Weekend Forecast 13th to 14th October

[Te Puke Weather]

Issued by The MetService

Saturday
Unsettled with rain or showers just about everywhere, but only scattered falls in Gisborne and Hawkes Bay and a few showers in the far south. Some heavy falls, especially in central areas and also the east of the South Island. Snow to fairly low levels in the South Island.

Sunday
Rain and showers easing, and clearing over much of the South Island. However, still some showers isn Otago and Southland,and showers spreading north along the South Island west coast.

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[OhauitiWeather]

WeatherWatch.co.nz forecasters are continuing to predict a severe weather system this weekend, with the government forecaster now also predicting rough weather and potential weather warnings.

On Monday WeatherWatch.co.nz first predicted the potential "weather bomb".  A weather bomb is when the air pressure falls 24hPa in 24 hours - this is still the likely prediction.

On Tuesday afternoon MetService issued a "moderate risk" for heavy rain across the West coast and Nelson, with a lower risk for western parts of the North Island south of Waikato.  These risks usually increase as the event moves closer.

WeatherWatch.co.nz head weather analyst Philip Duncan says the incoming low will be short and sharp.  "On Thursday the low will hardly exist - by Friday night it will be an offshore storm in the Tasman and by Saturday it will be starting to weaken already as it crosses New Zealand".  Mr Duncan says conditions may rapidly ease on Sunday.

"Saturday looks quite rough in a number of regions with the heaviest rain expected around north west areas of the South Island and the strongest winds to be in central and eastern regions".

The low is predicted to rapidly deepen in the central Tasman Sea on Friday, peaking at night before weakening slowly over Saturday and unravelling quickly on Sunday.

"These explosive lows can be short lived - as we saw with the weather bomb that hit South Taranaki and Wanganui back in March.  It was only 6 to 12 hours of very rough weather for those closest to the centre".

Mr Duncan expects most international flights to operate as usual this weekend but suggests there could be some delays - and those travelling on smaller regional aircraft could expect delays or cancellations on Saturday.

Domestic air travellers are advised to monitor forecasts and check their airline's website before flying.

WeatherWatch.co.nz says a more concrete prediction will be issued on Wednesday afternoon.

"Yes this is a nasty low but it's still only a moderately sized system - not everyone will be impacted by severe weather but this is still one that New Zealanders should closely monitor".

- WeatherWatch.co.nz
http://www.weatherwatch.co.nz/content/severe-weather-expected-weekend

[OhauitiWeather]

A potential weather bomb (when the air pressure falls more than 24hPa in 24 hours) is still expected to rapidly form in the Tasman Sea on Friday. While we expect the storm to peak out at sea, it will still be a rough Saturday for some areas - especially central New Zealand. By Sunday, however, it will be clearing already. Short and sharp.

Link to video:



-Weatherwatch.co.nz
http://www.weatherwatch.co.nz/content/weather-video-storm-race-over-nz-weekend

[OhauitiWeather]

This Saturday a large and deep low will move towards the South Island. There is likely to be some wild weather in many places with heavy rain on the West Coast of the South Island, gales being a main feature for the North Island and parts of the South Island. Snow will also feature high on the list for inland parts of the South Island above 400 meters.

The reason for the heavy snow potential given by WeatherWatch.co.nz forecasters is we’ll have a northerly airflow coming in from the northern side of the low bringing in lots of moisture then on the southern side of the low a cold southeasterly airflow undercuts the northerly airflow riding above. This type of snowfall is called warm advective snowfall and can lead to large amounts of snow falling.

A similar situation happened on the 6th June 2012 earlier this year however the air at the surface was much colder then hence snow fell to sea level. This system about to bear down on us will be quicker moving but fairly intense as it moves through.

For Saturday, heavy snow at this stage is likely to fall to 400m from Inland Otago up into South and Mid Canterbury, 500m and above for North Canterbury then down to 600m in Marlborough. Conditions are forecast to ease in all areas later at night.

Farmers and people travelling in the high country of the South Island this weekend are advised to take note and keep up to date with how this system will develop.


WeatherWatch.co.nz
http://www.weatherwatch.co.nz/content/heavy-snow-possible-inland-south-island-saturday

[OhauitiWeather]

In today's weather video we run through the nasty low that is today rapidly deepening. We track it across Saturday in high detail. It will be a short and sharp storm that will cross central New Zealand bringing heavy rain, strong to gale force winds and even some heavy snow for higher altitude parts of Canterbury. Some regions will also have sun - all in all it's a typical spring system!

Link to Video:



WeatherWatch.co.nz
http://www.weatherwatch.co.nz/...rm-cross-nz-saturday

[OhauitiWeather]

This system is still on track to develop heavy snow to the high country in the South Island tomorrow. It must be reinforced that mainly this snow event will be at higher altitudes, people living in the main centres will not notice any snow. Heavy rain is likely for Christchurch tomorrow however and places like Little River and lower lying areas about the Heathcote River may get some flooding.


 
The snow risk area is for inland areas and extends from North Otago through to Southern Marlborough tomorrow. Snow falls do look a bit more forgiving in latest data not because the amounts of precipitation have changed but the freezing levels are not lowering as fast now. Snow is now likely to start falling a bit higher at first in the morning then gradually lowering during the day. Falls in North Otago and Canterbury are expected to 800m at first in the morning lowering during the day to 400m by evening then clearing at night.
 
Southern parts of Marlborough are still inline for snow, to 1000m after midday then lowering to 500m in the evening and clearing later at night.
 
High up on the Ski fields like Mount Hutt there is likely to be large amounts of snow tomorrow, the season there has been extended to the 14th October but this could even make it a little bit longer.
 
Places like Porters and Arthurs Pass are likely to be closed from tomorrow afternoon or evening due to snow fall so make travel plans accordingly.
 

WeatherWatch.co.nz
http://www.weatherwatch.co.nz/...w-track-high-country

[OhauitiWeather]

We can say goodbye to the low on Sunday, but not its influence.
 
As the low treks off to the east, it will leave some rather breezy conditions in its wake. Winds won’t be as strong as what we saw today. But breezy to brisk sou’westerlies can be expected about the eastern South Island and breezy westerlies will be found about most of the North Island during the first half of tomorrow.
 
In addition, a weak trough of low pressure will be stretched out across central New Zealand tomorrow morning. That will set the stage for some lingering showers about the upper South Island and lower North Island in the morning. That means people in Wellington and New Plymouth can expect to see a wet start to Sunday. The showers could extend as far north as Gisborne and Hamilton.
 
As we approach the noon hour tomorrow, that trough and the precipitation associated with it will slide north. That means the central North Island could see some showers, including Hamilton and Tauranga.
 
The weather will also be unsettled enough to keep chances for showers going throughout the day about the upper tip of the North Island, including Auckland.
 
A few shower chances can’t be ruled for the early part of tomorrow for Christchurch either. But drier weather and clearing skies will be the trend as Sunday wears on.
 

By WeatherWatch.co.nz Weather Analyst Howard Joseph
http://www.weatherwatch.co.nz/...it-showers-ni-sunday