By Lucy Thornton The bank holiday is expected to end with a bang tomorrow with the arrival of “hefty” downpours and thunder. However things are looking up for Tuesday when Brits return to work. The arrival of British summer time was greeted by more rainfall on Sunday, with families warned to leave later to avoid the Easter deluge. The Met Office warning for rain on Sunday night prompted the RAC to advise the two million motorists heading home to leave it until later. The affected regions included Portsmouth, Southampton, Bristol, Bath and Cardiff where up to 20mm-30mm of rainfall were expected…