Guidance on transition from GTS/WIS1 to WIS2
This page refers to the WIS 2.0 Implementation plan and transition from GTS/WIS1 to WIS2.
For an overview of WIS 2.0, see: https://community.wmo.int/en/activity-areas/wis/WIS2-overview
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WIS 2.0 Implementation Plan | Transition Guide (WMO-No.1323) | Temporary Global Services | Guidance for RTH | Guidance for NC and DCPC | Guidance for GISC
WIS 2.0 implementation plan
The WMO Information System 2.0 (WIS 2.0) will be implemented according to the schedule provided in Figure 1. Migration to WIS2 is planned to occur between 2025 and 2030, with an expected progress rate of up to 90%. The GTS is planned to be decommissioned by 2033.
Figure 1 WIS 2.0 Implementation Timeline
Transition Guide (WMO-No.1323)
According to the WIS 2.0 implementation plan (see Figure 1), the Global Telecommunication System (GTS) is scheduled to be decommissioned by 2033. By that time, National Meteorological and Hydrological Services (NMHSs) are expected to have fully transitioned to the WIS 2.0 platform for data exchange.
To support a smooth and coordinated transition from WIS/GTS to WIS 2.0, dedicated transition guidance has been developed. This guidance outlines the core principles of the transition, provides a step-by-step roadmap for migration, and highlights key milestones, responsibilities, and timelines for implementation. It also recommends technical approaches, and strategies for minimizing the duration of parallel operations.
The transition guide aims to ensure that all Members are equipped with the necessary guidance and knowledge to migrate effectively while maintaining continuity of operations and data exchange throughout the process.
For more information, see the full WIS2 Transition Guide.
Temporary Global Services
During the 2025-2033 transition period, in order to avoid some WIS centres being forced to run both data-sharing frameworks (WIS2 and GTS) simultaneously, and given the challenges associated with maintaining two operational systems for the same purpose, two temporary Global Services will ensure data is available through both systems:
- GTS-to-WIS2 gateway: This service is implemented as a dedicated WIS2 node that re-publishes GTS bulletins on the WIS2 network, using the topic hierarchy: origin/a/wis2/{gateway-centre-id}/data/[core|recommended]/T1/T2/A1/A2/ii/CCCC
- WIS2-to-GTS gateway: This service is implemented by a Regional Transport Hub that subscribes to WIS2 and routes received data through their Message Switching System for distribution onto the GTS.
To ensure resilient operation, there will be more than one instance of each of the gateways.
Guidance for RTH
Regional Telecommunication Hubs (RTHs) shall keep their Message Switching Systems (MSS) operational and continue collecting bulletins from associated National Centres (NCs) and Data Collection or Production Centres (DCPCs) that have not yet migrated to WIS 2.0. These bulletins must be published and transmitted in the appropriate format via the Main Telecommunication Network, either directly or through the relevant World Meteorological Centre (WMC) or RTH, within the Global Telecommunication System (GTS).
This arrangement must remain in place until all Members within the RTH’s Area of Responsibility (AoR), including their associated NCs and DCPCs, have fully transitioned to WIS 2.0.
Once the RTH and all NCs and DCPCs in its AoR have completed the migration, the RTH may choose to decommission its MSS. In such cases, the RTH should contact the WMO Secretariat at wis@wmo.int to coordinate the deactivation of its MSS in a timely and orderly manner.
Guidance for NC and DCPC
National Centres (NCs) and Data Collection or Production Centres (DCPCs) shall operate one or more WIS 2.0 Nodes to publish their data and associated discovery metadata in WIS 2.0. It is strongly recommended that planning and preparation for migration begin well in advance, with the goal of completing the transition preferably by 2030, and no later than 2033. The migration of an NC or DCPC to WIS 2.0 can be considered complete once at least one WIS 2.0 Node is fully operational and all datasets previously transmitted via the GTS are also made available through WIS 2.0.
An NC or DCPC that has implemented a WIS 2.0 Node and is publishing all data previously transmitted via the GTS on WIS 2.0 may, if they choose, discontinue GTS-based data transmission. For NCs that operate a Message Switching System (MSS), this may include deactivating their MSS. In such cases, they must contact the WMO Secretariat at wis@wmo.int to coordinate the MSS deactivation in a timely and orderly manner.
For NCs that do not operate an MSS but instead send their data to the GTS via email, FTP, or other indirect methods through their associated RTH, the NC should inform both the RTH and the WMO Secretariat of their intention to stop GTS data submission, ensuring a coordinated transition to WIS 2.0.
An NC or DCPC shall keep WIS1 and GTS operational in parallel with the WIS2 systems until reception of a communication from the WMO Secretariat allowing the switch from the WIS1 and GTS systems.
When NCs/DCPCs decide to stop transmitting data on the GTS, they must include the relevant GTS properties in the WIS 2.0 Notification Message, as specified in the WIS 2.0 to GTS gateway technical requirements (see section 3.2.3 of the Transition Guide).
Guidance for GISC
Global Information System Centres (GISCs) shall support NCs and DCPCs in its area of responsibility in the migration and operation of WIS2. Information about the assigned GISC for each NC and DCPC can be found here: https://community.wmo.int/en/wis-centres
Each GISC shall maintain their WIS1 Catalogue and Cache as long as WIS users are using their services for operations. When a GISC has successfully migrated its users to WIS2, the GISC may stop its WIS1 Cache and Catalogue service and shall inform the WMO Secretariat at wis@wmo.int .
GISC Seoul and GISC Offenbach will continue to provide WIS1 discovery metadata and the WIS1 Catalogue until the transition from GTS and WIS1 to WIS2 is completed or deemed unnecessary when all WIS1 users have migrated to WIS2.
(Last update: 30 June 2025)