Effects of Synoptic Surveillance on model forecasts for
14 September 1999 1200 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 | 45. | 81. | 61. | 42. | 65. | 325. | 569. | 667. | 776. | 571.
| AVAL | 23. | 56. | 22. | 72. | 98. | 201. | 443. | 487. | 490. | 371.
| %IMP | 49% | 31% | 64% | -71% | -51% | 38% | 22% | 27% | 37% | 35%
|
| GFNO | 30. | 44. | 87. | 151. | 258. | 385. | 482. | 627. | 865. | 1216.
| GFAL | 30. | 29. | 61. | 146. | 274. | 453. | 553. | 753. | 884. | 1236.
| %IMP | 0% | 34% | 30% | 3% | -6% | -18% | -15% | -20% | -2% | -2%
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -69. | -52. | -41. | -21. | -1. | -3. | 1. | -3. | 10. | -1.
| AVAL | -33. | -33. | -25. | -8. | 2. | -2. | -4. | 2. | 4. | 0.
| %IMP | 52% | 37% | 39% | 62% | -100% | 33% | -300% | 33% | 60% | 100%
|
| GFNO | -5. | 9. | 9. | 15. | 21. | 15. | 15. | -6. | -11. | -8.
| GFAL | -3. | 10. | 11. | 7. | 14. | 10. | 11. | -6. | -5. | -8.
| %IMP | 40% | -11% | -22% | 53% | 33% | 33% | 27% | 0% | 55% | 0%
|
| SHNO | 8. | 16. | 17. | 27. | 43. | 42. | 48. | 56. | 58. | 53.
| SHAL | 8. | 15. | 16. | 27. | 43. | 42. | 47. | 55. | 57. | 52.
| %IMP | 0% | 6% | 6% | 0% | 0% | 2% | 2% | 2% | 2% | 2%
|
| DSNO | 8. | 16. | 17. | -7. | -12. | -15. | -12. | -8. | -8. | -13.
| DSAL | 8. | 15. | 16. | -7. | -12. | -15. | -12. | -8. | -8. | -13.
| %IMP | 0% | 6% | 6% | 0% | 0% | 0% | 0% | 0% | 0% | 0%
| | ||||||||||
| 14/1900 UTC 26.3N 77.1W Near Cherokee Sound, Abaco 7 h into the forecast | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.85 | 77.67 | 13.0 | 83.3 | Abaco, Bahamas
| AVAL | 26.67 | 77.31 | 10.5 | 46.1 | Abaco Island, Bahamas
| %IMP | 42% | 45%
|
| GFNO | 26.90 | 77.90 | 12.0 | 103.7 | Abaco Island, Bahamas
| GFAL | 26.90 | 77.90 | 12.0 | 103.7 | Abaco Island, Bahamas
| %IMP | 0% | 0% |
|
|
16/0630 UTC 33.8N 78.0W Near Cape Fear, NC 42.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 34.95 | 76.91 | 47.0 | 161.7 | Emerald Isle, NC
| AVAL | 33.88 | 77.87 | 44.0 | 14.9 | Cape Fear, NC
| %IMP | 67% | 91%
|
| GFNO | 33.13 | 79.14 | 41.5 | 129.2 | Quarantine, SC
| GFAL | 33.58 | 79.03 | 42.0 | 98.3 | Garden City, SC
| %IMP | 50% | 24%
| | |||||||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 14 September 1999 1200 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 1200 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 1200 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 1200 UTC.