Effects of Synoptic Surveillance on model forecasts for
13 September 2004 1800 UTC
Ivan.
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 | 35 | 63 | 45 | 59 | 145 | 166 | 248 | 415 | 648 | 902
| AVNO | 63 | 75 | 78 | 118 | 179 | 163 | 257 | 390 | 595 | 803
| %IMP | -80% | -19% | -73% | -100% | -23% | 2% | -4% | 6% | 8% | 11%
|
| GFNO | 23 | 90 | 83 | 63 | 106 | 147 | 295 | 531 | 757 | 962
| GFDL | 41 | 93 | 122 | 117 | 175 | 196 | 350 | 564 | 823 | 973
| %IMP | -78% | -3% | -47% | -86% | -65% | -33% | -17% | -6% | -9% | -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 | -63 | -39 | -41 | -29 | -21 | 12 | 7 | 0 | 6 | -5
| AVNO | -66 | -40 | -38 | -37 | -27 | 6 | -1 | -2 | 4 | -2
| %IMP | -5% | -3% | 7% | -26% | -29% | 50% | 86% | und% | 33% | 60%
|
| GFNO | -25 | 1 | -8 | -10 | -2 | 38 | 29 | 23 | 20 | 10
| GFDL | -24 | 0 | -9 | -6 | -3 | 39 | 32 | 28 | 18 | 9
| %IMP | 4% | 100% | -13% | 40% | -50% | -3 | -10% | -22% | 10% | 10%
|
| | ||||||||||
| 14/0100 UTC 21.7N 85.2W 15 n mi SW of Cabo San Antonio, Cuba 7.0 h into the forecast | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 21.81 | 85.06 | 5.5 | 18.9 | Near La Fe, Pinar del Rio, Cuba
| AVNO | 21.40 | 85.34 | 4.5 | 36.3 | Near La Fe, Pinar del Rio, Cuba
| %IMP | -67% | -92%
|
| GFNO | 21.61 | 85.34 | 7.5 | 17.6 | Near La Fe, Pinar del Rio, Cuba
| GFDL | 21.55 | 85.31 | 5.5 | 20.2 | Near La Fe, Pinar del Rio, Cuba
| %IMP | -200% | -15%
|
|
16/0650 UTC 30.2N 87.9W Near Pine Beach, AL 61.0 h into the forecast
| MODEL | LAT | LON | TIME | ERROR | LOCATION
|
| AVNN | 30.33 | 87.58 | 68.0 | 33.9 | Gulf Shores, AL
| AVNO | 30.37 | 88.62 | 67.0 | 71.6 | Pascagoula, MS
| %IMP | 14% | -111%
|
| GFNO | 30.23 | 88.09 | 65.0 | 18.5 | Dauphin Island, AL
| GFDL | 29.05 | 89.14 | 59.0 | 175.1 | South Pass, LA
| %IMP | 50% | -846%
| | |||||||||||||
Figure 1. NCEP 850 - 200 hPa mean wind analysis for 13 September 2004 1800 UTC (Hurricane Ivan).
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 2004 1800 UTC.
Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 13 September 2004 1800 UTC.
