Effects of Synoptic Surveillance on model forecasts for
07 September 2004 1800 UTC
Ivan.
Quicktime movie of AVN DLM wind model
forecast
Quicktime movie of DLM wind data
increment
| TRACK (km) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | 39 | 108 | 142 | 146 | 172 | 223 | 279 | 317 | 364 | 491
| AVNO | 35 | 32 | 73 | 171 | 178 | 287 | 368 | 435 | 530 | 713
| %IMP | 10% | 70% | 49% | -17% | -3% | -29% | -32% | -37% | -46% | -45%
|
| GFNO | 131 | 181 | 247 | 278 | 346 | 363 | 419 | 483 | 584 | 735
| GFDL | 77 | 79 | 104 | 148 | 233 | 256 | 293 | 335 | 432 | 519
| %IMP | 41% | 56% | 58% | 47% | 33% | 29% | 30% | 31% | 26% | 29%
|
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -85 | -85 | -100 | -92 | -85 | -82 | -92 | -103 | -87 | -87
| AVNO | -67 | -64 | -90 | -77 | -70 | -69 | -76 | -90 | -87 | -82
| %IMP | 21% | 25% | 10% | 16% | 17% | 16% | 18% | 13% | 0% | 6%
|
| GFNO | 3 | 0 | -16 | -8 | -23 | -31 | -41 | -62 | -48 | -44
| GFDL | -7 | 7 | -24 | -8 | -7 | -11 | -29 | -43 | -37 | -38
| %IMP | -133% | und% | -50% | 0% | 70% | 65% | 29% | 31% | 23% | 14%
|
| | ||||||||||
| 07/2130 UTC 11.9N 61.8W 6 n mi SW of Prickly Point, Grenada 3.5 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 11.83 | 61.73 | 2.5 | 10.9 | St. George's, Grenada
| AVNO | 11.76 | 61.69 | 2.5 | 19.6 | St. George's, Grenada
| %IMP | 0% | -80%
|
| GFNO | 11.90 | 61.79 | 6.0 | 1.1 | St. George's, Grenada
| GFDL | 11.78 | 61.84 | 4.5 | 14.0 | St. George's, Grenada
| %IMP | 60% | -1173%
|
|
11/0330 UTC 17.4N 77.2W 20 n mi S of Portland Point, Jamaica 81.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 18.25 | 76.25 | 99.0 | 137.9 | Boston Bay, Jamaica
| AVNO | 18.30 | 74.50 | 88.5 | 302.5 | Les Anglais, Haiti
| %IMP | 60% | -119%
|
| GFNO | 18.20 | 72.12 | 57.5 | 544.7 | Belle-Anse, Haiti
| GFDL | 18.31 | 74.48 | 64.0 | 304.9 | Les Anglais, Haiti
| %IMP | 27% | 44%
|
|
12/1415 UTC 18.9N 81.5W 22 n mi SSW of Georgetown, Grand Cayman Island 116.25 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | No landfall forecast
| AVNO | 18.30 | 74.50 | 88.5 | 740.1 | Les Anglais, Haiti
| %IMP | |
|
| GFNO | 18.20 | 72.12 | 57.5 | 991.0 | Belle-Anse, Haiti
| GFDL | 18.31 | 74.48 | 64.0 | 742.1 | Les Anglais, Haiti
| %IMP | 11% | 25%
|
|
14/0100 UTC 21.7N 85.2W 15 n mi SW of Cabo San Antonio, Cuba 151.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | No landfall forecast
| AVNO | 19.87 | 75.53 | 103.0 | 1024.8 | Santiago de Cuba, Santiago de Cuba, Cuba
| %IMP | |
|
| GFNO | 19.99 | 74.86 | 73.0 | 1090.3 | Vateras, Guantanamo, Cuba
| GFDL | 19.82 | 77.69 | 81.5 | 807.7 | Near Niquero, Granma, Cuba
| %IMP | 11% | 26%
|
|
16/0650 UTC 30.2N 87.9W Near Pine Beach, AL 210.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | No landfall forecast
| AVNO | No landfall forecast
| %IMP | |
|
| GFNO | No landfall forecast
| GFDL | No landfall forecast
| %IMP |
| | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 07 September 2004 1800 UTC (Hurricane Ivan).
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 07 September 2004 1800 UTC.
Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 07 September 2004 1800 UTC.
Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 07 September 2004 1800 UTC.