More rain, thunderstorms, big seas and possible high winds are behind the weather warning issued by Metservice this morning.

'We are looking at from about midday tomorrow until midday Friday, over those 48 hours 200-250mm to accumulate,” says MetService meteorologist Claire Flynn.

In the Western Bay of Plenty, rainfall rates up to 30-40mm per hour with thunderstorms are expected.

'The thunderstorms are more likely in Western Bay of Plenty. There's a moderate risk in the Eastern Bay. The higher hourly rainfall rates are more likely in the west but there are still going to be those accumulations. The rain is just going to keep going for a long time. Over the whole area.”

On Friday the former tropical cyclone Cook makes its presence felt. How long the rain will last, and whether the heavy rain warning will be extended will depend on cyclone's track.

'The warning goes out for 48 hours at the moment, but there is potential that it could be extended.

'The other thing we are concerned about with Bay of Plenty is that there are large swells coming in along the coast.”

On Thursday they are warning of swells rising to 5-6 metres.

'The winds are tricky because of that tropical cyclone,” adds Claire. 'The position of that will have a huge effect on how strong the winds get. So we don't have any watches or warnings for the wind with that, yet.

'We need more information before we can put that put. If the winds do get stronger they will add to those waves.”

Compared to Monday's predictions where the cyclone Cook remnant was passing East Cape well out to sea, today's prediction has it passing much closer to East Cape.

'We are likely to see the effects later in the week. We still need more information.

"Some current computer models suggest that Cyclone Cook could pass close to or over the northeast of the North Island on Thursday night or Friday. However, many other models are suggesting that it will remain further to the east."

As the final track of the cyclone will have a large influence on our weather, MetService is working closely with Civil Defence and local authorities to ensure that they have the most accurate and up to date information regarding both the heavy rain moving onto New Zealand from Tuesday, and also for Cyclone Cook.

TC Cook is expected to cross south of latitude 25S overnight Tuesday into Wednesday when forecasting responsibility is passed from Fiji Meteorological Service to the Wellington Tropical Cyclone Warning Centre area of responsibility.