Dropwindsonde observations from research aircraft have been shown to produce significant improvements in the primary numerical guidance for the Tropical Prediction Center (TPC) official track forecasts. The size of the improvements (16% - 30% for 12 - 60 h forecasts) were as large as those obtained over the previous 20 - 25 years. As a result, in 1996, NOAA procured a Gulfstream-IV jet aircraft (G-IV) to conduct operational "Synoptic Surveillance" missions in the environments of hurricanes threatening the coastline of the continental United States, Puerto Rico, and the Virgin Islands, and a new dropwindsonde, based on the Global Positioning System (GPS), has been developed by the National Center for Atmospheric Research (NCAR). The first year of operational missions (1997) has shown similar improvements in track forecasts, and, for the first time, substantial improvements in intensity forecasts. However, not all forecasts are improved. Research into targeting and sampling strategies in these cases has shown that regions which most impact the forecasts can be found before the G-IV flights so that theycan be sampled by dropwindsondes, and, further, that proper sampling methods of these target regions must be developed to obtain the largest model impacts