Meeting 2026 03 12 - wmo-im/tt-wismd GitHub Wiki
Date/Time
Thursday 12 March 2026 13h - 14h UTC
Location
MS Teams
Attendees
Team
| Name | Affiliation/Country | GitHub handle | Attendance |
|---|---|---|---|
| Tom KRALIDIS (Chair) | Canada | @tomkralidis | X |
| Guillaume AUBERT | EUMETSAT | @gaubert | |
| Takumu EGAWA (observing member) | Japan | ||
| Lara FERRIGHI | Norway | @ferrighi | |
| Sylvain GRELLET | France | @sgrellet | |
| Xinqiang HAN | China | @Amienshxq | |
| Vera KORBULAKOVA | Russian Federation | @VeraKorbulakova | |
| Ian MCDONALD | EUMETSAT | @McDonald-Ian | |
| Steve OLSON | USA | @solson-nws | |
| Ján OSUSKY | HMEI | @josusky | X |
| David PODEUR | France | @davidpodeur | |
| Julia SIELAND | Germany | @jsieland | |
| Yutaro TONOOKA | Japan | YutaroJMA | |
| Anna MILAN | WMO Secretariat | @amilan17 | X |
Agenda
-
Previous meeting minutes and actions (all)
-
Secretariat updates (Anna)
- Review process for publishing experimental (state) topics to codes.wmo.int
-
WTH
-
WNM
- None planned
-
WME
- None planned
Notes (DRAFT)
Tome opened the meeting with a welcome and noted that it was not necessary to review previous tasks and the WNM and WME specifications are fairly stable for the momeent.
Experimental Topic Status & Codes Registry Workflow
The central discussion was a newly introduced workflow change where WIS2 topics can now be published to the WMO codes registry with an "experimental" status before receiving final formal approval. Historically, topics were only published after full approval. The shift was driven by a desire to unblock data providers who are ready to share data on WIS2 now but may have to wait months for formal approval. Anna confirmed this new approach hadn't yet been formally documented and that needed to be addressed.
Risks of the Experimental Status The group identified several concerns with the new approach:
- Downstream systems (like WIS2 boxes, GDC validation, metadata catalogs) do not check or propagate the "experimental" status — they treat experimental topics as fully operational, which creates a gap.
- Users publishing metadata records or subscribing to topics are not warned that a topic is experimental and may change or be retracted.
- There's a risk that data providers using experimental topics will never migrate to approved topics ("experimental forever"), especially those working with rigid contractor specifications.
Proposed Solutions
Use the existing experimental topic branch in the hierarchy: Rather than changing the status field in codes.WMO, new proposed topic subtrees should be physically placed under the existing experimental branch in the topic hierarchy. Once formally approved, they'd be moved to their final location. This was seen as cleaner and already supported by current infrastructure. Lifecycle governance: The group agreed that experimental topics need a time limit (proposed ~6 months), after which they either get approved and moved to an operational branch, or are removed. This would be documented in a WIS2 "cookbook" recipe. Monitoring: Steve raised whether the global monitor should track experimental topic usage to flag long-running experimental publications. Documentation: Tom committed to opening a GitHub issue to track the workflow change and circulate it to the broader team (including colleagues Hassan, Enrico, and Remi). The topic will also be raised at the next W2IT meeting.
Publication Script Automation
The current automation already pushes centre-ids and space-based-observations (satellites) to the codes registry immediately when merged to the main branch. The group discussed updating publication scripts to route experimental topics into the experimental folder of codes.WMO and to migrate them when they become operational.
Vertical Profilers topic
The team reviewed Add topic/s for vertical profiles #271 and there were no objections raised to the topic.
Weather radar topic
The team reviewed Add topic/s for weather radar #273
Steve raised a side point that radar data currently appears under "weather surface-based observations," which could be considered a misnomer since radar scans at multiple elevation angles. Anna and Ján clarified that the WMO definition of "surface-based" simply means not in space (i.e., satellite), so radar, radiosondes, and even aircraft fall under that category. The team proposes the following sub-topics instead of weather_radar
- weather/surface-based-observations/radar/volumetric
- weather/surface-based-observations/radar/composite
- weather/surface-based-observations/radar/radob
High resolution land surface observation
The team reviewed Add topic/s for high temporal and spatial resolution observations from land surface stations #274 Ján mentioned an open question about how to handle observation frequency within the topic hierarchy for synoptic data — whether to use a simple binary (standard vs. high-resolution) or a more granular set of categories.
Actions
- Tom: Open a GitHub issue on the experimental topic lifecycle/workflow and notify W2IT DONE https://github.com/wmo-im/wis2-topic-hierarchy/issues/286
- Tom/Anna: Document the new experimental publishing workflow (when determined).
- tt-wismd: Review and comment on open GitHub issues before the next meeting.
- Tom & Anna: Schedule the next meeting (~1 month out).