Update Thursday 12th March at 5:30pm

JOHN LAW, METSERVICE METEOROLOGIST

The forecasting team continue to monitor the progression of Tropical Cyclone Pam. By comparing the forecast tracks of several models the team have compiled a best track forecast for the position of the centre of the system as it tracks southwards.

Using the most recent data the system is forecast to pass just to the east of East Cape during the Monday. However, there is still a large degree of uncertainty in the exact path of the cyclone and although the centre may not pass over New Zealand, Severe Weather is likely to affect parts of the country – especially the northeast of the North Island. Stay up to date with the latest warnings here: http://metservice.com/warnings/home

In the diagram below the best forecast positions are indicated by the red line while the surrounding grey envelope gives an idea of the spread in the tracks the cyclone could take. Adverse weather associated with the cyclone may spread much wider than this envelope of tracks. With still several days to go, the forecast is likely to change and the team will continue to bring you the latest information.

Forecast path of cyclone Pam Forecast track of Cyclone Pam shon in red, The surrounding grey envelopegives an idea of the spread in the tracks the cyclone could take.

The latest Severe Weather Outlook has been issued providing more information of severe weather forecast later in the weekend and into the early part of next week. Find out more at http://metservice.com/warnings/severe-weather-outlook

Find out more about what we mean by Severe Weather in this blog post: http://blog.metservice.com/2013/10/warnings-watches-and-outlooks/#

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Update Thursday 12th March at 11.00am

JOHN LAW, METSERVICE METEOROLOGIST

Tropical Cyclone Pam remains in the tropics and continues to intensify. Currently a category 4, which by definition has mean winds between 86 and 107 knots (157-198 km/h), the track of the system remains southward just to the east of the southern Solomon Islands and Vanuatu.

TC Pam position as at 10am 12 March 2015 TC Pam position as at 10am 12 March 2015

The latest forecast from the Fiji Meteorological Service is for the cyclone to become a category 5 (mean wind speeds in excess of 107 knots or 198 km/h) at around 7am on Friday 13th (New Zealand time); at this stage the forecast position is to the east of northern Vanuatu.

TC Pam track from Fiji Met Service

Staying in the tropics, Tropical Cyclone Nathan remains off the coast of Queensland and is joined by another Tropical Cyclone, Olwyn, which is off the coast of Western Australia and will not affect New Zealand. For more information about these cyclones, head to Australia’s Bureau of Meteorology website.

What are the impacts on New Zealand?

We are still several days away from the cyclone reaching New Zealand waters and there is still plenty of uncertainty in the models. Knowing where the system moves is important in calculating the severity of the impacts on New Zealand.

MetService’s forecasting team look at information from a selection of different global models which use equations to model the physical properties of the atmosphere. Here are the latest model outputs for 1pm on Monday 16th March:

Model outputs for 1pm on Monday 16th March

 

As you can see, the general consensus of the models is for the lowest pressure to stay off to the north and the east of the country – but that does not mean we will avoid getting some stronger winds, heavy rainfall and high seas with this feature.

For the very latest thoughts from MetService’s meteorologists, head over to the Severe Weather Outlook which is updated by 15:00 NZST every day.

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