"We're going to see some rain associated with that and probably quite strong northeasterlies. There could be some heavy falls on Monday and also on Tuesday and things will ease off a little going into Boxing Day."
Ms Murdoch said it was likely Metservice would issue a weather warning closer to Monday so she advised people in Rotorua to keep an eye on the forecast.
Ms Murdoch said she couldn't comment on the weather further ahead but Metservice's 10-day forecast for Rotorua predicted rain right up until New Year's Eve, with low- to mid-20C highs.
Weatherwatch.co.nz's outlook for Christmas Day was for showers, with some sun moving in briefly at times too and very humid north to northeast breezes.