The NWS's NHC maintains a continuous watch on tropical cyclones over the Atlantic, Caribbean, Gulf of Mexico, and Eastern Pacific from 15 May through 30 November. To produce a forecast, the NHC uses data from satellites, radars, and reconnaissance aircraft to establish the location of the storm's eye and to estimate the storm's intensity based on the pressure and wind speed. NHC forecasters use computer model results to predict future track and intensity and potential hazards such as storm surge, rainfall, and tornado activity. They issue advisories, discussions, probabilities, watches, and warnings for tropical storm-force winds and hurricane-strength winds. All this information provides the large scale picture which the local WFO then tailors to their specific areas (described in the local section).

The NHC selects warning areas based on the probability that a hurricane will make landfall within a given area. Because most storm damage occurs within a 125-mile swath (75 miles on the right-front quadrant, 50 miles on the left), forecasters select a warning area about 300 miles long to ensure that the potentially threatened population is warned. This warning area is larger than the expected damage path because forecasters must take into account possible changes in the track and intensity, as well as the average errors in hurricane track forecasts. These errors are discussed in more detail in the Uncertainty section. After the forecast products have been delivered, the NHC coordinates with other federal agencies such as FEMA, threatened states, local offices, and international customers. This coordination effort is critical in assuring that all of the key agencies have the information they need, will provide consistent information to the public and local decision makers, and will conduct their individual activities in concert with other efforts as efficiently as possible. During the "off-season," the NHC provides training for U.S. emergency managers and representatives from other countries affected by tropical cyclones and is involved in public awareness programs. NHC staff also conduct research to evaluate and improve hurricane forecasting techniques.