The MetService is predicting a chance of heavy rain and thunder this afternoon after issuing a severe weather warning for the Bay of Plenty.

'A large complex trough, with several embedded fronts and low centres, is slowly moving eastwards across New Zealand today and Wednesday,” says the weather organisation.

The MetService is predicting a chance of heavy rain and thunder this afternoon. Image: MetSerice/Twitter.

'The trough is expected to bring rain to much of the country. An embedded cold front moves east over northern New Zealand this afternoon and evening, bringing a burst of heavy rain, with squally thunderstorms about northern New Zealand.”

A few bands of heavy showers with squally thunderstorms in the very unstable airmass are expected tomorrow for central and northern New Zealand.

The largest amount of rain is expected about the ranges of the North Island.

'From late today until tomorrow evening, 130 to 180mm of rain is likely to accumulate about Mt Taranaki, 120 to 150mm about the ranges of eastern Bay of Plenty and about 150mm about the Tararua Range.

'People, especially trampers, are advised that this amount of rain could cause rivers and streams to rise rapidly, with surface flooding and slips possible.”

Thunderstorms expected for rush hour today (late afternoon early evening). https://t.co/ePtVj8cXwp ^EB pic.twitter.com/cOzqKTSvDm

— MetService (@MetService) May 23, 2016