Effects of Synoptic Surveillance on model forecasts for
02 September 2004 0000 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 | 23 | 23 | 55 | 41 | 68 | 40 | 59 | 53 | 160 | 224
| AVNO | 31 | 69 | 52 | 86 | 101 | 170 | 253 | 361 | 387 | 567
| %IMP | -35% | -200% | 5% | -110% | -49% | -325% | -329% | -581% | -142% | -153%
|
| GFNO | 0 | 0 | 0 | 10 | 30 | 89 | 146 | 215 | 230 | 299
| GFDL | 33 | 52 | 46 | 46 | 67 | 136 | 184 | 293 | 344 | 392
| %IMP | und% | und% | und% | -360% | -123% | -53% | -26% | -36% | -50% | -31%
|
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -78 | -66 | -49 | -32 | -30 | -24 | -20 | 1 | -1 | 10
| AVNO | -62 | -49 | -24 | -4 | 0 | 0 | 0 | 27 | 11 | 23
| %IMP | 29% | 26% | 51% | 87% | 100% | 100% | 100% | -2600% | -1000% | -130%
|
| GFNO | -10 | 6 | 12 | 19 | 15 | 5 | 6 | 26 | 17 | 33
| GFDL | -14 | -7 | 8 | 19 | 12 | 8 | 9 | 26 | 23 | 28
| %IMP | -40% | -17% | 50% | 0% | 20% | -60% | -50% | 0% | -35% | 15%
|
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| 02/1930 UTC 24.0N 74.5W San Salvador Island, Bahamas 19.5 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 23.85 | 74.73 | 21.0 | 28.7 | San Salvador Island, Bahamas
| AVNO | 24.36 | 74.16 | 21.0 | 52.8 | Near San Salvador Island, Bahamas
| %IMP | 0% | -84%
|
| GFNO | 23.93 | 74.57 | 21.0 | 10.5 | San Salvador Island, Bahamas
| GFDL | 24.29 | 74.25 | 22.0 | 41.0 | San Salvador Island, Bahamas
| %IMP | -67% | -290%
|
|
03/0530 UTC 24.6N 75.6W Northern end of Cat Island, Bahamas 29.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.35 | 75.52 | 27.0 | 28.9 | Cat Island, Bahamas
| AVNO | 25.21 | 74.24 | 30.0 | 152.9 | Offshore Cat Island, Bahamas
| %IMP | 80% | -429%
|
| GFNO | 24.74 | 75.54 | 29.5 | 16.7 | Northern end of Cat Island, Bahamas
| GFDL | 25.10 | 75.28 | 29.5 | 64.2 | Near northern tip of Cat Island, Bahamas
| %IMP | 0% | -284%
|
03/1000 UTC 25.1N 76.1W Eleuthera Island, Bahamas 34.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 24.81 | 76.33 | 32.5 | 39.7 | Eleuthera Island, Bahamas
| AVNO | 25.69 | 76.03 | 37.5 | 65.9 | Near northern tip of Eleuthera Island, Bahamas
| %IMP | -133% | -66%
|
| GFNO | 25.34 | 76.36 | 36.5 | 37.3 | Eleuthera Island, Bahamas
| GFDL | 25.66 | 76.14 | 35.5 | 62.3 | Near northern tip of Eleuthera Island, Bahamas
| %IMP | 40% | -67%
|
|
04/1000 UTC 26.6N 78.2W Grand Bahama Island, Bahamas 58.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.30 | 78.90 | 60.0 | 77.2 | Near Grand Bahama Island, Bahamas
| AVNO | 26.57 | 77.03 | 53.0 | 116.3 | Abaco Island, Bahamas
| %IMP | -150% | -51%
|
| GFNO | 26.71 | 78.41 | 56.5 | 24.2 | Grand Bahama Island, Bahamas
| GFDL | 26.88 | 77.98 | 54.0 | 38.0 | Little Abaco Island, Bahamas
| %IMP | -167% | -57%
|
05/0430 UTC 27.2N 80.2W South end of Hutchinson Island, FL 76.5 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 27.04 | 80.12 | 74.5 | 19.5 | Jupiter, FL
| AVNO | 32.07 | 79.23 | 118.5 | 549.1 | Near Seabrook Island, SC
| %IMP | -2000% | -2716%
|
| GFNO | 30.12 | 81.34 | 103.0 | 342.9 | Palm Valley, FL
| GFDL | 31.86 | 80.76 | 118.5 | 520.5 | Tybee Island, GA
| %IMP | -71% | -52%
|
|
06/1800 UTC 30.1N 84.0W Mouth of Aucilla River, FL 114.0 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 02 September 2004 0000 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 0000 UTC.
Figure 3. NCEP Global Ensemble Predction System track forecasts for all cyclones in the Atlantic basin initialized from 31 August 2004 0600 UTC to 01 September 2004 0000 UTC, showing the tracks of Hurricane Frances.
Figure 4. Ensemble perturbation variance at the nominal sampling time 02 September 2004 0000 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 0000 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 0000 UTC. The circles represent the dropwindsonde locations.
