Even after these two storms passed, the heat content in the Loop Current was well above the threshold needed to sustain a storm. This is vitally important to know for intensity change in storms approaching landfall. The ocean is not the only factor in hurricane intensity change. NOAA hurricane researchers also consider environmental data gathered around the storm by NOAA's Gulfstream-IV jet , a surveillance aircraft operated by NOAA's Aircraft Operations Center . Though the G-IV missions are designed to improved track forecasts for landfalling hurricanes, an added benefit is measurement of the wind shear and environmental moisture and stability that can affect intensity.
Wind shear is the difference in wind velocity at upper and low levels in the atmosphere.
High wind shear, dry air, and low stability are associated with weakening of tropical storms. Direct measurements of these variables is unavailable over the Gulf of Mexico without use of the Gulfstream jet. The data gathered suggest that much like major hurricanes Opal and Bret, the ocean represents a fuel-injector to the atmosphere for all types of tropical cyclones, even tropical storms and minimal hurricanes. Black and Shay hope that data gathered during this study will enhance knowledge and predictability of major hurricanes, which translates into improved intensity forecast, increased warning time and better preparedness in coastal regions. NOAA's mission is to describe and predict changes in the Earth's environment and to observe and wisely manage the nation's coastal and marine resources.