Effects of Synoptic Surveillance on model forecasts for
21 September 1999 0000 UTC
HARVEY.
QuickTime movie of DLM wind model forecasts
QuickTime movie of DLM wind data increments
| TRACK (km) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | No forecast available
| AVAL | No forecast available
| %IMP
|
| GFNO | 124. | 169.
| GFAL | 132. | 167.
| %IMP | -6% | 1%
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | No forecast available
| AVAL | No forecast available
| %IMP
|
| GFNO | 16. | 45.
| GFAL | 15. | 41.
| %IMP | 6% | 9%
|
| SHNO | 5. | 16.
| SHAL | 5. | 16.
| %IMP | 0% | 0%
|
| DSNO | -7. | 2.
| DSAL | -7. | 2.
| %IMP | 0% | 0%
| | ||||||||||||||||||||||||||||||||||||||||||||||
| 21/1700 UTC 25.9N 81.7W Near Everglades City, FL 17 h into the forecast | ||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 26.68 | 81.83 | 15.5 | 87.6 | Fort Myers, FL
| AVAL | No landfall forecast
| %IMP
|
| GFNO | 27.12 | 82.48 | 12.5 | 156.2 | Venice, FL
| GFAL | 27.08 | 82.43 | 11.5 | 148.9 | Venice, FL
| %IMP | -22% | 5%
| | |||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 21 September 1999 0000 UTC (Tropical Storm Harvey).
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 21 September 1999 0000 UTC. The best track is shown in black.
Figure 3. Ensemble perturbation variance at the nominal sampling time 21 September 1999 0000 UTC from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.
Figure 4. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 21 September 1999 0000 UTC. The green circles represent the dropwindsonde locations.
