I just checked the latest run of the GFDL against the current Advisory.
GFDL Forecast:
FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

00 28.3 95.1 355./ 5.0
06 28.6 95.2 342./ 3.1
12 29.2 95.3 352./ 6.0
18 30.0 94.8 030./ 9.1

Current Advisory:
29.0N/ 94.6W ...BASED ON RADAR FIXES THE CURRENT MOTION...030/05

AT 1000 PM CDT...0300Z...THE CENTER OF TROPICAL STORM HUMBERTO WAS
LOCATED NEAR LATITUDE 29.0 NORTH...LONGITUDE 94.6 WEST OR ABOUT 25
MILES... 40 KM...SOUTH-SOUTHEAST OF GALVESTON TEXAS AND ABOUT 45
MILES... 70 KM...SOUTH-SOUTHWEST OF HIGH ISLAND TEXAS.

Humberto at 10PM CDT was 0.2 degree east of the 18 hour forecast position and 0.2 degree south of the 12 hour position.