forecaster UK /ˈfɔːkɑːstə/US /ˈfɔɹkæstəɹ/ noun2 •A person who forecasts.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. — 1995 •A software program or algorithm that forecasts. formsforecasters