics of extreme climate events for

mitigation purpose

Thank You for Your

Attention