•But WMO cautioned it may not necessarily lead to drought in East Africa.
•The East Africa’s weather is also influenced by the Indian Ocean Dipole, which can cause heavy rains or dry weather.
Image: FILE
The El Niño event, which brought heavy rains into Kenya, is likely to be replaced by La Niña conditions later this year, according to a new weather update.
La Niña’s impact around the world varies widely by geographic location. For Kenya, it causes dry conditions during the short rainy season from October.
It was largely blamed for the multi-year drought that hit Kenya between 2020 to 2023.
The new forecast was issued by the World Meteorological Organisation (WMO), saying the probability of a La Niña is growing rapidly.
“The chance of La Niña conditions increases to 60 per cent during July-September and 70 per cent during August-November,” WMO said in a statement.
In many locations, especially in the tropics, La Niña produces the opposite climate impacts to El Niño.
But WMO cautioned it may not necessarily lead to drought in East Africa.
It said the effects of each La Niña event vary depending on the intensity, duration, time of year when it develops and the interaction with other modes of climate variability.
The East Africa’s weather is also influenced by the Indian Ocean Dipole, which can cause heavy rains or dry weather.
"La Niña conditions generally follow strong El Niño events and this is in line with recent model predictions, although high uncertainty remains regarding its strength or duration,” said Ko Barrett, the WMO deputy secretary.
La Niña refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean.
The Kenya Meteorological Department did not comment on the WMO update, which is made by synthesising weather models from different regions.
However, KMD noted that June-August will still be wetter than average in Kenya.
“The outlook for the June-July-August 2024 rainfall season indicates likelihood of above-average rainfall for the highlands west of the Rift Valley, Lake Victoria basin region, the Rift Valley, parts of the highlands east of the Rift Valley and the northwestern region,” Met director David Gikungu said.
The coastal strip is expected to receive near to above average rainfall, while Central highlands and Nairobi areas, as well as parts of Ukambani will experience cool and cloudy conditions with occasional light to moderate rainfall until August.
“Overall, temperatures across the country are expected to be slightly warmer than average for the season,” he said.
This season is usually the coldest in Kenya.
Gikungu said although it will be warmer this year, cool weather will start drifting in this week.
“Intermittent cold and cloudy conditions are expected over some parts the highlands east and west of the Rift Valley, the southeastern lowlands and the Rift Valley,” he said.
This region covers Nyandarua, Laikipia, Nyeri, Kirinyaga, Murang'a, Kiambu, Meru, Embu, Tharaka, Nairobi and Ukambani.
He said most parts of the country are likely to be generally dry this week. However, afternoon rainfall is still expected over a few areas around Lake Victoria this week.
Between March and April 2024, extreme rain caused devastating floods in several countries of East Africa.
The rainfall led to rivers overflowing and landslides in highland regions, affecting more than 750,000 people and displacing hundreds of thousands.
At least 300 people died in Kenya and 155 in Tanzania.
Much of the impact was in large and highly populated cities, particularly the informal settlements of Nairobi.
Across the region, the downpours killed 4,000 livestock and destroyed 27,000 acres of crops.
These new floods take place against the backdrop of a three-year-long drought. The region was still recovering from another extreme rainfall episode in October-November 2023.