A Numerical Forecasting System for the Prediction of Slippery Roads

Abstract

A numerical forecasting system is presented for automatic prediction of slippery road conditions at road station sites in Denmark. The system is based on a road conditions model forced by input from an operational atmospheric limited area model. Synoptic information on cloud cover and observations of temperature and humidity from the road station sites are taken into account in a sophisticated initialization procedure involving flux corrections for individual locations. The system is run operationally at the Danish Meteorological Institute with promising results. Currently, new forecasts 5 h ahead are produced every hour for 200 road station sites. The potential of the model system is illustrated by model forecasts from two selected periods and operational results. Problems related to the accurate forecasting of road conditions are discussed.