Large area of low pressure feeds a stream of rough weather across western and northern parts of the country. Image: weather.com

Government forecaster MetService has just issued a number of snow warnings for New Zealand.  Weather ambassador Bob McDavitt says a Severe Weather Warning has been issued for heavy snow to work its way northwards from Fiordland into Westland, Buller and north-western
parts of Nelson late today and onto the central North Island during Friday.

Mr McDavitt added that it is uncommon for MetService to issue a heavy
snow warning for Westland, Buller or northwest Nelson. “This snow may fall in a few places not used to it, so travellers should check road conditions…and be prepared to alter their plans if necessary”.

Since midnight last night 4900 lightning strikes have been detected by the Weather Watch Centre’s lightning radar, most occurring out in the Tasman Sea.  An active front is moving up the West Coast and should reach Taranaki this evening and Auckland overnight bringing with it thunderstorms, squalls, hail and winds to gale force for a time.

Overnight and during today large showers, some with thunder and hail have moved across western regions from Taranaki to Northland.  The stormy weather overnight has marked the beginning of several days of rough weather as a low pressure system engulfs New Zealand. 

Several fronts are set to bring more of the wet stuff to northern New Zealand meaning yet another wet weekend is on the cards for many. Head weather analyst Philip Duncan says because the low is so big it will stick around until at next week. “Most winter storms race through very quickly, lasting only a few days but because there is such a large pool of low pressure this one will take several days to fully clear the country”.

Mr Duncan says while the low is extreme in size it’s definitely not at the extreme end as far as severe weather is concerned. “Yes it’s rare that we’re seeing such a large area of low pressure but that simply means we’re in for a number of wet and windy days rather than just one short, sharp blast”

He says because the low air pressure is spread over a large area the intensity is decreased.

MetService, who said today the storm is “nothing extraordinary”, has issued a number of watches in its Severe Weather Outlook which includes a moderate risk of heavy rain for the West Coast, Tararua Ranges, Mt Taranaki and Central Plateau hills and ranges, and a low risk of severe gales from coastal Marlborough right up the east coast to East Cape and then from northern Coromandel to Northland and a risk for heavy snow about Southland.

They expect strong to gale force winds in a number of regions tomorrow including Auckland, Gisborne, Napier, Masterton and Wellington, snow on the hills around Dunedin and have this morning increased the risk for thunderstorms right along New Zealand’s western coastline to ‘high’ which will include small hail and possible weak tornadoes.

“Today we’ll see showers moving in from the west, some will be thundery across the Taranaki region and some other western parts. Winds from the north west will pick up considerably today and tonight with more rain and isolated thunderstorms moving in” says Duncan.

During Friday more rain or showers will spread across western areas of both islands with heavy falls expected in the ranges.  Some snow is also likely about Southland as temperatures drop.  Eastern areas of the South Island are expected to be relatively sunny and calm due to the sheltering effect of the Southern Alps.

On Saturday yet more heavy showers will spread across the nation’s west coast possibly cancelling more children’s sports.

Meanwhile Sunday will see the low starting to move out into the Pacific but should flick a weak cold front up the South Island’s east coast. “There’s nothing severe in the forecast for the South Island’s east coast but conditions will become much colder as winds from the south or south east develop.”.

Canterbury – still mopping up from last months rain storm appears, at this stage, to be in the clear from any sustained torrential rain.  “In fact Canterbury could be a nice place to be for the next few days as the Southern Alps shelter the region from the worse of the weather”.