A rather wet pattern is setting up for Monday. Rain is likely for much of the western South Island and a large part of the North Island.
 
Expect widespread rain along the western sections of the South Island tomorrow morning. Some precipitation is also possible about coastal Southland. Canterbury and Otago will probably stay dry until the late afternoon or evening hours.
 
On the North Island, showers will have spread across much of the island by sunrise. Wairarapa, Hawkes Bay and Gisborne will likely have to wait until mid-morning to see any rain.
 
Heavy rain is a threat tomorrow, but the best chance for it would be during thunderstorms. Right now, the best chance for thunderstorms will be about West Coast, Nelson and the Kapiti Coast during the afternoon and evening. Government forecaster MetService has identified these areas as having a “high risk” for thunderstorms.
 
Thunderstorms area also possible for eastern Otago and Canterbury, including Christchurch. These areas are running a moderate risk. Also running a moderate risk are Taranaki and Waitomo. All of these regions would most likely see thunderstorms during the afternoon and evening.
 

By WeatherWatch.co.nz Analyst Howard Joseph
http://www.weatherwatch.co.nz/content/october-starts-wet

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.
 

- WeatherWatch.co.nz
http://www.weatherwatch.co.nz/...t-windy-blast-coming

Tomorrow will be the day of the southwesterly. The North Island is likely to receive some rain or showers in the morning then easing in the afternoon and clearing with sunny areas developing in most places, winds will be a bit brisk but nothing harmful. The east coast will start the day with west to northwest winds but southwesterlies will creep north in the afternoon bringing a few showers. A few showers may linger about the Hawkes Bay and Gisborne ranges till evening then clearing at night.



For the South Island the front will have already started to pass over in the morning so it will be a day of southwesterlies easing and morning cloud breaking, with sunny periods increasing. Wet weather is looking rather unlikely although morning showers about Buller could be likely and a few lingering showers about Southland and Otago are possible but they will clear early on.
 
Later in the evening a northwesterly airflow develops over the South Island so high cloud will start to increase from evening tomorrow and rain will develop on the West Coast overnight. Friday is likely to see quite strong northwesterly winds for many places.

Homepage image / 4th October 1pm rain map - weathermap.co.nz

 
By weather analyst Aaron Wilkinson, WeatherWatch.co.nz
http://www.weatherwatch.co.nz/...hwesterlies-thursday