FSL’s Ensemble of Mesoscale Models – Lessons Learned from the 2003 MDSS Demonstration

1. FSL’s Ensemble of Mesoscale Models – Lessons Learned from the 2003 MDSS Demonstration Paul Schultz October 15, 2003

2. FSL model data CRREL Road temp/chemical module MIT/LL rules of treatment practice GUI in the field NCAR Road Weather Forecast System Maintenance Decision Support System • Sponsored by FHWA • Cooperative 5-yr project with NCAR/RAP, CRREL, MIT/LL • Help snowplow garage supervisors decide when/where to send trucks, chemical treatments • FSL: produce supplemental model runs and transmit them to NCAR

3. MDSS field trip, March 2-5 Downward-pointed radiometer mounted on rear-view mirror of Jim Van Sickle’s truck RWIS tower, I-35 south of Ames Bob Stradley and Ron Simmons

4. MDSS main screen display

5. MDSS alert category classification

6. Forecast point status display Place cursor over a forecast point

7. Time series display Temp and Dewpoint Wind Speed Wind Direction Visibility

8. Treatment Selection Screen The default treatment screen shows forecast traces of mobility index (1.0 being the best). We have not yet selected a treatment. Hence, the “current plan” depicts decreasing mobility The MDSS automatically generates an optimized recommendation of treatments

9. The ensemble for Demo 2003 • Mesoscale models centered on Iowa • Six ensemble members • models: MM5, RAMS, WRF • LBC sources (from NCEP): AVN, Eta • Initialization with LAPS hot-start DI • 6-hour cycle • 27-hour forecasts • 12-km grid

10. MDSS modeling domain

11. Bulk statistics*State variables, 12-hr forecastsFeb 1 – Apr 8, 2003 *John Snook and Jared Seehafer

12. A closer look 9 pm model runs, verifying only Iowa stations, entire expt

13. MM5-Eta

14. MM5-AVN

15. RAMS-Eta

16. RAMS-AVN

17. WRF-Eta

18. WRF-AVN

19. Precipitation verification

20. Lessons learned • Model verification: • Some members are not helpful • If we can’t fix RAMS problems … • VaryingLBC models doesn’t add diversity (!) • Field experience: • Services should be optimized for 3-12 h forecasts • Emphasis during 2003 Demo was 12-24 h forecasts • Need outputs at 1-hr intervals • Better precip start/stop times

21. Improving the ensemble • Add good models • FSL/RUC will be included for Demo 2004 • Change ensemble configuration • Grid increment and domain okay • WRF cloud/precip physics, perhaps RAMS also • Initialize more often • Shorter forecasts • Improve post-processing • Better PoP (probability of precip) estimates -- FSL • Better tuning procedures -- NCAR • Hope for “better” weather during tuning period

22. 6 models, 4 per day, 27 h forecasts = 648 model-hours / day 3 h output = 240 frames / day to move to NCAR 2 models, 24 per day, 13 h forecasts = 624 model-hours / day 1 h output = 576 frames / day to move to NCAR Juggling act 2003 2004

23. Plan • Real-time runs starting 1 October • “training” period • Demo begins 1 January 2004 • Web displays • Model output • State-variable verification • Precip verification

24. Loops of the two different models initialized at the same time

25. Loops of the same model (WRF) initialized an hour apart

26. 4 forecasts valid at the same time