Effects of Synoptic Surveillance on model forecasts for
03 September 2004 0600 UTC
Frances.


Quicktime movie of AVN DLM wind model forecast
Quicktime movie of DLM wind data increment


TRACK AND INTENSITY PERFORMANCE

TRACK (km)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN 37 15 32 60104140 83115285365
AVNO 54 67 15 70 90117 73101205319
%IMP-46%-347% 53%-17%13%16%12%12%28%13%
GFNO 51 10 41 95162183182272544 728
GFDL 51 23 41 92147178125173372 530
%IMP 0% -130% 0% 3% 9% 3%31%36%32%27%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-47-37-25-28 -2 -5 -2 -7 -4 -1
AVNO-14 -8 -8-14 4 -6 -2 -5 -6 -2
%IMP70%79%68%50%-100%-20% 0%29%-50%-100%
GFNO 3 11 10 5 27 23 25 13 12 35
GFDL 3 18 21 12 28 22 23 14 15 26
%IMP 0%-64%-110%-140%-4% 4% 8%-7%-25%26%

Landfall forecasts

03/1000 UTC 25.1N 76.1W Eleuthera Island, Bahamas 4.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN25.1776.01 2.5 11.9Eleuthera Island, Bahamas
AVNO25.1776.08 4.0 8.0Eleuthera Island, Bahamas
%IMP 100% 33%
GFNO25.2076.21 6.5 15.7Eleuthera Island, Bahamas
GFDL25.0476.13 5.0 7.3Eleuthera Island, Bahamas
%IMP 60% 54%
04/1000 UTC 26.6N 78.2W Grand Bahama Island, Bahamas 28.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN26.6078.36 29.0 15.9Grand Bahama Island, Bahamas
AVNO26.9277.82 22.0 51.8Abaco Island, Bahamas
%IMP-500%-126%
GFNO26.6378.13 28.0 7.8Grand Bahama Island, Bahamas
GFDL26.7278.05 28.0 20.0Grand Bahama Island, Bahamas
%IMP 0%-156%
05/0430 UTC 27.2N 80.2W South end of Hutchinson Island, FL 46.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN28.1680.63 57.0114.7Melbourne, FL
AVNO27.9180.46 56.5 82.9Palm Bay, FL
%IMP 5% 28%
GFNO29.0680.91 63.5218.0Port Orange, FL
GFDL28.7880.71 61.5182.5Titusville, FL
%IMP 11% 16%
06/1800 UTC 30.1N 84.0W Mouth of Aucilla River, FL 84.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNNNo landfall forecast
AVNONo landfall forecast
%IMP
GFNONo landfall forecast
GFDLNo landfall forecast
%IMP

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 03 September 2004 0600 UTC (Hurricane Frances).

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 03 September 2004 0600 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 03 September 2004 0600 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 03 September 2004 0600 UTC.