Mother Nature has been brutal this summer to a number of South West Pacific nations but it appears she may be about to spare populated places from devastation despite a large scale cyclone predicted to develop.

The models over the past 36 hours have been fairly consistent although the path has changed slightly, predicting it will track much faster to the south east.  Earlier it looked as though it would track slowly to the south south east.

Strength-wise it still appears it could be a category 3 tropical cyclone and may even briefly become a weak category 4 storm for a time.

WeatherWatch.co.nz forecasters believe the potential cyclone won’t have a direct impact on New Zealand weatherwise however the system is likely to track near enough to generate large swells over the upper North Island, from Northland to East Cape.

It’s important to note that these forecasts are based entirely on computer models, and while they have been very accurate this summer we simply can’t completely rely on them. 

Graphic : ECMWF map showing the deep low on Monday Feb 21.  The red shaded area is what we call the “cone of uncertainty”… meaning the severe weather could track anywhere inside that shaded area.  The black dot on the red line above the low is Nadi, Fiji.  The most likely track will be in the middle of the two bold red lines / WeatherWatch.co.nz

Our currently confidence of this predicted low becoming a tropical cyclone next week remains moderate to high.

FAQS
Will it still be as big as Yasi?   No, we believe the modelling over the past 50 hours shows it will be smaller in size but it still will be very powerful, potentially reaching Cat 3 or 4 strength.

Will it reach Category 5 strength?  Based on the current long range maps we don’t believe so.

Could it still hit land?  Definitely.  Remember we are still only looking at modelling on a system that hasn’t yet formed.  While the computers seem to be quite sure of this low forming, the path could change by several hundred kilometres this far out.  Thankfully the consistent message seems to be it will avoid all populated nations.

Could it turn and hit NZ?  Anything is possible with a cyclone north of us but all the long range models and the data we use at Weatherwatch.co.nz all indicate a large high in the Tasman Sea which will guide the cyclone well to the north east of us.

What countries are most at risk?  We think Fiji and Tonga.  The tropical low is expected to form east of New Caledonia and Vanuatu this weekend and rapidly deepen.  It’s possible it could bring heavy rain, thunderstorms and gales to New Caledonia and Vanuatu but at this stage it appears it won’t be very damaging.  Of course, we’d advise any readers from those two countries to keep up to date with their local government watches and warnings. 

Fiji, especially the Nadi side and southern side of the main island, will be at a heightened risk of severe gales as the low passes by early next week and it’s possible the storm may pass close to Tonga, however it may start to weaken as it moves further east.

Our next update on this potential storm will be on Friday.