'Indian summer' on its way by middle of next week
Following another disappointing summer, and an unsettled September, at long last a spell of warm weather will be on its way by the middle of next week.
A plume of warm air from the continent looks set to move northwards across the UK reaching many areas by Wednesday; with a good degree of agreement between all the main forecasting centres.
The meteorological chart shown below for friday of next week is called a 'thickness chart', and allows us to calculate temperatures. The lime green line, labelled 564dm, indicates the thickness of the atmosphere between 1000millibars and 500millibars. To have this line, and warmth, so far north is very unusual for this time of the year.
If this chart is correct, then temperatures in London, for example, could reach 27C (81F) by the end of next week.
High Autumn temperatures in late September/early October last occurred in 2006, and before that in 1995. Locally 1st October 1985 was exceptional, with 27.5C recorded at Leeds weather centre.
Such autumnal warmth is often described as an Indian summer, but technically speaking an Indian summer is a term to describe a warm spell of weather much later in the season, usually late October into early November.
The maximum temperature chart shown below, based on the American model for Wednesday gives an idea of the extent of the warm weather by that time, with many areas enjoying temperatures in the low 70's Fahrenheit.
This compares very favourably to the average temperature for the end of September in Leeds, for example, which is around 16C (61F).
Although in some areas mist and fog could be slow to clear during the mornings, this 'Indian summer' could last in some areas into the following weekend, if computer predictions are correct.