A gale warning was upgraded to a storm warning for all Tongan coastal waters this afternoon, with heavy damaging northerly swell up to 4-6 metres, as an active trough continues to move slowly over Tonga.

The Fua'amotu Weather Forecasting Centre warned that extreme high tides at 8:50pm tonight would bring a heavy damaging swell, driven by storm force winds. Today's forecast high tide of 1.61m follows an exceptional spring tide at 1.70m (5.6ft) on Sunday, January 2.

“There is possible sea flooding in low lying coastal areas due to extreme high tide and heavy damaging swells.”

They forecast northeast winds 30-40 knots with momentary gusts up to 45-60 knots for all Tonga waters.

However, the wind is expected to gradually decrease by Wednesday evening to 15-25 knots, with moderate seas up to two metres.

NEMO

As the heavy storm set in, Tonga's National Emergency Management Committee met this morning with a joint task force for COVID management.

There were no reports of damage due to the storm. Some flooding in Neiafu, Vava'u, due to blocked drains was reported but did not require a national response.

Winds decreasing Wednesday

In their 1:00pm bulletin Fua'amotu WFC advised that a storm warning remains in force for and areas in Vava'u, Ha'apai, Tongatapu, 'Eua and Niuafo'ou land areas.

“Fresh to strong north to northeast winds with momentary gusts of up to gale to destructive storm force winds.”

The winds are expected to decrease tomorrow afternoon.

In the meantime, gale warning remains in force for Niuatoputapu land areas.

A heavy rain warning and flash flood advisory remains in force for all areas, except Niuas.

Tonga Meteorological  Services reported that the mean sea level pressure recorded at Fua'amotu Airport at 01:00pm was 1004.1 millibars and the relative humidity was 89%.

The maximum temperature forecast for today was 28C and the minimum for tonight 22C.

The next forecast from Fua'amotu Weather Centre is expected at 7:00pm, tonight.