Weather: 'Prepare for the blast' - MetService issues severe warning

Wellington is in for it as heavy rain moves towards the capital.

"Get ready Wellingtonians, here comes the southerly change," MetService said early Monday on Twitter.

"The Radar shows it just south of the Capital at 07:20am. Forecasting 55 gusting 85km/h on the change real soon." 

The front is currently moving north across the upper South Island and lower North Island, bringing heavy rain and strong winds.

MetService has issued a severe weather watch, warning rainfall could meet the warning criteria.

"Capital commuters should be prepared for this blast very soon," it says.

"A brief burst of heavy rain is expected until early afternoon today.

"During this time, rainfall may approach short duration warning criteria.

"Peak intensities of 20-30mm/hr are possible for an hour or two."

Meanwhile it will be mostly fine in Auckland, with a few showers producing a fantastic rainbow.

"Quite a large [rainbow] spans #Auckland's northern & western suburbs this morning," NIWA says on Twitter.

"A few odd showers in the air but a decent day ahead."