The development has seen several officials in Southern African countries gearing up for the rainy season which normally goes on until the end of March 2011. But this year, with the La Niña influence, the region is bracing for a wetter than usual season, IRIN reports.

Heavy rain brought on by the lingering effect of La Niña in 2009 caused the worst floods to hit Namibia in four decades, and extensive damage in Zambia estimated at several million US dollars.

La Niña is characterized by unusually cold ocean temperatures in the eastern equatorial Pacific Ocean, whereas El NiÃo is associated with warmer than normal water temperatures, according to the US government's National Oceanic and Atmospheric Administration (NOAA).

"Both of these climate phenomena, which typically occur every 2-5 years, influence weather patterns throughout the world and often lead to extreme weather events," said NOAA, which has indicated in its latest update that this year's La Niña has strengthened further.

The phenomena are called El Niño/La Niña-Southern Oscillation, or ENSO. La Niña is usually associated with more rain in Southern Africa, but it is very difficult to predict the impact, as this could vary within the African region and from one La Niña event to another, say scientists such as Cobus Olivier with the prediction research section of the South African Weather Service.

But based on the latest update on ENSO, there is a strong chance that many parts of the region could be in for above-normal rains, Olivier said.

Southern Zambia, Malawi and Madagascar, central and southern Mozambique and parts of Namibia, Botswana, Zimbabwe and South Africa are in for more rain than usual.

"But we are also expecting dry spells in some parts of Malawi," said James Chiusiwa, coordinator of Malawi's Department of Disaster Management Affairs. His department has begun holding contingency planning meetings with different government and aid agencies.

"We are trying to ensure we have enough stocks of emergency relief items," he added.

Floods in early January of 2006 displaced about 40,000 people in Malawi's southern Chikhwawa District along the River Shire, FEWS-NET noted in its latest update on Malawi. People in the district are recovering from a dry spell and food shortages this year. Floods could disrupt a food assistance programme under way in the area, said FEWS-NET.

Last week strong rains destroyed property in the commercial City of Blantyre and the lakeshore tourism District of Mangochi. Residents fear for the worse. Chikhwawa and Nsanje Districts in the Lower Shire are heavily affected by floods each year.

Possible floods in Mozambique's southern provinces of Inhambane and Gaza could affect food supplies, and people could require aid. Just over 200,000 people are already in need of food aid ahead of the next harvest in March 2011 in the two provinces.

Mozambique is vulnerable to floods and droughts, but has significantly improved its early warning systems and response to extreme natural events.

Many aid agencies cite Mozambique as a role model for other developing countries for its disaster preparedness strategy. Jorge Uamusse, Mozambique Red Cross Society's disaster management head, said: "The government invests a lot in disaster preparedness. It holds at least two flood simulation exercises for vulnerable communities living along the rivers, without fail, every year."

There is need to pre-position emergency supplies. Many countries have already begun to pre-position supplies of relief items and food to prevent shortages.

Zambia's Dominicano Mulenga, national coordinator of Zambia's Disaster Management and Mitigation Unit, said: "Based on our past experience, we know four provinces [out of nine] and 36 districts [out of 72] will be affected, and we have positioned stocks of maize in those areas."

Mozambique's Uamusse said the Red Cross had positioned relief items in warehouses all along the River Zambezi in central Mozambique.

Reinforcing river embankments is an expensive exercise, said Mulenga.

"We are rather concentrating on improving our early warning." The Zambian government is supplying members of communities along the Zambezi with mobile phones to SMS information on water levels to the authorities. "The idea is to supply the phones throughout the country as we get deeper into the rainy season."

FEWS-NET, in its latest update on Zambia, said the government had yet to relocate people affected by the 2009 floods. Flooding is an annual event in Zambia, "but we are still trying to improve our response," said Mulenga.