Occasional frost occurrence is common in the high altitudes of PNG, particularly Tambul, Kandep, Upper Mendi, Ialibu and few other pockets in the highlands.
Frost in PNG is often associated with drought. During the 2015 El Nino drought, frost occurred in Tambul – not once but over five consecutive nights in August, destroying all sweet potato crops. It occurred again twice in September.
According to the PNG National Weather Service, it was the strongest event since 1997.
In a climate outlook released on September 4, NWS reported that: “The impacts of this El Niño event is a true testament of the severity of this phenomenon now being felt in all parts of the country.”
The high altitude highlands has been the worst affected, as noted by the Highlands Drought Response Team’s recent assessment.
“One interesting observation which confirms this event to be the strongest El Niño event ever is that unlike the past El Niños, the magnitude of the real extent of the damage was very huge, encroaching into areas which were once immune to frosts and droughts,” says Kasis Inape of NWS, who was part of the team to the highlands in late August.
Areas such as Tambul received category 5 ranking – as the worst due to the double impact of El Niño induced drought and frost.
“The typical cycle of an El Niño is that it gets organized in Autumn (FMA), matures around Spring (ASO) and dissipates the following Autumn.
“The current El Niño has now matured and slowly it will dissipate. Normally, during a very strong El Niño event, the drought is often broken by heavy floods in Autumn therefore there is this added precaution to be wary of after the drought.”
To date, the high altitudes are yet to fully cover from the staple food – sweet potato.
Generally all highlands provinces were affected by drought.