Effects of Synoptic Surveillance on model forecasts for
25 August 2005 0000 UTC
Katrina.
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 | 83 | 171 | 274 | 318 | 330 | 451 | 535 | 724 | 757 | 786
| AVNO | 67 | 141 | 275 | 272 | 310 | 445 | 507 | 664 | 651 | 723
| %IMP | 19% | 18% | 0% | 14% | 6% | 1% | 5% | 8% | 14% | 8%
|
| GFNO | 68 | 160 | 252 | 322 | 344 | 366 | 417 | 493 | 480 | 459
| GFDL | 55 | 160 | 241 | 286 | 322 | 311 | 349 | 396 | 363 | 331
| %IMP | 19% | 0% | 4% | 11% | 6% | 15% | 16% | 20% | 24% | 28%
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -31 | -41 | -47 | -63 | -72 | -77 | -121 | -114 | -84 | -23
| AVNO | -31 | -44 | -48 | -63 | -73 | -74 | -118 | -114 | -85 | -21
| %IMP | 0% | -7% | -2% | 0% | -1% | 4% | 0% | 4% | 1% | 9%
|
| GFNO | 4 | -2 | 11 | 11 | -12 | -1 | -52 | -49 | -26 | -8
| GFDL | 6 | 4 | 23 | 19 | 14 | 13 | -36 | -34 | -8 | 3
| %IMP | -50% | -100% | -109% | -73% | -17% | -1200% | 31% | 31% | 69% | 62%
| | ||||||||||
| 25/2230 UTC 26.0N 80.1W at Broward/Miami-Dade County line, FL 22.5 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.13 | 80.12 | 43.5 | 14.6 | Fort Lauderdale, FL
| AVNO | 26.68 | 80.03 | 37.5 | 76.0 | West Palm Beach, FL
| %IMP | 29% | -421%
|
| GFNO | 25.32 | 80.30 | 49.0 | 78.1 | Homestead, FL
| GFDL | 25.00 | 80.54 | 48.5 | 119.5 | Plantation Key, FL
| %IMP | 2% | -53%
|
|
29/1110 UTC 29.3N 89.6W Near Buras, LA 107.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 28.81 | 82.63 | 91.0 | 679.1 | Homosassa, FL
| AVNO | 28.90 | 82.70 | 96.0 | 671.3 | Crystal River, FL
| %IMP | 31% | 1%
|
| GFNO | 29.80 | 84.66 | 105.0 | 480.7 | Carrabelle, FL
| GFDL | 30.26 | 85.91 | 109.0 | 371.5 | Panama City, FL
| %IMP | 50% | 23%
|
29/1445 UTC 30.2N 89.6W Near LA/MS border 110.75 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 28.81 | 82.63 | 91.0 | 691.4 | Homosassa, FL
| AVNO | 28.90 | 82.70 | 96.0 | 682.3 | Crystal River, FL
| %IMP | 25% | 1%
|
| GFNO | 29.80 | 84.66 | 105.0 | 477.4 | Carrabelle, FL
| GFDL | 30.26 | 85.91 | 109.0 | 354.3 | Panama City, FL
| %IMP | 70% | 26%
| | ||||||||||||||||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 25 August 2005 0000 UTC (Tropical Storm Katrina).
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 25 August 2005 0000 UTC.
Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 23 August 2005 0600 UTC to 24 August 2005 0000 UTC, showing the tracks of Tropical Storm Katrina.
Figure 4. Ensemble perturbation variance at the nominal sampling time 25 August 2005 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 25 August 2005 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. Adjoint-Derived Steering Sensitivity Vector for observations taken at the sampling time 25 August 2005 0000 UTC. The green circles represent the dropwindsonde locations.
Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 25 August 2005 0000 UTC. The green circles represent the dropwindsonde locations.
Figure 8. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 25 August 2005 0000 UTC. The circles represent the dropwindsonde locations.
