People in and around Gisborne, the East Cape and Hawke's Bay should keep an especially close eye on weather forecasts as Pam approached, MetService said.
Gisborne Civil Defence spokesman Richard Steele said Gisborne residents should be prepared for strong winds, large sea surges, coastal erosion, some rain and power loss.
Road closures were also expected, particularly at Tatapouri where State Highway 35 ran close to the sea, he said.
"We advise people to tie down anything that might fly away, get enough food and water for three days and secure boat moorings," he said.
"In addition, check spouting, but take care if using a ladder, and have a tidy up around the section putting away or securing loose items. There is likely to be roading damage overnight Sunday so check road conditions before travelling especially on the coast."
Hawke's Bay Civil Defence spokesman Ian McDonald said it was preparing for the strong possibility of heavy swells and strong winds on the coast.
"People need to make sure their family emergency plans are up to date, with their properties prepared for strong winds, and a getaway kit all ready - just in case," he said.
Hawke's Bay Civil Defence would keep people up to date through its website and Facebook Page, he said.
Auckland Civil Defence controller Clive Manley said Aucklanders should exercise caution as the region could be hit by severe weather on Sunday evening.
"Current weather forecasts suggest areas north of Whangaparaoa and on Great Barrier have a reasonable chance of river and stream flooding, strong winds, large swells, waves and coastal erosion," he said.
"Surface flooding and slips may make driving difficult from Sunday evening until Tuesday. There may also be local power cuts."
It was a good time to check emergency survival kits and update household emergency plans, he said.
"Make sure you have a battery-powered torch, radio, food, water and other essentials in your emergency survival kit.
"If you live in a low-lying area prone to flooding, you should have a getaway kit ready in case you need to move to higher ground."
Other messages from Gisborne Civil Defence:
• Listen to local radio.
• Make sure you have sufficient water and food to last three days.
• Treat all power lines as live at all times.
• Clear gutters and drains on your property.
• Have matches ready to light gas appliances.
Gisborne Civil Defence will broadcast on the following stations during an emergency:
• 945 kHz AM - Talkback ZB
• 585 kHz AM - Radio Ngati Porou
• 90.9 FM - ZGFM
• 98.1 FM - Radio Ngati Porou
• 98.9 FM - More FM (Urban Gisborne)
• 90.1 FM - More FM (Rural areas)
• 94.9 FM - Radio Live
• 91.7 FM - Turanga FM
• 88.5 FM - Uawa
- Track Cyclone Pam in real-time here -
