"With that persistent heavy rain there's the risk of flooding and slips. Heavy rain may cause streams and rivers to rise rapidly."
Rossiter said the highest rain reading from the past 24 hours had come from Waipawa with 23.8mm.
The rain was reasonably widespread with recordings of 20mm in Takapau and Mahia, and 17mm in Hastings.
"This should continue to rise. It's also quite a bit cooler compared to the average of 22C for this time of year, with Hastings reaching a maximum temperature of 19C on Thursday."
She said the wet weather was expected to carry the region through to the weekend.
Thursday's rainfall was the "perfect" amount for farmers still weary from last year's drought, Federated Farmers Hawke's Bay president Jim Galloway said.
"It seems to have been reasonably general. It's been not too heavy and it's soaked in."
He said the region had "dodged the heavy stuff" and the rain would help with grass growth.
"It was green and this follow-up will help grow it. The days are getting shorter and what we're losing out of the ground is getting less."
He said it would be important for farmers to watch out for facial eczema in their stock.
Rain is often bad news for vineyards bringing in their harvest, but Elephant Hill vineyard manager Brent Stone said this bit of rain wasn't going to worry him.
"If this rain carried on and we had it for days and it was warmer, it would be a bit more of a problem."
He said it had been a "funny season" but a good one.
"It is very advanced for everybody. They seem to get earlier every year."
The team was currently bringing in the reds and expected to be finished with picking in about two weeks.
"It could be a record for us."
The wet weather prompted a few events to be called off.
Napier City Rovers Football Club's under-15s and under-17s also called off their training sessions on Thursday night.
A Hawke's Bay Regional Council Walk and Talk on Coastal Birds which was to take place at Ahuriri Estuary was also cancelled.
Rough sea conditions predicted for this weekend have also seen the Napier Port Family Fishing Classic competition postponed - it will be held on March 27 and 28 instead.