Cyclone to hit New Zealand

  • Beach goers will be well advised to avoid the coast this weekend (Photo: Ben Birchall/PA Archive/Press Association Images)

    Model comparison for lunchtime on Saturday local time

    Model comparison for lunchtime on Sunday local time

  • Cyclone to hit New Zealand
    13.03.2014 15:32

    Autumn in the southern hemisphere has kicked off on a very stormy note across New Zealand with one storm having already wreaked havoc in the first week of March. Described as a ‘100-year event’, the city of Christchurch was hit particularly hard with around 100 homes reported to have been flooded.

    With little more than a week’s respite, another storm system is forecast to hit New Zealand over the coming weekend. Tropical Cyclone Lusi formed over the Equatorial Pacific earlier this week and has already brought gale force winds and heavy rain to the Republic of Vanuatu. Currently a Category 3 storm, the cyclone continued to deepen as it tracked east-south-eastwards over the relatively open waters of the archipelago.

    A Category 3 storm means than sustained wind speeds are exceeding 119 km/h, with forecasts showing that wind speeds could potentially reach 130 km/h at the storm’s peak.

    A number of atmospheric processes have led to a favourable environment for the storm to strengthen and take the southward path it is expected to. Low wind shear (5-10 kts) has helped to provide the ideal conditions for the cyclone to develop, while a building upper ridge to the east of New Zealand will encourage the storm to take a southward path. Unfortunately for residents of New Zealand, this currently means the eye of the storm will pass very close to the western coastline of North Island on Saturday, bringing heavy rain and potentially destructive winds, before hitting South Island on Sunday.

    Despite initial uncertainties over the exact track of the storm system, forecast models are now in good agreement regarding the position of the eye on Saturday lunchtime and again on Sunday lunchtime, (both local time) (see images). Severe weather warnings are expected to be issued on Friday, with torrential rain and severe gales likely to affect wide areas.

    Cyclone Lusi is expected to weaken by the start of next week, as it continues its southward track towards Antarctica. This will allow for a spell of much drier and more settled weather in the ensuing days, no doubt coming as welcome news to New Zealanders.

    By: John Lee