Aircraft in LAM Lambourne hold reports large orange balloon

At 1700 GMT Saturday, January 25, 2014, an aircraft in the Lambourne stack reported passing a large orange balloon. A very intense storm with lightning and intense rain was occurring to the south and traffic was rarely put into a right hand orbit. The unknown aircraft was destined to EGLL Heathrow Runways 27. Aircraft were leaving the stack at FL 90.