Ambrose was born in Grays, Essex, and studied at South East Essex Technical College and School of Art in Dagenham, followed by a year at the RA Schools under Peter Greenham. His wife was Moyra GILCHRIST, and the couple lived in Newlyn.
He was an artist of many talents, spanning the full range from teaching art to producing drawings, prints and paintings in oils and watercolour.
Locally he exhibited at the Orion Gallery, Penzance and then at NAG, in mixed and solo shows. He died of heart failure at Penzance Railway station as he was taking paintings to London.