As a ridge of high pressure drifts eastwards, a deep trough will bring a period of rain and gales to many places this week, followed by a brief cold outbreak with snow to unseasonably low levels.
Northwesterlies spread up southern and central New Zealand ahead of an approaching front today. This flow brings cloudy periods to western places, with rain developing about the fiords this evening. Folk in the east can expect their run of fine weather to continue, with daytime temperatures reaching the mid-twenties in some places.
"On Tuesday there will be a period of heavy rain on the West Coast, and in the east, following a period of blustery northwesterlies, there will also likely be some decent rain which will be useful after a dry October," said Meteorologist Peter Little. Rain spreads over much of the North Island Tuesday night but the heaviest rain is expected there on Wednesday as the low progresses northwards.
A strong, cold southerly flow spreads over New Zealand following this weather system, with snow forecast as low as 300 metres over the south and east of the South Island on Tuesday. "There is the potential for significant accumulations of snow, especially about the inland Canterbury Plains, but the snow is not expected to affect those living in coastal cities or towns," added Little. A Watch for heavy snow is in force for Canterbury, Otago and Southland, in addition to the heavy rain and severe northwest gales possible in these areas. Road Snowfall Warnings have also been issued for some of the South Island passes, as well as a Heavy Rain Warning for Fiordland and Westland.
A new ridge of high pressure brings more settled weather over the South Island during Wednesday and Thursday, with frosty starts for most places. Meanwhile the low lingers east of the North Island directing rain into eastern areas along with large waves. The cold southerly will likely bring snow to the Desert Road and possibly some other high country roads for a time. Skies should be mostly clear over the South Island and in the north and west of the North Island by Thursday evening for those wanting to celebrate Guy Fawkes.
The ridge drifts over central New Zealand on Friday, clearing the rain from all but Gisborne, and once again northwesterlies build further south as another front approaches from the Tasman Sea ahead of the weekend.
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