A new MetService forecast shows another 70mm to 90mm of rain may be on its way for Northland, with people warned to be vigilant and stay off the region's roads overnight.
The new severe weather warning - issued at 4.11pm - shows rain is expected to continue in Northland until midday tomorrow, but at lesser intensities and with southeast gales easing this evening.
Graeme MacDonald, spokesman for the Northland Civil Defence Emergency Management (CDEM) Group, says with the large volumes of rain that have already fallen today, the further rain could still be an issue for many parts of the region.
Officials will be keeping a close eye on rain and tidal conditions as the high tide approaches both about 6pm today and again just before 7am tomorrow; particularly in the eastern coastal areas south of Kaikohe.
A number of roads remain blocked by floodwaters and fallen trees - including several parts of the region's State Highway network - and authorities are urging people to stay off the roads and not to attempt to negotiate floodwaters overnight.
Police are advising that one of those State Highway blockages - at Whakapara north of Whangarei - is currently able to be bypassed via a detour along Apotu Rd and Jordan Valley Rd near Hikurangi, however, the detour is not able to be used by trucks and heavy vehicles.
Officials from dairy giant Fonterra are also warning that night collections from Northland suppliers could be disrupted or not take place due to flood-related roading issues.
Top Energy advises power remains off at about 1200 homes in the South Hokianga area, however, it hopes to restore that early this evening provided no new network damage is discovered.
Meanwhile, Mr MacDonald says the Far North and Whangarei District Councils have plans in place to activate welfare centres overnight in their areas if this proves necessary. He says Civil Defence officials will be monitoring the situation overnight.