Australia's major centres face a variety of weather conditions leading up to Christmas Day, and for some lucky cities the rain looks set to clear in time for Santa.
South-east Australia is currently trapped in an unusually prolonged spell of cold southerly winds just over a week before Christmas.
The sub-polar airmass has sent temperatures 15 degrees below average and brought snow to the Alps on four consecutive days.
The question is will the unseasonable chill, which started back in early November, last another 10 days?
How can a forecast be produced 10 days out?
There's an obvious reason the Bureau of Meteorology produce a seven-day forecast and not a 10-day forecast.
Weather forecasting is a complex science with a near infinite number of variables to consider.
However, accurate day-to-day forecasting does exist beyond a week and can be stretched to even two weeks in some circumstances.
The modelling used to produce the daily seven-day forecast has output well beyond this, so the forecast method is similar but adjusted to compensate for the lower reliability.
Christmas weather pattern
The current cold spell will come to an end for south-east states around the middle of next week, but warm weather will only last a couple of days as a band of rain and storms sweeps across south-east Australia from Wednesday 21 to Friday 23.
Promisingly this system is arriving before Christmas which should allow enough time for most of the rain to clear in time for Santa.
While there are high hopes of a mostly dry Christmas for the south-east states, models are indicating a cold front will be passing over far south-east Australia about Christmas Day.
This could bring a shower to southern cities like Melbourne and Hobart.
For south-west WA the current regime of warm, dry easterly winds should continue, and that puts Perth in prime position to be the warmest capital on Christmas Day.
Across tropical Australia an increase in rain is likely next week for the Kimberley and Top End as a monsoon forms, although at least the cloud and maritime winds will keep temperatures down for Santa's arrival.
For Queensland, the Christmas period is likely to be warm and humid with the risk of showers and thunderstorms in most regions.
For our major centres here is a detailed breakdown of the most likely weather on December 25:
Adelaide
A cool southerly is likely which should keep temperatures a few degrees below average. There is only the slight risk of a light shower.
Ballarat
A relatively cool day is likely although one model, an outlier, currently has a much warmer airmass over Victoria. If that front arrives on Christmas Day then a shower is possible.
Bendigo
A mostly sunny day is favoured with temperatures near average for December although one model, an outlier, currently has a much warmer airmass over Victoria.
Brisbane
A relatively cloudy, warm and humid day is likely across south-east Queensland which could produce a shower or thunderstorm, although they are more likely over inland regions.
Cairns
The trade winds are likely to weaken in the days leading to Christmas which should ensure a warm and humid day. There is also the possibility of a shower or thunderstorms although they are more likely inland from the coast.
Canberra
A partly cloudy and warm day is likely, although there is the slight risk of a shower or storm later.
Darwin
With a monsoon forming in the lead up to Christmas Darwin is likely to be the wettest capital. The cloud and westerly winds should keep temperatures below average.
Gold Coast
A relatively cloudy, warm and humid day is likely across south-east Queensland which could produce a shower or thunderstorm, although they are more likely over inland regions.
Hobart
A fairly typical summer day is likely although if the front mentioned above arrives on Christmas Day then a shower is possible.
Newcastle
Rain from the days leading up to Christmas should clear by the 25th. A partly cloudy day is favoured with temperatures near average.
Maroochydore
A relatively cloudy, warm and humid day is likely across south-east Queensland which could produce a shower or thunderstorm, although they are more likely over inland regions.
Melbourne
A relatively cool day is likely although one model, an outlier, currently has a much warmer airmass over Victoria. If that front arrives on Christmas Day then a shower is possible.
Perth
A spell of dry easterly winds is likely to continue. This should ensure Christmas Day is mostly sunny and warm.
Sydney
Rain from the days leading up to Christmas should clear by the 25th. A partly cloudy day is favoured with temperatures near average although western suburbs away from a sea-breeze could nudge 30C. A slight risk of a late shower or storm for the west.
Toowoomba
A relatively cloudy, warm and humid day is likely across south-east Queensland which could produce a shower or thunderstorm.
Townsville
The trade winds are likely to weaken in the days leading to Christmas. This should should ensure a warm and humid day and the possibility of a shower or thunderstorms although they are more likely inland from the coast.
