Glassey said the weather would affect most of the Bay of Plenty.
"It's looking pretty similar for Tauranga and the Western Bay of Plenty with heavier rain likely for the ranges of the Eastern Bay of Plenty."
"There is a risk of thunderstorms as well decent wind gusts," Glassey said.
A heavy rain watch was issued by MetService at 10.35am and said rain could reach warning levels in some parts of the Bay of Plenty between 11am and 7pm on Wednesday.
The weather looks set to improve on Thursday before a new front brings in more showers on Friday.
According to Metservice, the lowest temperatures are set to dip to was 7C overnight on Wednesday and Friday, with the temperature hovering around 9C on Thursday.
Bay of Plenty Federated Farmers provincial president Darryl Jensen said farmers could always do with some rain especially after the extremely dry summer.
He said most farmers had dried off their cows and had decreased stock numbers.
While most of the region had enough feed it was still "tight" in some areas such as the Kaimāi Ranges, he said.
At this stage, the wet weather would only become a problem if the temperature dropped as this would slow down grass growth, he said.
However, having a harsh winter often led to a "brilliant" spring which would spur on growth.