Effects of Synoptic Surveillance on model forecasts for
17 September 2003 0000 UTC
Isabel.
Quicktime movie of GFS 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 | 33 | 58 | 39 | 90 | 256 | 491
| AVNO | 44 | 58 | 43 | 84 | 215 | 407
| %IMP | -33% | 0% | -10% | 7% | 16% | 17%
|
| GFNO | 31 | 22 | 29 | 49 | 192 | 531
| GFDL | 29 | 58 | 72 | 95 | 153 | 468
| %IMP | 6% | -164% | -148% | -94% | 20% | 12%
| INTENSITY (kt)
| MODEL | 12 h | 24 h | 36 h | 48 h | 60 h | 72 h | 84 h | 96 h | 108 h | 120 h
|
| AVNN | -39 | -38 | -36 | -16 | -1 | -8
| AVNO | -13 | -10 | -16 | -3 | -2 | -3
| %IMP | 67% | 76% | 56% | 81% | -100% | 63%
|
| GFNO | 3 | 11 | 3 | 5 | 23 | 29
| GFDL | 6 | 16 | 2 | 10 | 19 | 28
| %IMP | -100% | -45% | 33% | -100% | 17% | 3%
|
| SHNO | 2 | 3 | 1 | 18 | 39 | 39
| SHIP | 2 | 0 | -4 | 12 | 32 | 32
| %IMP | 0% | 100% | -300% | 33% | 18% | 18%
|
| DSNO | 2 | 3 | 1 | -9 | 1 | 5
| DSHP | 2 | 0 | -4 | -16 | -1 | 4
| %IMP | 0% | 100% | -300% | -78% | 0% | 20%
| | ||||||||||
| 18/1700 UTC 34.9N 76.2W Drum Inlet, NC 41.0 h into the forecast | |||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 35.02 | 76.13 | 42.5 | 14.8 | Ocracoke, NC
| AVNO | 35.09 | 75.98 | 42.5 | 29.1 | Ocracoke, NC
| %IMP | 0% | -197
|
| GFNO | 34.93 | 76.52 | 41.0 | 29.3 | Cape Lookout, NC
| GFDL | 34.72 | 76.46 | 39.0 | 31.0 | Cape Lookout, NC
| %IMP | und% | -6%
| | ||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 17 September 2003 0000 UTC (Hurricane Isabel).
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 17 September 2003 0000 UTC.
Figure 3. Ensemble perturbation variance at the nominal sampling time 17 September 2003 0000 UTC from the previous day NCEP ensemble forecast. The 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 17 September 2003 0000 UTC. The circles represent the dropwindsonde locations.
