What is another word for "harbinger"?

Roget's Thesaurus (1911) lists these synonyms for "harbinger": antecedent, augury, auspice, avant-courier, bellwether, bird, candle, dawn, exordium, foreboding, forerunner, foreword, frontispiece, gathering, groundwork, heading, herald, ill, ill-boding, inaugural, indication, introduction, introductory, leader, omen, outrider, overture, pioneer, portent, preamble, precedent, precursor, precursory, predecessor, preface, prefatory, prefigurement, prefix, preliminary, prelude.