Effects of Synoptic Surveillance on model forecasts for
14 September 1999 1800 UTC
FLOYD.
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 | 49. | 56. | 67. | 198.
| AVAL | 56. | 53. | 37. | 62.
| %IMP | -14% | 5% | 45% | 69%
|
| GFNO | 35. | 65. | 133. | 204. | 338. | 511. | 677. | 842. | 1099.
| GFAL | 23. | 49. | 98. | 175. | 339. | 511. | 662. | 849. | 1113.
| %IMP | 34% | 25% | 26% | 15% | 0% | 0% | 2% | -1% | -1%
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -63. | -46. | -42. | -9.
| AVAL | -24. | -16. | -25. | -11.
| %IMP | 62% | 65% | 40% | -22%
|
| GFNO | -3. | 8. | 4. | 16. | 16. | 10. | 16. | -9. | -9.
| GFAL | 1. | 11. | 0. | 15. | 12. | 6. | 11. | -11. | -9.
| %IMP | 67% | -38% | 100% | 6% | 25% | 40% | 31% | -22% | 0%
|
| SHNO | 0. | 8. | 5. | 28. | 36. | 40. | 52. | 55. | 58.
| SHAL | -1. | 6. | 2. | 26. | 34. | 37. | 49. | 53. | 56.
| %IMP | und% | 25% | 60% | 7% | 6% | 6% | 8% | 4% | 3%
|
| DSNO | 0. | 8. | -9. | -16. | -18. | -17. | -8. | -8. | -8.
| DSAL | -1. | 6. | -11. | -17. | -18. | -17. | -8. | -8. | -8.
| %IMP | und% | 25% | 60% | -6% | 0% | 0% | 0% | 0% | 0%
| | ||||||||||
| 16/0630 UTC 33.8N 78.0W Near Cape Fear, NC 36.5 h into the forecast | |||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 33.78 | 77.65 | 38.5 | 32.4 | Cape Fear, NC
| AVAL | 33.85 | 78.32 | 36.5 | 30.1 | Long Beach, NC
| %IMP | 100% | 7%
|
| GFNO | 33.35 | 79.25 | 36.5 | 125.0 | Georgetown, SC
| GFAL | 33.10 | 79.11 | 35.0 | 129.0 | Near Georgetown, SC
| %IMP | und% | -3%
| | ||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 14 September 1999 1800 UTC (Hurricane Floyd).
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 14 September 1999 1800 UTC. The best track is shown in black.
Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 14 September 1999 1800 UTC.
Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 14 September 1999 1800 UTC.