Effects of Synoptic Surveillance on model forecasts for
12 August 2004 1800 UTC
Charley.


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
AVNN102120231286328
AVNO 41 55164236267
%IMP60%54%29%17%19%
GFNO 56128265450635
GFDL 46 90244459656
%IMP18% 30% 8%-2%-3%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-75-87-44-21 -6
AVNO-66-75-36-19 -6
%IMP12%14%18%10% 0%
GFNO-15-16 11 25 15
GFDL -4-13 5 20 18
%IMP73%19%55%20%-20%

Landfall forecasts

13/0430 UTC 22.7N 82.6W Near Playa del Cajio, Cuba 10.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 22.5582.9114.0 35.9San Cristobal, Pinar del Rio, Cuba
AVNO22.5782.9010.0 34.0San Cristobal, Pinar del Rio, Cuba
%IMP 86% 5%
GFNO22.7082.7813.0 18.4Artemisa, La Habana, Cuba
GFDL22.7182.7312.5 13.3Las Canas, La Habana, Cuba
%IMP 20% 28%
13/1945 UTC 26.6N 82.2W Near Cayo Costa, FL 25.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 27.9383.1032.5172.4Clearwater Beach, FL
AVNO27.7082.6430.5129.7St. Petersburg, FL
%IMP 30% 25%
GFNO27.7782.7334.0140.1St. Petersburg, FL
GFDL27.5682.6132.5114.1Anna Maria Island, FL
%IMP 19% 19%
13/2045 UTC 26.9N 82.1W Near Punta Gorda, FL 26.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 29.1082.9036.0256.7Cedar Key, FL
AVNO27.7082.6430.5103.6St. Petersburg, FL
%IMP 59% 60%
GFNO28.4382.5736.5176.2Hernando Beach, FL
GFDL27.5682.6132.5 89.0Anna Maria Island, FL
%IMP 41% 49%
14/1400 UTC 33.0N 79.4W Near Cape Romain, SC 44.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN No landfall forecast
AVNONo landfall forecast
%IMP
GFNONo landfall forecast
GFDLNo landfall forecast
%IMP
14/1600 UTC 33.8N 78.7W Near North Myrtle Beach, SC 46.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN No landfall forecast
AVNONo landfall forecast
%IMP
GFNONo landfall forecast
GFDLNo landfall forecast
%IMP

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 12 August 2004 1800 UTC (Hurricane Charley).

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 12 August 2004 1800 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 12 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 12 August 2004 1800 UTC.