The US National Weather Service "International Services and Communication Systems" (ISCS) activity is a collective group of message dissemination systems used to provide weather, water and climate information to segments of the World Meteorological Organization (WMO) International community as described in WMO document No. 386 - Manual on the Global Telecommunication System. The ISCS systems provide service to WMO Regional Association IV (RA-IV) and are managed by the US National Weather Service (NWS) Dissemination Systems Branch (W/OPS17); they include:
ISCS systems are an integral part of the RA-IV Regional Meteorological Telecommunications Network (RMTN), which focuses on the timely collection and delivery of both time-critical and routine watches, warnings, observations and forecasts.
Additional telecommunication systems are identified as part of the RA-IV RMTN which supplement the capabilities of the ISCS systems for the exchange of messages. These other systems include: