Forecasting Weather â¢ Although models are useful tools in the forecasting process, subtle factors not included in the models can have a large impact on the weather. â¢ These factors include such things as urbanization. Urbanization is the fact that cities are warmer due to buildings and other man-made materials that absorb and hold heat that vegetation does not. â Urbanization can cause heat waves that the computer models cannot forecast â Urbanization can cause a cold rain in the city while surrounding suburbs receive several inches of snow. â¢ Forecasters use their knowledge of the local area weather patterns to modify the predictions they receive from the computer models.