National Tsunami Warning Centres A National Tsunami Warning Centre is an agency officially designated by the ICG Member State government to monitor, coordinate and issue tsunami warnings and other related statements within their country according to established National Standard Operating Procedures. National Tsunami Warning Centres (NTWCs) have been established in 9 countries within the ICG/CARIBE EWS - Colombia, Costa Rica, Dominican Republic, Haiti, Mexico, Nicaragua, Panama, United States (National Tsunami Warning Center, NTWC) and Venezuela (Bolivarian Republic of).