Tuesday 2 July 2018
A ridge of high pressure becomes established over much of the country later today, and is expected to persist until late
Thursday, when a trough approaches the far south of the South Island. MetService meteorologist Andy Best commented
“Ahead of this trough, we expect northwesterly winds to develop from Thursday afternoon over the southern half of the
South Island. The northwesterlies are forecast to strengthen during Friday, and may reach severe gale from about Wanaka
southwards.” He went on to say that “Strong northwesterly winds are expected to spread over all of New Zealand on
Saturday, with rain and gales forecast for the lower half of the North Island.”
The strengthening northwesterly winds later in the week will make it feel warmer than normal for this time of the year –
in fact around 5-6 degrees warmer than usual. For example, here are selected forecast minima overnight Friday/Saturday,
Wainuiomata 12C, Paraparaumu 11C, Dunedin 9C, Blenheim and Christchurch both 8C and Invercargill 7C.
An active front moves onto the far south of the South Island late Friday. MetService severe weather meteorologists are
forecasting on Friday, a moderate confidence of rainfall accumulations meeting warning criteria in Fiordland, southern
Westland and the headwaters of the Canterbury and Otago lakes and rivers, the confidence increases to high on Saturday.
Note also the moderate confidence for Severe Northwest gales. This forecast will be reviewed and updated each day
leading into this event.
People planning to be in these areas on Friday and Saturday should monitor the development of this weather system via
the MetService website. In particular, check the Severe Weather Watches and Warnings pages of the site http://info.metraweather.com/e/60812/AllWarnings/fyzv2n/721448781and the Severe Weather outlook page http://info.metraweather.com/e/60812/SWOutlook/fyzv2q/721448781 for any updates.
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