Dry weather forecast may lead to possible El Nino developing in 2017 [1]
Tuesday, May 16, 2017 - 18:25
Forecasts of drier conditions in the second half of 2017 may lead to the development of an El Nino climate cycle says Tonga's Department of Meteorology (MET).
An El Nino develops when the sea surface water temperature is warmer than normal, causing a lower than normal rainfall and an increase in cyclones. However, MET says that although there is a 50% chance of El Nino developing, the El Nino - South Oscillation (ENSO) remains neutral.
Sea surface temperatures have warmed in the central and eastern parts of the Pacific Ocean since the start of the year and are now 0.5C warmer than average but still +0.8C below the El Nino threshold level.
For the next three to six months, MET's forecast is for drier conditions.
MET also advises that “dry conditions are usually experienced during the onset of an El Nino” and encourages the public to use water wisely and collect as much as possible when it rains.
According to MET's Table 1 picture above, Vava’u is expected to experience drier than normal conditions for the next six months from June to November.
Niuatoputapu is expected to experience drier than normal conditions in the next three months June – August and Ha’apai is expected to experience drier than normal conditions in September – November.
Normal conditions are forecast for Niuafo’ou and Tongatapu for the next six months.
In the last three months, rainfall was above average across all of the island groups of Tonga.