Part of the mission of the National Weather Service (NWS) Tropical Prediction Center (TPC) is to save lives and protect property by issuing watches, warnings, forecasts, and analyses of hazardous weather conditions in the tropics. This section provides information about the roles of those responsible for providing hurricane information to emergency managers and decision makers.
The TPC is comprised of the National Hurricane Center (NHC), the Tropical Analysis and Forecast Branch (TAFB), and the Technical Support Branch (TSB). During hurricane season, the latter two provide support to the NHC.
The local NWS Weather Forecast Offices (WFOs) in hurricane-prone areas are also important participants in the forecast process.
The NHC and your local WFO have various roles in the forecast process that are closely coordinated. Their activities are summarized below.
Watch versus Warning - Know the Difference
A Hurricane Watch indicates the possibility that you could experience hurricane conditions within 36 hours. When a watch is issued, people should begin to put into practice their family's disaster plan and protective measures should be initiated, especially those actions that require extra time such as securing a boat, leaving a barrier island, etc.
A Hurricane Warning indicates that sustained winds of at least 74 mph are expected within 24 hours or less. Once this warning has been issued, people should be in the process of completing protective actions and deciding the safest location to be during the storm.
Observation
Observations including satellites, buoys, reconnaissance aircraft, and radar are the basis for all forecast and warning products issued by the NHC. Quality, quantity, and timeliness of remote sensing observations are critical for accurate and timely forecasts and warnings. www.nhc.noaa.gov/HAW2/english/forecast/observations.shtml
Analysis
The various observations are checked for quality, analyzed, and put into a suite of computer models.
The computer models take in the observations and perform millions of calculations to generate predictions of hurricane behavior and the general conditions of the atmosphere in which the hurricane is embedded. The model results are packaged as guidance for the appropriate national centers and local offices and for evaluation and use in the NWS's forecast and warning process.
Forecasts and warnings are coordinated between the national centers and local forecast offices to provide consistency, which is critical during severe weather episodes.
Once the coordination and collaboration process reaches group consensus, the issuing offices generate forecast and warning products for release to the public.
