Severe Tropical Cyclone Winston dropped a category overnight, as expected.  It is now a Category 4 Tropical Cyclone with sustained winds of 175km/h and gusts to 230km/h.

The central air pressure has risen considerably, from 915hPa on Saturday morning to 945hPa on Monday morning.

Winston’s westerly movement is slowing now too – down from 25km/h over the weekend to 13km/h this morning.  Today Winston will begin to curve south west then south towards the New Zealand direction.

Cyclone Winston is generating peak wave heights of 13 metres (42 feet) according to the Joint Typhoon Warning Center out of Hawaii.

As for Winston’s future – the cyclone is tracking towards northern New Zealand once again. In fact, the same belt of blocking high pressure remains around our part of the world which means we’re back to where we were 10 days ago, with Cyclone Winston tracking south towards us and the models conflicted over where it will precisely track.

Today’s thinking is that Winston may end up in the Tasman Sea by the end of this week, and then cross the North Island either this weekend or early next week.  The models have not been consistent with GFS modelling out of America pulling the storm more towards Australia, then eventually back to New Zealand via the Tasman Sea.

ECMWF modelling out of Europe shows Winston also tracking into the Tasman Sea but moving over the upper North Island in a weakened state.

Our confidence of Winston reaching New Zealand remains moderate – but it is expected to weaken significantly before reaching New Zealand.  In saying that, it may still bring severe weather.

We are more confident of dangerous beach conditions than severe weather from Winston at this very early stage – and as the week goes on we’ll have more confidence about whether or not the remants of Winston will actuall reach New Zealand…or perhaps spend another week north of the country still trying to make up it’s mind on if it will swing right, swing left or simply make up its mind and head south. 

– WeatherWatch.co.nz