Soothsayer :  (noun)

1: someone who makes predictions of the future (usually on the basis of special knowledge) [syn: forecaster, predictor, prognosticator]

Cassandra, Druid, astrologer, augur, calamity howler, crystal gazer, divinator, diviner, divineress, forecaster, foreknower, foreseer, foreshower, foreteller, fortuneteller, geomancer, haruspex, palmist, predictor, prefigurer, presager, prognosticator, prophesier, prophet, prophet of doom, prophetess, psychic, pythoness, religious prophets, seer, seeress, vates, weather prophet,