One to three tropical cyclones are expected to affect Vanuatu in the 2017 to 2018 cyclone season with a slight chance that one could be severe (category 4), according to the Vanuatu Meteorology and Geohazards Department (VMGD).
The 2017 to 2018 cyclone season begins next month (November) and will end April next year. All communities are advised to remain alert and prepared throughout this period of six months.
The peak time for the occurrence of tropical cyclones in Vanuatu is during the months of December to February but highest in January.
Vanuatu experienced two tropical cyclones, TC Donna (May) and TC Cook (April) during the past season.
The 2016 to 2017 South Pacific tropical cyclone season was the least active since 2011- 12, and one of the quietest on record with only four cyclones occurring east of 160°E, according to VMGD.
On record, 116 cyclones have affected Vanuatu from 1969 to 1970 seasons to 2009 to 2010. These cyclones have passed within a 500km of Port Vila.
Vanuatu is located in the hotspot of tropical cyclone activity in the region.
Each year Vanuatu and New Caledonia experience the greatest cyclone activity with at least 2-3 cyclones passing close to their vicinity.
The increasing sea temperatures in the western Pacific region associated with weak La Niña signs would greatly influence the occurrence of tropical cyclones in Vanuatu, VMGD explained.
“Near La Niña conditions are likely to affect Vanuatu towards the end of 2017 with resulting impacts on rainfall (extreme rainfall and strong winds) that can affect livelihoods.
“Near La Niña conditions were present in late 2016 and in late February 2017, some international climate models surveyed by VMGD favored El Niño conditions from June.
“While an El Niño did not eventuate and remained within ENSO neutral, warmer than normal central and eastern Pacific sea surface temperatures enhanced and shifted the South Pacific Convergence Zone north eastward generally from about May to September.
“This resulted in below normal rainfall throughout Vanuatu.”
Meanwhile, near normal to above normal rainfall is expected for Vanuatu in the next three months, November to January with more than 200mm forecasted for the southern region (Shefa and Tafea), and more than 400mm of rainfall for the northern region Malampa, Penama and Sanma) with the exception of Samna expecting more than 1000mm of rainfall.
SOURCE: VANUATU DAILY POST