WEATHER: Colder SW flow for New Zealand may last 10 more days

07/06/2017

There's a chill in the air so far this June with heavy frosts in parts of the South Island and a big drop in temperatures for many parts of the North Island after what was a mild and wetter than average Autumn.

WeatherWatch.co.nz forecasters say the new winter pattern in June is seeing a lot of high pressure around south eastern Australia and at times extending into the Tasman Sea helping encourage a colder south west flow here in New Zealand.

"The larger the high pressure system is the bigger the reach it has, in other words it can help scoop up more cold air over the Southern Ocean and bring it up over New Zealand as a south to south west airflow" says head weather forecaster Philip Duncan.

"It looks like the next 10 days will see high pressure mostly stuck over the south eastern corner of Australia bringing a general sou'west flow to New Zealand during that several day period. This is quite different to a year ago when New Zealand was in a warmer than average trend" says Duncan.

In fact in June 2016 places like Napier reached stunning highs of up to 25 degrees. In the next 10 days the highest forecast high in Napier is 17 degrees, with a number of days only reaching 12 or 13 degrees.

In Southland and Otago a "real winter" has arrived since June kicked off with heavy frosts, hoar frosts and hail showers in recent days - mixed in with the sun too.  

Earlier Wednesday morning South Island frost specialist forecaster James Morrison, of WeatherStationtold WeatherWatch.co.nz that Pisa in Otago was -6 while Alexandra dropped to -5.1C this morning. 

More frosts are expected over the next couple of days across sheltered parts of the South Island.

Then we may see windier weather rolling in for a time (or off and on), especially for southern and eastern areas of the nation.  

There will be calm days in the mix too - and some regions may temporarily see different wind directions - but the general air flow across New Zealand for the next week and a half looks like cooler sou'westers, or southerly quarter.

While a colder pattern is remaining with us, bringing frosts, showers and even snow on the ranges and hills for a time, we currently don't see a big jump in severe weather. Keep up to date with our forecasts, news updates, weather maps and any Government warnings or severe weather outlooks from MetService.

For the most part it looks as though New Zealand is hugging the eastern edges of Australian based high pressure systems, so expect cooler southerly quarter winds (especially Sou'Westers) for the next week or so, with a mix of sunny and calm days, and showery, windy days.

Thanks again to the team at weatherwatch.co.nz for providing RadioLIVE with the latest weather information.