Effects of Synoptic Surveillance on model forecasts for
31 August 2004 1200 UTC
Frances.
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 | 46 | 67 | 111 | 193 | 191 | 152 | 170 | 134 | 157 | 178
| AVNO | 56 | 67 | 88 | 123 | 127 | 143 | 149 | 113 | 119 | 174
| %IMP | -22% | 0% | 21% | 36% | 34% | 6% | 12% | 16% | 24% | 2%
|
| GFNO | 24 | 54 | 84 | 122 | 161 | 179 | 258 | 334 | 503 | 673
| GFDL | 25 | 54 | 103 | 151 | 188 | 206 | 273 | 338 | 496 | 658
| %IMP | 4% | 0% | -23% | -24% | -17% | -15% | -6% | -1% | 1% | 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 | -83 | -81 | -78 | -81 | -67 | -49 | -35 | -35 | -28 | -16
| AVNO | -73 | -75 | -72 | -78 | -64 | -47 | -26 | -29 | -24 | -3
| %IMP | 12% | 7% | 8% | 4% | 4% | 4% | 26% | 17% | 14% | 81%
|
| GFNO | 4 | 3 | 4 | -14 | -8 | -6 | 5 | 6 | 2 | 0
| GFDL | -5 | -4 | -2 | -17 | -14 | -7 | 2 | -1 | 1 | 2
| %IMP | -25% | -67% | 50% | -21% | -75% | -17% | 60% | 83% | 50% | und%
|
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| 02/1930 UTC 24.0N 74.5W San Salvador Island, Bahamas 55.5 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 25.15 | 73.36 | 50.5 | 172.0 | Offshore San Salvador Island, Bahamas
| AVNO | 24.81 | 73.78 | 57.5 | 115.8 | Offshore San Salvador Island, Bahamas
| %IMP | 60% | 33%
|
| GFNO | 24.83 | 73.69 | 53.5 | 123.4 | Offshore San Salvador Island, Bahamas
| GFDL | 24.98 | 73.45 | 53.0 | 152.1 | Offshore San Salvador Island, Bahamas
| %IMP | -20% | -23%
|
|
03/0530 UTC 24.6N 75.6W Northern end of Cat Island, Bahamas 65.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 25.15 | 73.36 | 50.5 | 233.9 | Offshore San Salvador Island, Bahamas
| AVNO | 25.58 | 74.63 | 67.0 | 146.2 | Offshore Eleuthera Island, Bahamas
| %IMP | 90% | 37%
|
| GFNO | 25.71 | 74.63 | 61.0 | 157.2 | Offshore Eleuthera Island, Bahamas
| GFDL | 24.98 | 73.45 | 53.0 | 220.9 | Offshore San Salvador Island, Bahamas
| %IMP | -178% | -41%
|
|
03/1000 UTC 25.1N 76.1W Eleuthera Island, Bahamas 70.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 27.52 | 77.19 | 92.5 | 289.9 | Near Grand Cay, Bahamas
| AVNO | 26.30 | 75.49 | 76.0 | 65.2 | Offshore Abaco Island, Bahamas
| %IMP | 73% | 78%
|
| GFNO | 26.31 | 75.41 | 66.5 | 151.1 | Offshore Abaco Island, Bahamas
| GFDL | 27.31 | 76.01 | 74.0 | 245.7 | Offshore Abaco Island, Bahamas
| %IMP | -14% | -63%
|
|
04/1000 UTC 26.6N 78.2W Grand Bahama Island, Bahamas 94.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 27.52 | 77.19 | 92.5 | 245.9 | Near Grand Cay, Bahamas
| AVNO | 27.26 | 77.40 | 95.0 | 108.0 | Little Abaco Island, Bahamas
| %IMP | 33% | 56%
|
| GFNO | 27.07 | 76.25 | 73.5 | 200.2 | Near Abaco Island, Bahamas
| GFDL | 27.31 | 76.01 | 74.0 | 230.8 | Offshore Abaco Island, Bahamas
| %IMP | 2% | -15%
|
|
05/0430 UTC 27.2N 80.2W South end of Hutchinson Island, FL 112.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | No landfall forecast
| AVNO | No landfall forecast
| %IMP | |
|
| GFNO | 33.05 | 79.55 | 117.5 | 652.9 | McClellanville, SC
| GFDL | 33.13 | 79.31 | 119.0 | 664.3 | McClellanville, SC
| %IMP | -30% | -2%
|
|
06/1800 UTC 30.1N 84.0W Mouth of Aucilla River, FL 150.0 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 31 August 2004 1200 UTC (Hurricane Frances).
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 31 August 2004 1200 UTC.
Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 31 August 2004 1200 UTC.
