This year, weather patterns are being affected by the phenomenon known as El Nino. And while it may be centered in the tropical Pacific, it has far reaching implications for many countries, including those in Africa.
Dr. Gerry Bell, a meteorologist at NOAA, the National Oceanic and Atmospheric Administration, says, "El Nino is a periodic warming of the ocean temperatures over the eastern half of the Pacific Ocean, along the Equator."
"El Nino affects the weather patterns throughout the globe. Its biggest impacts are in theSome regions get more rain, others less. Some are warmer, some colder with more storms. The strength and number of hurricanes can be affected, as well as some African rain patterns.
"Historically, El Nino can affect the south African monsoon region. And that monsoon season goes from October through April. Typically, the south African monsoon is dryer than normal. In a moderate or strong El Nino, the dryness could become more severe," he says.
Mozambique and Madagascar, he says, are among the countries that could experience a decline in rainfall.
For equatorial eastern Africa, Bell says, "Rainfall tends to be enhanced during December, January and February, but what impacts that has on agriculture I really don't know."
The typical El Nino lasts about a year and the current one began in June.
"There's some uncertainty, but we're expecting this to most likely be a moderate strength event, as we start getting into November, December. Some of the computer models are suggesting it could be a strong event, but again, there's quite a bit of uncertainty in the forecast," Bell says.
Other regions affected
"Generally, the western tropical Pacific Ocean in Indonesia receives below normal rainfall during El Nino. And we're already seeing those below normal rains in place. At the same time, you tend to have above normal rainfall across the eastern half of the Pacific Ocean," he says.
The western coast of South America may also experience heavy rainfall and flooding.
"Right now, we're seeing El Nino helping to suppress the Atlantic hurricane season. That's good news for the United States…a little bit weaker season than some of these very strong ones we've been seeing in recent years," he says.
NOAA uses satellites, ocean buoys, ship reports and other means to track El Nino on a daily basis, if desired.