Access is closed off on this road in Piha. Photo: RNZ / Marika Khabazi
Hawke's Bay is in for periods of heavy rain for 48 hours from midday on Thursday through to Saturday, the MetService says.
MetService has urged people to watch its forecasts, with heavy falls possible about hard-hit Gisborne also.
It is also forecasting more rain for Auckland, starting this afternoon.
Auckland Emergency Management duty controller Rachel Kelleher says the rain is not expected to cause flooding, but could cause existing slips to fall further.
She says emergency services are ready to respond if the weather situation escalates. People need to stay away from cordoned areas and not interfere with traffic management signs.
In an update yesterday MetService said there was "high uncertainty" with its forecast for Hawke's Bay with 50mm forecast for Wairoa, "others are more pessimstic".
More than 9000 households are still without power more than a week on from devastating Cyclone Gabrielle with some in rural areas facing weeks to have it restored.
Hawke's Bay electricity company Unison says crews got most of Napier city back online yesterday.
It says it got started on work in Taradale yesterday afternoon, and aims to have power back on in Te Awa by tomorrow.
But isolated rural areas could take weeks to hook up again, though Unison says it has managed to restore power to 70,000 customers since Gabrielle struck last Monday.
In Tairāwhiti, more than 300 households are still without electricity. People in all cyclone-hit areas are being asked to conserve power where possible.
Eleven people have been confirmed killed in the cyclone.