MetService has issued a severe weather warning for the central North Island.

"A front is expected to lie slow-moving over central New Zealand through to early Monday morning, bringing periods of rain with some heavy falls," says a MetService spokesperson.

"A Heavy Rain Watch for Mount Taranaki has been upgraded to an Orange Warning, and a Heavy Rain Watch is now in force for Tongariro National Park."

The heavy rain watch for Tongariro National Park is valid from 9am Sunday May 15 to 4am Monday May 16. Periods of heavy rain are expected and rainfall amounts may approach warning criteria.

People are advised to stay up to date with the latest forecasts in case any changes are made, or more areas added.