Effects of Synoptic Surveillance on model forecasts for
25 August 1999 0600 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 | 189. | 175. | 129. | 74. | 40. | 105. | 148. | 214. | 260. | 380.
| AVAL | 69. | 54. | 67. | 52. | 73. | 173. | 211. | 297. | 335. | 437.
| %IMP | 22% | 69% | 48% | 30% | -83% | -65% | -43% | -39% | -29% | -15%
|
| GFNO | 189. | 265. | 342. | 392. | 485. | 635. | 953. | 1395. | 2047.
| GFAL | 153. | 194. | 213. | 201. | 230. | 267. | 392. | 611. | 908.
| %IMP | 19% | 17% | 38% | 49% | 53% | 58% | 59% | 56% | 56%
|
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -33. | -46. | -48. | -40. | -39. | -48. | -61. | -60. | -58. | -56.
| AVAL | -29. | -41. | -44. | -37. | -37. | -50. | -61. | -59. | -53. | -53.
| %IMP | 12% | 11% | 8% | 8% | 5% | -4% | 0% | 2% | 9% | 5%
|
| GFNO | -17. | -13. | -10. | -8. | 12. | 17. | 2. | -6. | -38.
| GFAL | -16. | -15. | 3. | 20. | 17. | 14. | 4. | 16. | 4.
| %IMP | 6% | -15% | 70% | -150% | -42% | 18% | -100% | -167% | 89%
|
| SHNO | -10. | -13. | -10. | 1. | 7. | -1. | -14. | -14. | -15. | -15.
| SHAL | -10. | -14. | -11. | 0. | 5. | -3. | -16. | -16. | -16. | -17.
| %IMP | 0% | -8% | -10% | 100% | 29% | -200% | -14% | -14% | -7% | -13%
|
| DSNO | -10. | -13. | -10. | 1. | 7. | -1. | -14. | -14. | -15. | -15.
| DSAL | -10. | -14. | -11. | 0. | 5. | -3. | -16. | -16. | -16. | -17.
| %IMP | 0% | -8% | -10% | 100% | 29% | -200% | -14% | -14% | -7% | -13%
| | ||||||||||
| 28/0700UTC 26.6N 76.8W Abaco Islands, Bahamas 73 h into forecast | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.11 | 77.18 | 67.5 | 66.3 | Crossing Rocks, Abaco Island, Bahama Islands
| AVAL | 26.52 | 78.66 | 97.5 | 185.1 | Freeport, Grand Bahama Island, Bahama Islands
| %IMP | -345% | -179%
|
| GFNO | 24.33 | 74.34 | 15.0 | 352.8 | Cockburn Town, San Salvador, Bahama Islands
| GFAL | 26.74 | 77.17 | 54.0 | 39.9 | Great Guana Cay, Abaco Island, Bahama Islands
| %IMP | 67% | 89%
|
|
|
04/2100UTC 34.8N 76.5W Cape Lookout National Seashore, NC 255 h into forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | No landfall forecast
| AVAL | No landfall forecast
| %IMP
|
| GFNO | 34.74 | 76.51 | 80.0 | 6.7 | Marshallburg, NC
| GFAL | 34.18 | 77.81 | 95.0 | 138.3 | Masonboro, NC
| %IMP | 9% | -1964%
| | |||||||||||||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 25 August 1999 0600 UTC (Tropical Storm 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 25 August 1999 0600 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 25 August 1999 0600 UTC.
