Northlanders are being warned to brace for heavy rain, with the MetService predicting up to 130mm of rain could fall on the region in 21 hours from 6pm tonight.

The severe weather warning is for heavy rain for Northland from 6pm this evening until 3pm tomorrow.

MetService said a humid easterly flow over the northern half of the North Island is expected to spread further south during Thursday and Friday reaching the upper South Island on Saturday.

An active front embedded in this flow is forecast to move south across the North Island during this evening and Friday bringing rain to many places.

Advertisement

The heaviest rain is expected in Northland where up to 130mm of rain could accumulate, mainly about the eastern hills, from this evening till-mid afternoon Friday and a warning is in force.

It says there will be periods of rain, with heavy falls and possible thundery downpours. During this period, 100 to 130mm of rain is expected to accumulate about eastern hills and a lesser amount of 60 to 90mm elsewhere.

MetService said further heavy rain is possible about the eastern hills of Northland from Friday evening till midnight Friday.

For the latest weather information check out http://www.metservice.com.