Hot February expects tropical cyclones [1]
Thursday, January 26, 2017 - 16:42
February is expected to be the month with the hottest temperature for Tonga and the most likely month for tropical cyclones.
The Director of Meteorology ‘Ofa Fa’anunu said that at the start of the 2016/17 cyclone season two to three cyclones were predicted to affect Tonga.
The current cyclone season began on 1 November, 2016 and runs through to the end of April this year.
He said this prediction was based on the sea surface temperatures patterns in the Pacific at the time. But so far no tropical cyclone activity has eventuated in the Southwest Pacific, although a total of eight tropical depressions have occurred since the season started.
"The main reason behind this unusual low tropical cyclone activity to date has been the presence of a persistent high pressure system over the central southern Pacific (over our area) at a height of 5-6km in the atmosphere which has suppressed deep convection (rising of warm air), which is a major driving force behind tropical cyclone formation."
This had also resulted in below average rainfall in Tongatapu and ‘Eua on the same period.
Mid-February
He said the next surge of tropical cyclone activity in the Southwest Pacific is likely to be from mid-February to mid-March as a surge of convective activity moves into the Pacific from the west.
Rainfall should also pick up around that time with the rainfall prediction for the next three-months for near normal rainfall.
'Ofa said this meant that because Tongatapu and ‘Eua are already experiencing meteorological drought conditions, rainfall sensitive sectors in both these islands should impose water restriction measures and execute plans for irrigation of farm plots, because of likely continuation of the dry conditions for at least another month.
In addition, temperatures have also been warm with the highest temperature on record for Tonga 35.5C was recorded in February 2016 at Niuafo’ou.
For Tongatapu in 2016, February also had the hottest day with 33.4C on February 18. The end of the year had a hot period, recording 32.7C on December 2.