By MetService Meteorologist Ciaran Doolin

Please note: all times listed below are New Zealand local time

History

Tropical Cyclone (TC) Winston was named by RSMC Nadi at 1pm on February 11th, located to the east of Vanuatu.  Since then, TC Winston has tracked south-southeast.

Meanwhile Tropical Cyclone Tatiana was named by the Australian Bureau of Meteorology on February 11th at 7pm, since then TC Tatiana has been moving southeast.

Historical track of TC Tatiana and TC Winston to 7am Saturday February 13th 2016.  Image via NOAA Earth System Research Laboratory.

Today

TC Winston was located between New Caledonia and Fiji (about 350 km northeast of Noumea or about 700 km southwest of Nadi) at 7am today (Saturday 13th February).  The central pressure of the cyclone was estimated to be 947 hPa , making it a Category 4 cyclone, and it was moving to the south at about 17 km/h.  Winds close to the centre of the cyclone were estimated to be around 175 km/h, and forecast to increase to 185 km/h by 1pm today.

TC Tatiana was located over the Coral Sea 1400 kilometres east of Townsville at 7.40am today (Saturday 13th February).  The central pressure of TC Tatiana was estimated to be 986 hPa, making it a Category 1 cyclone, and it was moving south at 15 km/h.  Winds close to the centre of the cyclone were expected to be around 85 km/h.

True colour satellite image showing the location of TC Tatiana and TC Winston at 9.40am Saturday 13th February.

Future track

TC Winston is expected to intensify slightly and turn more southeast over the next 24 hours. There is good agreement across the computer models for Winston to then turn northeast, away from New Zealand. Winston may then move towards southern Fiji, as shown in RSMC Nadi’s forecast track below.

Forecast track of TC Winston produced by RSMC Nadi in Fiji.

TC Tatiana is expected to gradually weaken to below TC strength over the next 24 hours, while remaining over the southern Coral Sea.

Forecast track of TC Tatiana produced by Bureau of Meteorology. (Note: times are in AEST.)

The graphic below shows a range of possible future tracks for both tropical cyclones based on data supplied by the UK Met Office. A majority of these have TC Winston moving south before turning northeast, and TC Tatiana is expected to continue south before turning north.

Range of possible future tracks for both tropical cyclones based on UKMO data.  Image from NOAA Earth System Research Laboratory.

Impact on NZ

There are currently no direct impacts expected for New Zealand as a majority of the models keep both cyclones well to the north of us. Indirect impacts could be an increase in swell for northern areas and easterly winds, neither of which are expected to be severe at this stage and MetService have no warnings associated with cyclones in place for New Zealand at present.

MetService meteorologists are monitoring both of these tropical cyclones closely and provide tropical updates daily via the Tropical Cyclone Activity page on metservice.com where you can also see hourly satellite imagery. 

With tropical cyclones there is always some uncertainly associated with the tracks they will take, so we advise people in New Zealand and planning travel to the Pacific to keep up to date with the latest forecasts and any severe weather warnings at http://metservice.com/warnings/severe-weather-warnings

We’ll post further updates on TC Winston and TC Tatiana in the coming days, and as always, you can keep up to date with the latest forecasts and warnings at metservice.com.