25th September 2020 18:00NZST
We're currently watching a Spring storm which is expected to intensify in the Tasman sea, and move rapidly south east over the next day or so. The video below shows the ECWMF forecast from 3am Friday 25th September, though to around 3am Wednesday 30th September.
On the current model the low pressure starts over south Australia and Tasmania, but intensifies significantly as it moves south east. By Sunday midnight it sits SW of Stewart Island with a central pressure of 975mb. Associated with the low there are widespread showers across the country, with significant rainfall on the West Coast of the South Island, from a NW windflow.
During Sunday, the front moves up the country, dragging behind it cold polar air from the SE. Expect this to reach the middle of the country by around 5pm Sunday.
Overnight Sunday and into Monday the low pressure continues to deepen to the SE of the country, this time dragging snow to low levels across much of the South Island. Snow will continue to fall to low levels in Otago and Southland into Tuesday, while strong cold southerlies affect the rest of the country. By midday Monday, the Low pressure has a core pressure of 934mb, and lies about 1200km SE of New Zealand.
There are many warnings out for this system, and as always with a significant weather event like this, keep an eye on those forecasts and warnings on the MetService website
We'll be keeping an eye on this event over the next few days and provide updates to this blog as things progress. Feel free to provide your feedback in the comments section below, and let us know how things are going at your place!
Newshub - NZ weather: 'Significant wintry blast' to hit Monday after possible offshore 'weather bomb' sends severe, cold gales our way
NZ Herald - Severe weather: Widespread warnings as weekend weather bomb due to hit