This YouTube from the Met Office goes on to say...Paul Gundersen, Deputy Chief Forecaster, explains why most of the UK is experiencing a late September "heatwave" and how long it will last.
No, that is NOT the answer, this heatwave is the result of the activity from Sunspot 1302, as per forecast from WeathAction in AUGUST!! What the Met Office is missing out is the "cause" of how the High pressure system started, they are giving the viewer on this YouTube the "effect" as being the "cause".
High pressure systems do not happen by magic and it's worth showing you the current link to the WeatherAction page for more detail on this period.TwitPic Link WA No. 23