The World Meteorological Organization predicts La Nina will continue through January and is expected to usher in drier and wetter conditions than normal in different parts of the world.
The latest seasonal forecasts indicate the La Nina event will cause drier than normal conditions in much of East Africa and lead to increased rainfall in southern Africa. Central Asia is likely to see below normal rainfall earlier than usual.
The WMO reports some of the Pacific islands and the northern region of South America will see some of the most significant precipitation anomalies associated with this year’s La Nina event — a cooling of ocean surface water along the Pacific coast of the South American tropics that occurs on average every two to seven years.
Some countries and regions are particularly vulnerable to changes in weather patterns.
WMO humanitarian expert Gavin Iley told VOA the Greater Horn of Africa was an area of particular concern.
“As we know, it is already being beset by problems, with locust infestation," Iley said. "And generally, the models are suggesting below normal rainfall for quite a large portion of the Greater Horn of Africa. So, obviously that could have a number of impacts … in areas like Somalia. … So, we always need to keep an eye on the latest outlook.”
WMO said governments can use weather forecasts to plan ways to reduce adverse impacts in climate-sensitive sectors like agriculture, health, water resources and disaster management.
WMO Deputy Director of Climate Services Maxx Dilley said governments can use La Nina forecasting to adapt their strategies to the changing weather patterns.
“You can imagine in the agricultural sector that some crops will do well under wet conditions and others will do better under dry conditions," Dilley said. "And there are agricultural management practices that can be adjusted to take account of whether it is expected to be wet or dry.”
Dilley said WMO increasingly is trying to tailor these forecasts to specific concerns, such as food security or human health. For example, he said, wet conditions alone do not provoke outbreaks of dengue fever or malaria. He said temperature, humidity and vegetation create the conditions for mosquitoes to breed.
So, rather than just giving a rainfall forecast, he said, meteorologists will provide a forecast that is correlated with these diseases and can be used for dengue fever or malaria control.