Source : Webster's Revised Unabridged Dictionary (1913)

Prognosticator \Prog*nos"ti*ca`tor\, n.
   One who prognosticates; a foreknower or foreteller of a
   future course or event by present signs. --Isa. xlvii. 13.

Source : WordNet®

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