AN amateur weather forecaster has predicted a white Christmas this year – based on the season's weather patterns.
Martin Harris, of Spondon, said his conclusion was based on jet-stream patterns.
These are narrow air currents in the Earth's atmosphere which are sensitive to condition changes and can be therefore be used to monitor weather patterns.
The northern-polar jet stream is considered to be the most important one for weather forecasting, as it is much stronger and at a much lower altitude than the subtropical jet streams.
This stream covers countries in the northern hemisphere, while the southern polar jet stream mostly circles Antarctica and occasionally the southern tip of South America.
Mr Harris said: "This is the best chance we have had of a white Christmas in a long time.
"Officially, only one snow flake needs to fall for it to be classed as a white Christmas, according to the Met Office.
"The jet-stream pattern I'm looking at is a ribbon of air eight miles above the surface which comes from the US."
Mr Harris said his prediction was also based on seasonal temperature averages.
He said: "Normally, you'll have it where one week is in something like double figures but then it can change.
"But November was spot on in the single figures and this indicates December is likely to be freezing. It is early to be too precise, though."
Martin has a page on social networking website Facebook which specialises in long-range forecasts. It can be found by searching WeatherupdatedDerby.
Bookmakers firm William Hill is offering 3/1 odds against a white Christmas in Aberdeen but rather longer odds – 6/1 – against London getting snow on December 25.
Birmingham, the closest city to Derby of those which have been allocated odds, has been given a 5/1 chance of getting snow this Christmas.
