The National Tsunami Warning Center (NTWC) serves the continental United States, Alaska, Puerto Rico, the Virgin Islands and Canada. The Pacific Tsunami Warning Center (PTWC) directly serves the Hawaiian Islands and the U.S. Pacific territories and is the primary international forecast center for the Pacific Tsunami Warning and Mitigation System and the Tsunami and Other Coastal Hazards Warning System for the Caribbean and Adjacent Regions.
Methods to obtain these messages are provided below.
NTWC has a feed available at http://ntwc.arh.noaa.gov/events/xml/PAAQAtom.xml that can be monitored for product updates.
The NTWC Twitter feed and/or the PTWC Twitter feed can be used to receive text messages. In the U.S. you can send a text message to 40404 with 'follow NWS_NTWC' for NTWC messages, and 'follow NWS_PTWC' for PTWC messages. To stop receiving NTWC text messages, you can text 'stop NWS_NTWC' to 40404.
For more details on Twitter and SMS, please click the Twitter SMS help page
NOTE: Not all countries/carriers use 40404 - please refer to the Twitter short or long code page.
The UNESCO/IOC service will provide NTWC bulletins for seismic events greater than magnitude 6.5 . Other tsunami warning centers provide information to this list also
NTWC generates Common Alerting Protocol (CAP) documents for events. The CAP document is available at:
The CAP tsunami profile (CAP-TSU), is documented at: http://ntwc.arh.noaa.gov/?page=cap
National Weather Service Systems
Other Federal Systems