A cool and windy blast of weather is heading towards the South Island and lower North Island this coming Friday and weekend say WeatherWatch.co.nz forecasters.

While this week will have cooler weather for many regions than last week, the colder shot of air arriving around Friday and Saturday appears at this stage to be more potent.  “Again, we’re not warning of a major wintry blast but certainly a cold snap for the deep south especially” says head weather analyst Philip Duncan.

Talking on Country99TV on Monday Mr Duncan said farmers should be aware of it but it does look short lived.  “We’re heading out of the main risk zone for lambing and this cold snap looks very short lived, but still one that farmers and growers should monitor” he told viewers.  “We may also have a few frosts next week if a high comes in behind it. So while not high risk there is still some risk worth monitoring as we slowly ease ourselves out of winter and towards summer”.

WeatherWatch.co.nz expects parts of Southland and Otago to fail to reach double digits on Saturday and any double digit highs are likely to only reach 10 to 12 degrees.

However once you get east of the ranges it’s a different story, and while cooler conditions are expected the strong winds will likely keep temperatures around normal for October  “Eastern parts of the South Island, like Christchurch, will likely get a brief southerly change but generally speaking the winds will be from the west or south west which is much drier and warmer than a south or south east wind”.

Windy weather is expected to dominate some parts of New Zealand this week – especially at the end of the week when a very large high over southern and eastern Australia competes with a very large low in the Southern Ocean.  The result being windy and changeable weather for New Zealand.

Air pressure in the Southern Ocean could go as low as 955hPa while the high over South Australia is getting closer to 1040hPa. 

It’s this huge difference in air pressure over a fairly short distance which creates the strong winds over New Zealand.

A high next week may cross over the southern Tasman Sea and then the South Island – potentially bringing frosts.

The government forecaster, MetService, says they have some confidence of severe gales this Friday and Saturday for Southland, Otago, Canterbury, Marlborough, Wellington, Wairarapa and Hawkes Bay and a moderate risk for rain warnings along the entire West Coast of the South Island.

WeatherWatch.co.nz will continue to monitor over the coming days.

– Homepage image / Wellington’s Zephyrometer Sam Hall

– WeatherWatch.co.nz