Effects of Synoptic Surveillance on model forecasts for
Hurricane Isabel.

Quicktime movie of DLM wind analyses
Quicktime movie of DLM wind data initial increments

Assessments for each forecast time at

September 13, 2003				18 Z
September 14, 2003	00 Z	06 Z	12 Z	18 Z
September 15, 2003	00 Z	06 Z	12 Z	18 Z
September 16, 2003	00 Z	06 Z	12 Z	18 Z
September 17, 2003	00 Z	06 Z	12 Z	18 Z
September 18, 2003	00 Z	06 Z	12 Z

Figure 1a. Track forecast errors for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the GFS and GFDL models for the Hurricane Isabel synoptic surveillance missions.

Figure 1b. Track forecast improvements for the GFS and GFDL models for the the Hurricane Isabel synoptic surveillance mission.

Figure 2. Forecast errors for the landfall of Hurricane Isabel at Drum Inlet, NC, in the (a) cross- and (b) along-track directions for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the GFS and GFDL models.