UN: La Niña weather pattern likely to last for some months
The current La Niña weather pattern is expected to strengthen and continue through the middle of the year, bringing wetter conditions to Australia and the western Pacific and a drier climate to the Americas, the, United Nations World Meteorological Agency (WMO) announced.
The WMO stated its latest La Niña forecast -– which began in the third quarter of 2007 -– has picked up strength in the past three months, with sea surface temperatures now about 1.5 to 2 degrees Celsius, colder than average over large parts of the eastern and central equatorial Pacific Ocean.
"This La Niña is in the mid-range of past historically recorded events, but the slight further cooling in recent months will likely place it on the stronger side of the middle range," the agency said.
During a La Niña pattern, the cooler sea surface temperatures in the eastern Pacific shapes weather conditions across much of the world: heavy rain and thunderstorms, for example, become much more frequent in the western Pacific. It is the opposite of the El Niño phenomenon, which is considered to have ended its current cycle last year.
Prisco Nilo, director of the Philippine Atmospheric Geophysical and Astronomical Services Administration meanwhile warned that rains caused by the active monsoon season could contribute to the rise of dengue, as well as viral and water-borne illnesses.
The recent dengue surveillance update of the Health department's National Epidemiological Centre (NEC) revealed a 190 percent increase in the number of dengue cases recorded from January 1-25 with 656 cases compared to last year's 226 cases within the same period.
Apart from dengue, influenza, leptospirosis and water-borne diseases such as diarrhea are also common during this season.
La Niña is set to peak February until March, and will gradually decline thereafter, the Pagasa said. (PNA)