Effects of Synoptic Surveillance on model forecasts for
29 August 2004 1800 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 | 100 | 137 | 177 | 133 | 111 | 88 | 93 | 136 | 144 | 146
| AVNO | 94 | 150 | 191 | 156 | 189 | 133 | 132 | 147 | 200 | 215
| %IMP | 6% | -9% | -8% | -17% | -70% | -51% | -42% | -8% | -39% | -47%
|
| GFNO | 71 | 79 | 69 | 63 | 83 | 137 | 153 | 167 | 189 | 246
| GFDL | 54 | 88 | 88 | 77 | 63 | 106 | 108 | 117 | 129 | 167
| %IMP | 24% | -11% | -28% | -22% | 24% | 23% | 29% | 30% | 32% | 32%
|
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -70 | -72 | -71 | -82 | -78 | -75 | -79 | -70 | -54 | -45
| AVNO | -69 | -74 | -72 | -82 | -81 | -77 | -83 | -73 | -59 | -48
| %IMP | 1% | -2% | -1% | 0% | -3% | -3% | -5% | -4% | -9% | -7%
|
| GFNO | 3 | 3 | 11 | 3 | -1 | -8 | -23 | -24 | -16 | -12
| GFDL | 0 | 2 | 12 | -1 | -8 | -7 | -32 | -29 | -15 | -13
| %IMP | 0% | 50% | -9% | 67% | -700% | 13% | -39% | -21% | 6% | -8%
|
| | ||||||||||
| 02/1930 UTC 24.0N 74.5W San Salvador Island, Bahamas 97.5 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.00 | 74.50 | 108.0 | 0.0 | San Salvador Island, Bahamas
| AVNO | 22.98 | 74.27 | 103.0 | 115.7 | Acklins Island, Bahamas
| %IMP | 48% | und%
|
| GFNO | 25.54 | 74.67 | 98.5 | 172.0 | Well offshore Cat Island, Bahamas
| GFDL | 24.29 | 74.35 | 92.0 | 35.6 | San Salvador Island, Bahamas
| %IMP | -450% | 79%
|
|
03/0530 UTC 24.6N 75.6W Northern end of Cat Island, Bahamas 107.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.77 | 75.66 | 117.0 | 19.8 | Cat Island, Bahamas
| AVNO | 23.19 | 75.06 | 110.5 | 166.0 | Long Island, Bahamas
| %IMP | 68% | -738%
|
| GFNO | 26.21 | 75.49 | 106.0 | 179.2 | Well offshore Eleuthera Island, Bahamas
| GFDL | 25.43 | 75.75 | 104.0 | 93.4 | Near Eleuthera Island, Bahamas
| %IMP | -133% | 48%
|
|
03/1000 UTC 25.1N 76.1W Eleuthera Island, Bahamas 112.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.77 | 75.66 | 117.0 | 57.5 | Cat Island, Bahamas
| AVNO | 23.48 | 75.52 | 115.0 | 189.3 | Near George Town, Exuma Island, Bahamas
| %IMP | 40% | -403%
|
| GFNO | 27.04 | 76.32 | 114.0 | 216.6 | Near Abaco Island, Bahamas
| GFDL | 26.66 | 76.79 | 116.0 | 186.5 | Abaco Island, Bahama
| %IMP | -200% | 14%
|
|
04/1000 UTC 26.6N 78.2W Grand Bahama Island, Bahamas 136.0 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 | |
|
|
05/0430 UTC 27.2N 80.2W South end of Hutchinson Island, FL 154.5 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 | |
|
|
06/1800 UTC 30.1N 84.0W Mouth of Aucilla River, FL 192.0 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 29 August 2004 1800 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 29 August 2004 1800 UTC.
Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 29 August 2004 1800 UTC.
