NZ and Australia share weather risks over the next week as spring blasts kick in, says WeatherWatch.co.nz

A severe weather watch for heavy rain issued for the Bay of Plenty and Coromandel on Thursday, has now been upgraded to a warning.

"Low pressure dominates the North Island this weekend, after exiting Australia," says a statement from WeatherWatch.

"Rain and wind are both likely in the north while the South Island sees showers clearing in many regions with high pressure.

"By mid-next week a polar blast is possible… following the wintry change for Southland and Otago moving setting in right now."

Watch the full WeatherWatch.co.nz forecast above.