Effects of Synoptic Surveillance on model forecasts for
15 August 2003 0600 UTC
Erika.


Quicktime movie of GFS 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
GFSN 78 46122
GFSO 80 44137
%IMP-3% 4%13%
GFNO 83141 83
GFDL 81134 87
%IMP 2% 5%-5%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
GFSN-23-33-19
GFSO-23-32-18
%IMP 0% 3% 5%
GFNO -4-17 0
GFDL 0-14 5
%IMP100%18%und%
SHNO -1 -1 33
SHIP 0 0 35
%IMP100%100%-6%
DSNO -1 -1 11
DSHP 0 0 8
%IMP100%100%27%

Landfall forecasts

16/1030 UTC 25.3N 97.4W Boca San Rafael, Mexico 28.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
GFSN25.8497.1828.5 29.8Guajardo, Tamaulipas, Mexico
GFSO25.8697.1629.0 66.7Isla las Vaquitas, Tamaulipas, Mexico
%IMPund%-124%
GFNO26.0697.2130.586.6Guajardo, Tamaulipas, Mexico
GFDL26.0297.1630.539.4Isla la Tuna, Tamaulipas, Mexico
%IMP100% 54%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 15 August 2003 0600 UTC (Tropical Storm Erika).

Figure 2. Track forecasts for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the GFS and GFDL models initialized on 15 August 2003 0600 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 15 August 2003 0600 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 15 August 2003 0600 UTC.