Effects of Synoptic Surveillance on model forecasts for
10 August 2004 1800 UTC
Bonnie.


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 52
AVNO 42
%IMP19%
GFNO 22 15 35140268468
GFDL 22 67139200300437
%IMP 0% -337% -297%-43%-12% 7%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-27
AVNO-25
%IMP 7%
GFNO 14 6 21 21 15 20
GFDL -8-14 13 16 11 14
%IMP 43%-133% 38% 24% 27%30%

Landfall forecasts

12/1400 UTC 29.6N 85.1W St. Vincent/St. George Is., FL 44.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNNNo landfall forecast
AVNO29.3789.2932.0406.0Pilottown, LA
%IMP
GFNO30.2985.8045.0102.1Panama City Beach, FL
GFDL30.3786.2242.5137.6Blue Mountain Beach, FL
%IMP-50% -35%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 10 August 2004 1800 UTC (Tropical Storm Bonnie).

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 10 August 2004 1800 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 10 August 2004 1800 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 10 August 2004 1800 UTC.