(forecast, forecast or forecasted, forecasted) to say what you think will happen in the future based on information that you have now forecast something Experts are forecasting a recovery in the economy. Snow is forecast for tomorrow. It is difficult to forecast the demand for the new train service. forecast something to do something Temperatures were forecast to reach 40°C. forecast that… The report forecasts that prices will rise by 3% next month. forecast how, what, etc… It is difficult to forecast how the markets will react.