Effects of Synoptic Surveillance on model forecasts for
15 July 2003 0000 UTC
Claudette.


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
GFSN126169184280314
GFSO 67147188324322
%IMP47%13%-2%-16%-3%
GFNO 49 74101165167
GFDL 45 82 92188247
%IMP 8% 11% 9%-14%-48%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
GFSN-48-27-16-14-14
GFSO-44-22-13-12 -8
%IMP 8%19%19%14%43%
GFNO -2 29 7 21 8
GFDL -5 27 8 18 13
%IMP-150% 7%-14%14%-63%
SHNO-20 8 25 32 39
SHIP -19 9 26 33 39
%IMP 5%-13%-4%-3% 0%
DSNO-20 -2 -2 -1 2
DSHP-19 -2 -1 -1 2
%IMP 5% 0%50% 0% 0%

Landfall forecasts

15/1530 UTC 28.3N 96.2W Matagorda Island, TX 15.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
GFSN27.2497.5225.5175.2Yarborough, TX
GFSO27.7297.3226.0127.4Corpus Christi, TX
%IMP -5% 27%
GFNO28.1097.1922.0 99.4Rockport, TX
GFDL28.1296.8426.0 65.8Rockport, TX
%IMP-62% 34%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 15 July 2003 0000 UTC (Tropical Storm Claudette).

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 July 2003 0000 UTC.

Figure 3. Ensemble perturbation variance at the nominal sampling time 15 July 2003 0000 UTC from the previous day NCEP ensemble forecast. The circles represent the dropwindsonde locations.

Figure 4. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 15 July 2003 0000 UTC. The circles represent the dropwindsonde locations.

Figure 5. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 15 July 2003 0000 UTC.