KEY POINTS:
If the present pattern of weather continues, the chances of rain on Christmas Day are high, says MetService ambassador Bob McDavitt.
He said a rhythm of highs and troughs coming through from the Tasman was working in about a weekly cycle.
This was why the sun was shining predominantly during the week followed by at least one rainy day over the weekend.
"Probably around the 18th or 20th we'll have another high, and then from about the 22nd to 25th there will be another trough. Between the highs we will have these windy fronts."
The Herald tried to find a clairvoyant to back Mr McDavitt's experience and scientific know-how, but none would commit to predicting rain or shine for Christmas Day.
