"If the low is more west then Hawke's Bay could escape the worst of it but if it's more east then there will significant gale force winds."
Ms Murray said the winds would be the strongest in exposed places and about the coast.
This means there will be large swells which could cause coastal inundation and erosion if high tide coincides with the period of strong winds.
Meanwhile the rain will also be persistent and heavy for a period of time as the low moves down and the cyclone gets closer.
"There will be periods of rain but as the band around the low moves towards Hawke's Bay the rain will intensify by about Thursday afternoon."
There was a chance the severe weather watch for heavy rain could be upgraded to a warning depending on where the cyclone tracked today.
Unison Networks was asking residents to be prepared for the strong winds and rain as power cuts could happen.
Unison relationship manager Danny Gough said that even though Cyclone Cook was supposed to be fast moving, it was forecast to be very destructive.
"Its impact could also be greater due to the ground already being sodden from recent extreme rainfall, increasing the potential for flooding, trees falling and damage to powerlines."
Unison will have extra crews on standby in preparation, but is also urging customers to ensure they are prepared for potentially long periods without power.
"As part of your household emergency kit, make sure you have a battery operated radio and torch, a full gas bottle for cooking on your BBQ, and if you rely on electricity for heating, we also recommend a portable gas heater," Mr Gough said.
Parts of the country were already feeling the brunt of Cyclone Cook with a state of emergency being declared in the Thames-Coromandel District and Bay of Plenty.
Waikato Civil Defence had also warned residents to stock up on enough food and water for seven days.
According to MetService the forecast for the majority of the Easter weekend was looking much brighter.
Ms Murray said as the cyclone moves south the rain should clear and it should be a mainly fine day tomorrow.
"The winds may linger around the coast on Friday but Saturday and Sunday is looking like a nice couple of days which is great for Easter."
The temperatures for Easter weekend are expected to reach the mid-20s, making for a nice reprieve after the predicted lashing from Cyclone Cook.