Effects of Synoptic Surveillance on model forecasts for
13 September 2002 0000 UTC
HANNA.
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 | 52. | 82. | 147. | 317. | 580. |
| AVNO | 138. | 192. | 254. | 380. | 604. |
| %IMP | -165% | -134% | -173% | -20% | -4%
|
| GFNO | 23. | 145. | 147. | 372. | 710.
| GFAL | 49. | 56. | 78. | 187. | 439.
| %IMP | -113% | 61% | 47% | 50% | 38%
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -20. | -21. | -19. | -6. | -6. |
| AVNO | -16. | -16. | -23. | -4. | -4. |
| %IMP | 20% | 24% | -68% | 33% | 33%
|
| GFNO | -12. | -14. | -9. | 32. | 18.
| GFDL | -14. | -15. | -9. | 25. | 30.
| %IMP | -17% | -7% | 0% | 22% | -66%
|
| SHNO | -11. | -12. | -7. | 27. | 32.
| SHIP | -11. | -11. | -5. | 28. | 31.
| %IMP | 0% | 8% | 29% | -4% | 3%
|
| DSNO | -11. | -12. | -16. | 9. | 7.
| DSHP | -11. | -11. | -15. | 9. | 8.
| %IMP | 0% | 8% | 6% | 0% | -14%
| | ||||||||||
| 14/0800 UTC 29.1N 89.1W Mouth of the Mississippi River 32 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 29.06 | 88.37 | 27.5 | 71.0 | Near Pilottown, LA
| AVAL | 30.53 | 87.11 | 32.0 | 249.1 | Pensacola, FL
| %IMP | 100% | -251%
|
| GFNO
| GFAL | 28.99 | 89.17 | 27.0 | 14.0 | South Pass, LA
| %IMP
|
|
14/1500 UTC 30.4N 88.4W Alabama/Mississippi border 39 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 30.29 | 88.08 | 33.0 | 33.0 | Dauphin Island, AL
| AVAL | 30.53 | 87.11 | 32.0 | 124.4 | Pensacola, FL
| %IMP | -17% | -277%
|
| GFNO
| GFAL | 30.42 | 88.98 | 34.5 | 55.6 | Biloxi, MS
| %IMP
| | |||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 13 September 2002 0000 UTC (Tropical Storm Hanna).
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 13 September 2002 0000 UTC. The best track is shown in black.
Figure 3. Ensemble perturbation variance at the nominal sampling time 13 September 2002 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 13 September 2002 0000 UTC. The green circles represent the dropwindsonde locations.
