Effects of Synoptic Surveillance on model forecasts for
25 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 | 153. | 185. | 199. | 116. | 93. | 90. | 163. | 201. | 255. | 370.
| AVAL | 46. | 67. | 75. | 40. | 90. | 151. | 260. | 349. | 393. | 435.
| %IMP | 70% | 64% | 62% | 66% | 3% | -68% | -60% | -74% | -54% | -18%
|
| GFNO | 121. | 168. | 193. | 216. | 214. | 299. | 401. | 618. | 948. | 1313.
| GFAL | 111. | 153. | 211. | 229. | 231. | 323. | 436. | 689. | 987. | 1284.
| %IMP | 8% | 9% | -9% | -6% | -8% | -8% | -9% | -11% | -4% | 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 | -24. | -40. | -42. | -42. | -38. | -45. | -55. | -59. | -59. | -57.
| AVAL | -23. | -35. | -37. | -39. | -35. | -41. | -54. | -55. | -54. | -52.
| %IMP | 4% | 13% | 12% | 7% | 8% | 9% | 2% | 7% | 8% | 9%
|
| GFNO | -1. | 16. | 17. | 15. | 26. | 35. | 24. | 24. | 10. | -4.
| GFAL | -2. | 8. | -6. | 4. | 14. | 16. | 24. | 8. | -5. | -27.
| %IMP | -100% | 50% | 65% | 73% | 46% | 54% | 0% | 67% | 50% | -575%
|
| SHNO | 4. | -3. | -1. | 4. | 8. | 3. | -11. | -18. | -19. | -20.
| SHAL | 4. | -3. | -1. | 3. | 8. | 2. | -12. | -19. | -20. | -20.
| %IMP | 0% | 0% | 0% | 25% | 0% | 33% | -9% | -6% | -5% | 0%
|
| DSNO | 4. | -3. | -1. | 4. | 8. | 3. | -11. | -18. | -19. | -20.
| DSAL | 4. | -3. | -1. | 3. | 8. | 2. | -12. | -19. | -20. | -20.
| %IMP | 0% | 0% | 0% | 25% | 0% | 33% | -9% | -6% | -5% | 0%
| | ||||||||||
| 28/0700UTC 26.6N 76.8W Abaco Islands, Bahamas 79 h into forecast | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.00 | 77.18 | 73.0 | 76.7 | Sandy Point, Abaco Island, Bahama Islands
| AVAL | 25.00 | 76.15 | 60.5 | 189.3 | Tarpum Bay, Eleuthera Island, Bahama Islands
| %IMP | -208% | -147%
|
| GFNO | 24.21 | 74.44 | 27.5 | 355.8 | Cockburn Town, San Salvador, Bahama Islands
| GFAL | 26.42 | 77.06 | 56.0 | 32.7 | Cherokee Sound, Abaco Island, Bahama Islands
| %IMP | 55% | 91%
|
|
|
04/2100UTC 34.8N 76.5W Cape Lookout National Seashore, NC 261 h into forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | No landfall forecast
| AVAL | No landfall forecast
| %IMP
|
| GFNO | 34.92 | 76.31 | 99.5 | 21.9 | Atlantic, NC
| GFAL | 33.99 | 78.12 | 94.5 | 173.7 | Long Beach, NC
| %IMP | -3% | -693%
| | |||||||||||||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 25 August 1999 0000 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 0000 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 0000 UTC.
