1. COSMIC Retreat 2008 Impact of COSMIC on typhoon prediction Bill Kuo and Ted Iwabuchi

2. Historical Typhoon Tracks Inter-annual variations of typhoon path and activity It’s clear that we need observation over the ocean 2004 29 2005 23 2006 23 2007 24

3. Typhoon Paths in 2008 17 typhoons in 2008 (by Oct 9)

4. Typhoon Landfalls in Taiwan in 2008 Three typhoons have landfalled in Taiwan in 2008 How is relative importance of COSMIC data ?

5. Real-time Typhoon Forecast Design Cold 3DVAR: 6 hour DA time windows at 00 UTC Cycling 3DVAR: 3 hour DA time window every 3 hours from 00UTC for 24 hour time windows

6. Real-time Typhoon Forecast Design COSMIC + Conventional vs only Conventional (w/o COSMIC) Cold 3DVAR vs Cycling 3DVAR Conventional data (SYNOP, SHIP, BUOY, METAR, PILOT, SOUND, AMDAR, SATEM, SATOB, GPSPW, AIREP, PROFL)

7. COSMIC Profile Availability COSMIC data is available continuously –Not like radiosonde data available only at 00 and 12Z Cycling 3DVAR for long data assimilation time window is one of the optimal assimilation scheme for COSMIC DA 22.5-1.51.5-4.54.5-7.57.5-10.5 10.5-13.513.5-16.516.5-19.519.5-22.5 22.5-1.5 (+1d) DAtime window: 09-25_00Z - 09-26_00Z

8. Cold 3DVAR vs Cycling 3DVAR Significant improvement for track forecast in cycling 3DVAR Cold 3DVARCycling 3DVAR IC: 2008-09-25_00Z

9. Track Forecast Errors Cycling 3DVAR forecast is much better than cold 3DVAR forecast Forecast with COSMIC profile is better than that without COSMIC profile Cold 3DVAR Cycling 3DVAR COSMIC IC: 2008-09-25_00Z

10. Intensity Forecast Comparison Gaps between best track from JMA and WRF forecast Trend of intensity changes is more similar in cycling 3DVAR forecast than those in cold 3DVAR forecast

11. Typhoon Real-time Forecast with COSMIC Real-time and continuous ingestion of COSMIC profile helped to forecast typhoon Jangmi We need more test case studies for statistical discussions We need to mprove intensity forecasts

12. Landfall of Jangmi to Taiwan

13. Cold 3DVAR vs Cycling 3DVAR Significant improvement for track forecast in cycling 3DVAR and COSMIC IC: 2008-09-26_00Z Cold 3DVARCycling 3DVAR

14. Track Forecast Errors Significant improvement for track forecast with COSMIC cycling DA IC: 2008-09-26_00Z

15. Intensity Forecast Comparison

16. Cold 3DVAR vs Cycling 3DVAR Significant improvement for track forecast in cycling 3DVAR and COSMIC IC: 2008-09-10_00Z Cold 3DVARCycling 3DVAR

17. Track Forecast Errors Significant improvement for track forecast with COSMIC cycling DA IC: 2008-09-10_00Z

18. Intensity Forecast Comparison

19. Summary and Discussions Cycling 3DVAR DA can get maximum benefit of COSMIC data –Not like radiosonde only at 00 and 12Z Positive impact for track forecast continue more than 3 days –Improvement of environment around typhoon path ? More COSMIC profile should be helpful for forecast of tropical cyclone More intensity is needed for short-tern forecast –Longer DA time window? Which is important: number of data or number of cycling ?