Effects of Synoptic Surveillance on model forecasts for
31 August 2004 0600 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 | 42 | 70 | 132 | 139 | 123 | 123 | 131 | 73 | 107 | 213
| AVNO | 25 | 15 | 21 | 20 | 52 | 78 | 96 | 73 | 145 | 228
| %IMP | 40% | 79% | 84% | 86% | 58% | 37% | 27% | 0% | -36% | -7%
|
| GFNO | 24 | 22 | 56 | 59 | 78 | 113 | 158 | 212 | 320 | 467
| GFDL | 25 | 22 | 23 | 44 | 78 | 133 | 178 | 255 | 422 | 603
| %IMP | -4% | 0% | 59% | 25% | 0% | -18% | -13% | -20% | -32% | -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 | -81 | -79 | -78 | -81 | -73 | -54 | -44 | -35 | -32 | -17
| AVNO | -74 | -75 | -70 | -77 | -63 | -38 | -26 | -16 | -9 | -12
| %IMP | 9% | 5% | 10% | 5% | 14% | 30% | 41% | 56% | 72% | 29%
|
| GFNO | -5 | -10 | -8 | -18 | -13 | -4 | -4 | 8 | 3 | 1
| GFDL | 0 | -2 | 1 | -16 | -14 | -8 | -6 | 6 | 8 | 5
| %IMP | 100% | 80% | 87% | 11% | -8% | -100% | -50% | 25% | 50% | -200%
|
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| 02/1930 UTC 24.0N 74.5W San Salvador Island, Bahamas 61.5 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.70 | 73.93 | 57.5 | 96.8 | Offshore San Salvador Island, Bahamas
| AVNO | 24.32 | 74.25 | 64.5 | 43.7 | Near San Salvador Island, Bahamas
| %IMP | 25% | 55%
|
| GFNO | 24.39 | 74.27 | 59.0 | 49.2 | Near San Salvador Island, Bahamas
| GFDL | 24.38 | 74.17 | 59.0 | 53.9 | Near San Salvador Island, Bahamas
| %IMP | 0% | -10%
|
|
03/0530 UTC 24.6N 75.6W Northern end of Cat Island, Bahamas 71.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 25.42 | 75.04 | 67.0 | 107.1 | Offshore Cat Island, Bahamas
| AVNO | 25.10 | 75.11 | 73.0 | 74.3 | Near Cat Island, Bahamas
| %IMP | 67% | 31%
|
| GFNO | 25.10 | 75.19 | 66.0 | 69.2 | Near Cat Island, Bahamas
| GFDL | 25.20 | 75.00 | 66.0 | 90.0 | Near Cat Island, Bahamas
| %IMP | 0% | -30%
|
|
03/1000 UTC 25.1N 76.1W Eleuthera Island, Bahamas 76.0 h into the forecast
| AVNN | 24.88 | 75.69 | 73.0 | 48.0 | Southern tip of Eleuthera Island, Bahamas
| AVNO | 25.58 | 75.66 | 78.0 | 69.3 | Near Eleuthera Island, Bahamas
| %IMP | 33% | -44%
|
| GFNO | 25.54 | 75.74 | 70.5 | 60.8 | Near Eleuthera Island, Bahamas
| GFDL | 25.67 | 75.46 | 70.0 | 90.2 | Near Eleuthera Island, Bahamas
| %IMP | -9% | -48%
|
|
|
04/1000 UTC 26.6N 78.2W Grand Bahama Island, Bahamas 100.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.98 | 77.55 | 95.5 | 77.1 | Little Abaco Island, Bahamas
| AVNO | 26.88 | 77.54 | 104.5 | 166.8 | Little Abaco Island, Bahamas
| %IMP | 0% | -116%
|
| GFNO | 26.70 | 76.65 | 80.5 | 204.2 | Abaco Island, Bahamas
| GFDL | 26.79 | 76.69 | 79.5 | 207.9 | Abaco Island, Bahamas
| %IMP | -5% | -2%
|
|
|
05/0430 UTC 27.2N 80.2W South end of Hutchinson Island, FL 118.5 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 156.0 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 | |
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Figure 1. NCEP 850 - 200 hPa mean wind analysis for 31 August 2004 0600 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 0600 UTC.
Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 31 August 2004 0600 UTC.
