Valid from Monday 10 September 2012 to Thursday 13 September 2012
A strong, cool southwest flow should become established over the country on Monday behind a front preceded by strong northwesterlies. The front should bring periods of heavy rain to western parts of both islands, especially about the ranges. There are currently Severe Weather Warnings and Watches in place for many areas of New Zealand for either heavy rain or severe gale winds.
There is low confidence that rainfall warnings will extend into Monday for the ranges from Waitomo through to Wellington, including across to the Central Plateau. For northwest Marlborough, Nelson and the South Island West Coast, there is low confidence that rainfall warnings will still be in place on Monday.
There is low confidence that a wind warning will be required on Monday from Waitomo through to Wellington, including the Central Plateau. For central Hawkes Bay, Wairarapa, Wellington, also Marlborough and the ranges of North and Mid Canterbury, there is moderate confidence that a wind warning will be in place on Monday and low confidence that they will extend into Tuesday.
For Southland, Otago, South Canterbury and the Canterbury Plains there is moderate confidence that wind warnings will be required on Monday and low confidence that they will extend into Tuesday.
Snow to low levels is likely late Monday and Tuesday for the far south of the South Island and snow accumulations may be significant enough below 500 metres to justify a warning. There is low confidence that a heavy snow warning will be in place for Fiordland late Monday and Tuesday and for Otago and Southland on Tuesday. As the cold air moves north, there is also a possibility that snow accumulation over the central North Island high country may be significant enough below 1000 metres to justify a warning. On Wednesday, there is low confidence for a heavy snow warning for the central plateau and the ranges of Wanganui.
On Wednesday, a large high should move over the North Island and northern South Island bringing a respite from the wind, rain and snow in many places.
On Thursday, a strengthening moist northwest flow becomes established over the South Island as the high moves away to the east. There is moderate confidence that rainfall warnings will be required for the South Island West Coast south of the Glaciers.


Metservice


Weatherzone

Philip Duncan and nzherald.co.nz team up to bring you the very latest on the snowy snap for Tuesday, the high moving in for Weds and Thursday and then the next rain and wind maker coming in for - you guessed it - the weekend!

Link to Video:



-WeatherWatch.co.nz
http://www.weatherwatch.co.nz/content/weather-video-antarctic-snap-coming-south-island

ISSUED BY MetService AT
9:46 am 11-Sep-2012

Snow for the Central North Island and the lower South Island, with heavy falls possible.
A strong southerly airflow is bringing snow to the lower South Island and is expected to spread north affecting the central North Island this afternoon. Snow is already falling to sea level in Fiordland, Southland and Otago and snow is expected to affect the lower North Island this afternoon and evening. In areas of Fiordland, Southland and Otago, snow accumulations of 20 to 30cm are likely during today above 300 metres. For the central North Island ranges of Taihape, the Kaweka Range of Hawkes Bay and northern Manawatu, accumulations of 20 to 25cm are possible above 800 metres from this afternoon through to early Wednesday morning, with the heaviest period of snow expected late this afternoon and evening.
These amounts of snow have the potential to be disruptive by affecting roads and passes, and the weight of accumulated snow could damage trees, powerlines and weak structures.
Also, the combination of the strong winds with the snow or very cold showers will lead to significant wind chill. These conditions could cause distress for livestock without shelter.

HEAVY SNOW WARNING
AREA/S AFFECTED
Fiordland, Southland and Otago
FORECAST
A very cold southerly flow is bringing snow showers down to sea level about Otago, Southland and southern Fiordland during today. In the 12 hours from 9am Tuesday, expect 20 to 30cm of snow to accumulate above 300 metres about the ranges west of Riverton, the Catlins, inland areas of Southland and the southern ranges of Central Otago. Also, 5 to 10cm may accumulate during this period down to 200 metres.
FREEZING LEVEL: 400 metres.
AREA/S AFFECTED
Central North Island ranges from Taihape and the Kaweka Range of Hawkes Bay to northern Manawatu
FORECAST
Showers are expected to turn to snow above 700 metres from late morning and lower to 400 metres this evening. In the 18 hours from 3pm Tuesday, expect about 20cm to accumulate above 800 metres and 5 to 15cm to accumulate down to 600 metres. The heaviest period of snow is expected to be late this afternoon and evening.
FREEZING LEVEL: 1200 metres lowering to 700 metres to this evening.

Sunny weather is slowly spreading across the country - but it will be short lived says Philip Duncan in today's nzherald.co.nz weather video.

While some areas still have cold, wintry, conditions today - the sun is moving in and the showers clearing.

Thursday and Friday look settled, sunnier, warmer and drier for just about every region in New Zealand - but on Friday that starts to change on the West Coast - with a large low moving in for Saturday for most places.

Link to Video:



-Weatherwatch.co.nz
http://www.weatherwatch.co.nz/content/weather-video-sun-return-briefly-ahead-weekend-rain

Friday is still looking as mentioned yesterday, fine and sunny weather over the North Island with north to northeasterly winds picking up later in the day with some cloud in the west. On the east coast expect sunny skies all day with light winds. Fine out east in the South Island with high cloud and increasing north to northwesterly winds bringing mild temperatures. A few brief showers get into Southland and perhaps Otago later in the day as winds ease. Expect rain on the West Coast.



On Saturday skies will be mostly cloudy over the North Island with brisk northerly winds, rain develops in the west during the morning then clears later in the day as winds change westerly. Fine out east with high cloud and breezy northwesterlies, showers later at night as winds change more southerly. Fine on the east coast of the South Island with high cloud, a southwest change moves through from afternoon in Otago through to Marlborough at night bringing a period of showers. Another period of showers moves up the West Coast also and there could be a few thundery falls in the mix.

On Sunday skies will have sunny areas and some cloud over the North Island with a few showers on the east coast with southerlies. In the afternoon and evening isolated showers may pop up south of Auckland and through many inland areas bringing a risk of thunder. Any morning showers clear in the South Island with sunny breaks then increasing as southwesterlies ease. Perhaps the low risk of an isolated afternoon shower about Marlborough and inland areas of North Canterbury about hills and ranges.


Homepage image / 14th September midday rain map - weathermap.co.nz

By weather analyst Aaron Wilkinson, WeatherWatch.co.nz
http://www.weatherwatch.co.nz/content/friday-and-weekend