A large high sits in the Tasman Sea today directing a cold southwestely airflow over New Zealand, a front within this flow moves over the North Island during this morning. Skies are potentially unstable behind this front in the afternoon. A ridge brings a settled period of weather to most of New Zealand on Friday however not for long, the second half of the day sees a northwesterly airflow strengthen over the South Island. A warm then cold front move onto the lower South Island later in the day.
Showers or rain will affect most parts of the North Island today, there is the risk of a thunderstorm and some hail in the afternoon about the Waikato and Bay Of Plenty then easing in the evening. Some snow to 700m about the Central Plateau and along the ranges of the east coast, early snow possible to 600m about Marlborough and Wellington. The South Island has a mixed bag of showers and sunny spells, morning rain about Nelson and Marlborough clears away then showers with a chance of hail and thunder is possible for Nelson in the afternoon before easing evening. Some hail possible in the afternoon for Canterbury also, perhaps the low risk of some thunder too.
A calmer picture for the North Island on Friday, southwesterly winds may still be a little breezy in areas. A few morning showers clear the east coast then sunny spells increase. As a northwesterly airflow builds over the South Island cloud banks up in the west with rain moving into South Westland from afternoon then pushing northwards overnight, drier in the east with some developing high cloud. Some scattered rain for Southland and Otago late afternoon or evening.
By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz