... I wonder if they're trying to cover the 'along-flow' organisation of these storms: those currently (1520Z) Sussex, Surrey, Wilts etc., seem to have some intense echoes buried in them and perhaps those will cause problems as the individual cells propagate along the flow and trigger daughter cells which could be equally intense - especially as they interact with the major M-way traffic etc.
Fine here now - we /may/ have escaped .... again :-)
Martin.