Effects of Synoptic Surveillance on model forecasts for
29 August 1999 0000 UTC
DENNIS.
QuickTime movie of DLM wind model forecasts
QuickTime movie of DLM wind data increments
| TRACK (km) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | No forecast available
| AVAL | No forecast available
| %IMP
|
| GFNO | 31. | 94. | 188. | 464. | 1120. | 1932.
| GFAL | 36. | 36. | 59. | 38. | 180. | 357.
| %IMP | -16% | 62% | 69% | 92% | 84% | 82%
|
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | No forecast available
| AVAL | No forecast available
| %IMP
|
| GFNO | 12. | 11. | 21. | 23. | 27. | 34.
| GFAL | 16. | 14. | 19. | 19. | 15. | 29.
| %IMP | -33% | -27% | 10% | 17% | 44% | 15%
|
| SHNO | No forecast available
| SHAL | No forecast available
| %IMP
|
| DSNO | No forecast available
| DSAL | No forecast available
| %IMP
| | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 04/2100UTC 34.8N 76.5W Cape Lookout National Seashore, NC 165 h into forecast | ||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | No landfall forecast
| AVAL | No landfall forecast
| %IMP
|
| GFNO | No landfall forecast
| GFAL | No landfall forecast
| %IMP
|
| | ||||||||||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 29 August 1999 0000 UTC (Hurricane Dennis).
Figure 2. Track forecasts for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the AVN and GFDL models initialized on 29 August 1999 0000 UTC. The best track is shown in black.
Figure 3. Ensemble perturbation variance at the nominal sampling time 29 August 1999 0000 UTC from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.
Figure 4. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 29 August 1999 0000 UTC. The green circles represent the dropwindsonde locations.
