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Webster 1913 Edition

Noun.

One who forecast.

Johnson.

Noun.

One who foresees or contrives beforehand.

forecaster ‎(plural forecasters)

A person who forecasts.
- 1995, Keith Kyker, Christopher Curchy, Video projects for elementary and middle schools (page 79)
  Students will be surprised to see the weather forecaster is not really standing in front of the maps. These are keyed in electronically; the forecaster stands in front of a green/blue screen.