1. a short demo …. VejVejr is an internetbased surveillance and forecasting system, developed by DMI and Vejdirektoratet. VejVejr provides any tools needed to secure proper decisionmaking with regards to preventing slippery roads. Contacts: Pernille Arnsfelt Hansen DMI – pah@dmi.dkpah@dmi.dk Søren Brodersen DMI – sb@dmi.dksb@dmi.dk

2. Slippery roads when: Road-temperature < 0 Rime - dewpoint is higher than road-temperature Ice – moisty or wet roads Precipitation We need to know: Road-temperature – actual and forecasted Humidity – dewpoint Precipitation Cloudcover Road condition – wet, moisty, salinity, freezingpoint etc.

3. Actual time or historic mode

4. Road T > + 2 Road T < + 2 but above 0 Road T < 0 Road T < 0 and dewpoint higher (riming)

5. Worst status next 5 hours

6. Choose your local area…

7. Forecasts for each roadweatherstation doubleclick!

8. Alarm status

9. Observations T 2m Road T dewpoint

10. Forecast Road T < 0 from 02.50 hours Dewpoint is higher – this means riming (hoar frost)

11. Road resistance – how wet is the road ? Dry Moist Wet Salty

12. Forecast of precipitation – time/type/intensity Forecast of cloudcover Forecast of wind – direction/speed To 24 hour forecast

13. 24 hour forecast Forecasted precipitation: Snow Snow and rain mixed Rain

14. Area-forecast

15. Comments from meteorologist

16. Online radar data – 10 min intervals Precipitationtype and intensity: Rain Rain and snow mixed Snow (or freezing rain) Animation

17. Online satellitedata from MSG2 – 15 min interval Cloudtype color-code: Dense clouds – Weak radiation, weak road-cooling. Scattered clouds – Periodic radiation, some road cooling. Cirrus – Thin clouds, some radiation, some road cooling. Animation Allows you to follow changes in cloudcover – to spot areas with either clear weather (and cooling/radiation) as well as clouds that provide little or no heat-insulation.

18. Help - explanation Online help to all screen-images

19. Online Web-cams

20. Regional text-forecast 7 days text-forecast

21. Observations from roadweatherstations - graphics Roadtemperature

22. Roadcondition

23. Precipitation

24. Salinity

25. Freezingpoint

26. Roadweather observations for your chosen area - text

27. Observations from specific roadweatherstation - text

28. Animation - your own choise of observed parameters This function allows you to follow any weather development, for instance roads cooling or precipitation spreading. All observations can be animated and color- coded as you like it…

29. Graphics – your own choise of visualisation

30. Wind forecast (for bridges mainly)

31. How does it work …?

32. INPUT: Observations, from roadweatherstation. Meteorological stations Satellite data (clouds) Atmosphere condition from HIRLAM weather model. …compute OUTPUT: Future road condition. Numeric ROAD CONDITION model

33. Model area and road weather station network Exclusive forecast available for each road-station.

34. Verification 2006-2007 : Mean ABSOLUTE error. (Situations with road temperature between -3 and +3) Distribution of the 3- hour forecast error. Error in degrees Celcius

35. Thank you for your attention. If you have questions or things you would like further explained, please contact us anytime. Pernille Arnsfelt Hansen, meteorologist, pah@dmi.dkpah@dmi.dk Søren Brodersen, senior meteorologist, sb@dmi.dksb@dmi.dk