Pacific Ocean	Hawai`i	Indian Ocean	Caribbean Sea
Magnitude Message Type WMO AWIPS NWW tsunami Pacific Ocean-wide Tsunami Warning WEPA40 PHEB TSUPAC HFOTSUPAC Pacific Ocean-wide Tsunami Warning Supplement Pacific Ocean-wide Tsunami Warning Cancellation ≥7.9 Expanding Regional Tsunami Warning (sample) WEPA40 PHEB TSUPAC HFOTSUPAC Expanding Regional Tsunami Warning Supplement Expanding Regional Tsunami Warning Cancellation 7.6-7.8 Fixed Regional Tsunami Warning WEPA40 PHEB TSUPAC HFOTSUPAC Fixed Regional Tsunami Warning Supplement Fixed Regional Tsunami Warning Cancellation 6.5-7.5 Tsunami Information Bulletin (sample) WEPA42 PHEB TIBPAC HFOTIBPAC Tsunami Information Bulletin Supplement Colors correspond to the message severity (red=most, green=least). "WMO" = World Meteorological Organization message header (more information). "AWIPS" = Advanced Weather Interactive Processing System header (more information). "NWW" = NOAA Weather Wire header (more information). For more information, see NOAAPORT.

Message Definitions:

• Tsunami Warning
  The highest level of tsunami alert. Warnings are issued due to the imminent threat of a tsunami from a large undersea earthquake or following confirmation that a potentially destructive tsunami is underway. They may initially be based only on seismic information as a means of providing the earliest possible alert. Warnings advise that appropriate actions be taken in response to the tsunami threat. Such actions could include the evacuation of low-lying coastal areas and the movement of boats and ships out of harbors to deep water. Warnings are updated at least hourly or as conditions warrant to continue, expand, restrict, or end the warning.
  
  
• Tsunami Watch
  The second highest level of tsunami alert. Watches are issued by the TWCs based on seismic information without confirmation that a destructive tsunami is underway. It is issued as a means of providing an advance alert to areas that could be impacted by destructive tsunami waves. Watches are updated at least hourly to continue them, expand their coverage, upgrade them to a Warning, or end the alert. A Watch for a particular area may be included in the text of the message that disseminates a Warning for another area.
  
  
• Tsunami Advisory
  Advisories are issued due to the threat of a potential tsunami which may produce strong currents or waves dangerous to those in or near the water. Coastal regions historically prone to damage due to strong currents induced by tsunamis are at the greatest risk. The threat may continue for several hours after the arrival of the initial wave, but significant widespread inundation is not expected for areas under an advisory. Appropriate actions to be taken by local officials may include closing beaches, evacuating harbors and marinas, and the repositioning of ships to deep waters when there is time to safely do so. Advisories are normally updated to continue the advisory, expand/contract affected areas, upgrade to a warning, or cancel the advisory.
  
  
• Tsunami Information Bulletin/Statement
  A text product issued to inform that an earthquake has occurred and to advise regarding its potential to generate a tsunami. In most cases, a Tsunami Information Bulletin indicates there is no threat of a destructive tsunami, and are used to prevent unnecessary evacuations as the earthquake may have been felt in coastal areas. A Tsunami Information Bulletin may, in appropriate situations, caution about the possibility of a destructive local tsunami. A supplemental Tsunami Information Bulletin may be issued if important additional information is received such as a sea level reading showing a tsunami signal. A Tsunami Information Bulletin may also be upgraded to a watch or warning if appropriate.