Effects of Synoptic Surveillance on model forecasts for
02 September 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 | 87 | 73 | 100 | 90 | 72 | 50 | 29 | 22 | 102
| AVNO | 23 | 20 | 30 | 40 | 30 | 33 | 80 | 91 | 78 | 168
| %IMP | 50% | 77% | 59% | 60% | 67% | 54% | -60% | -214% | -255% | -65%
|
| GFNO | 20 | 20 | 30 | 32 | 67 | 94 | 145 | 149 | 138 | 267
| GFDL | 20 | 20 | 40 | 60 | 60 | 30 | 78 | 48 | 59 | 168
| %IMP | 0% | 0% | -67% | -88% | 10% | 68% | 46% | 68% | 57% | 37%
|
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -62 | -49 | -31 | -29 | -28 | -24 | -3 | -17 | -2 | -4
| AVNO | -37 | -30 | -6 | -13 | -13 | -14 | 1 | -13 | -3 | -7
| %IMP | 30% | 38% | 81% | 55% | 54% | 42% | 67% | 24%- | 50% | -75%
|
| GFNO | -3 | 7 | 22 | 19 | 6 | 8 | 31 | 16 | 11 | 10
| GFDL | 2 | 17 | 30 | 22 | 16 | 12 | 26 | 9 | 14 | 17
| %IMP | 33% | -143% | -36% | -16% | -167% | -50% | 16% | 44% | -27% | -70%
|
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| 02/1930 UTC 24.0N 74.5W San Salvador Island, Bahamas 7.5 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 23.75 | 74.81 | 9.5 | 42.0 | Rum Cay, Bahamas
| AVNO | 23.78 | 74.72 | 9.0 | 33.1 | Rum Cay, Bahamas
| %IMP | 25% | 21%
|
| GFNO | 23.84 | 74.59 | 8.0 | 20.0 | Rum Cay, Bahamas
| GFDL | 23.82 | 74.61 | 8.0 | 22.9 | Rum Cay, Bahamas
| %IMP | 0% | -15%
|
|
03/0530 UTC 24.6N 75.6W Northern end of Cat Island, Bahamas 17.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.13 | 75.55 | 13.5 | 52.5 | Southern end of Eleuthera Island, Bahamas
| AVNO | 24.54 | 75.58 | 16.0 | 7.0 | Cat Island, Bahamas
| %IMP | 62% | 87%
|
| GFNO | 24.57 | 75.59 | 16.0 | 3.5 | Cat Island, Bahamas
| GFDL | 24.68 | 75.69 | 17.0 | 12.7 | Cat Island, Bahamas
| %IMP | 67% | -263%
|
03/1000 UTC 25.1N 76.1W Eleuthera Island, Bahamas 22.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.51 | 76.27 | 18.0 | 67.8 | Southern end of Eleuthera Island, Bahamas
| AVNO | 25.05 | 76.16 | 21.0 | 8.2 | Eleuthera Island, Bahamas
| %IMP | 75% | 88%
|
| GFNO | 24.99 | 76.12 | 20.5 | 12.4 | Eleuthera Island, Bahamas
| GFDL | 25.05 | 76.15 | 21.0 | 7.5 | Eleuthera Island, Bahamas
| %IMP | 33% | 40%
|
|
04/1000 UTC 26.6N 78.2W Grand Bahama Island, Bahamas 46.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.18 | 78.95 | 43.5 | 88.0 | Near Grand Bahama Island, Bahamas
| AVNO | 26.56 | 78.52 | 43.5 | 32.1 | Grand Bahama Island, Bahamas
| %IMP | 0% | 64%
|
| GFNO | 26.52 | 78.37 | 43.0 | 19.1 | Grand Bahama Island, Bahamas
| GFDL | 26.41 | 78.82 | 46.0 | 65.2 | Grand Bahama Island, Bahamas
| %IMP | 100% | -241%
|
05/0430 UTC 27.2N 80.2W South end of Hutchinson Island, FL 64.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.83 | 80.04 | 55.5 | 44.1 | Riviera Beach, FL
| AVNO | 27.23 | 80.23 | 65.5 | 11.5 | Port St. Lucie, FL
| %IMP | 89% | 74%
|
| GFNO | 28.37 | 80.58 | 73.0 | 135.2 | Cocoa Beach, FL
| GFDL | 27.12 | 80.14 | 60.5 | 10.7 | Port Salerno, FL
| %IMP | 53% | 92%
|
|
06/1800 UTC 30.1N 84.0W Mouth of Aucilla River, FL 102.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 30.07 | 84.17 | 99.0 | 16.7 | Wakulla Beach, FL
| AVNO | No landfall forecast
| %IMP | |
|
| GFNO | No landfall forecast
| GFDL | 30.07 | 84.07 | 97.5 | 7.5 | St. Marks, FL
| %IMP | |
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Figure 1. NCEP 850 - 200 hPa mean wind analysis for 02 September 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 02 September 2004 1200 UTC.
Figure 3. NCEP Global Ensemble Predction System track forecasts for all cyclones in the Atlantic basin initialized from 31 August 2004 1800 UTC to 01 September 2004 1200 UTC, showing the tracks of Hurricane Frances.
Figure 4. Ensemble perturbation variance at the nominal sampling time 02 September 2004 1200 UTC from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.
Figure 5. Variance explained within the verification region (large red circle) for observations taken at the sampling time 02 September 2004 1200 UTC from the Ensemble Transform Kalman Filter run from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.
Figure 6. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 02 September 2004 1200 UTC. The circles represent the dropwindsonde locations.
