''You have got very severe drought in three countries, some of the worst harvests on record in Swaziland and an incredibly high levels of HIV/AIDS in Lesotho,'' John Holmes, the UN humanitarian coordinator, told reporters.
''This is occurring on the basis of very vulnerable populations to start with,'' he said.
Carol Bellamy, the former director of UNICEF, the UN children's fund, in 2002 used the phrase ''perfect storm'' in relation to several southern Africa countries drought, environmental degradation, near starvation and AIDS sapping the strength of the working population.
Asked if the situation was approaching a ''perfect storm'' now, Holmes said, ''You could say that,'' because there there was a triple threat in all three countries, who have suffered from poverty for years.
In Swaziland, with only 1 million people, a third of all people between 15 and 49 are afflicted with HIV/AIDS. The harvest is the worst ever, prompting the government in June to declare a national disaster.
Holmes said that more than 400,000 people in Swaziland will require humanitarian assistance, and requested .6 million in emergency assistance.
Lesotho earlier this month declared a food emergency and an appeal will be issued shortly, Holmes said.
The tiny country has experienced the most severe drought in the last 30 years, which slashed the corn harvest by more than 40 percent. More than 400,000 people, or a fifth of the population, need emergency food aid.
In Zimbabwe, where diplomats blame some of the disaster on the policies of its leader, Robert Mugabe, about half of the financial appeals have been fulfilled.
An earlier appeal for 253 million dollars has drawn a response of 3 million with nearly 100 million dollars donated by the United States, Holmes said.