Switzerland coverage is live at 4 km

Switzerland is live. As of this morning, the Convek API serves 4 km soaring forecasts across the entire Swiss Alps. Interlaken, Verbier, Grindelwald, Fiesch, Niederhorn, Mythen, Engelberg, Crans-Montana, Lauterbrunnen, and every coordinate in between - one API call, every field as JSON, four cycles a day.

This is the first European country in the expansion batch, and Switzerland was an obvious place to start. It has the densest soaring population per square kilometre in Europe, an absurdly varied terrain mix from lake-edge sites to the Bernese 4000ers, and a meteorology that punishes any model coarser than about 5 km. Thermals trigger on south-facing rock faces hours before they fire on the valley floor. Cloudbase climbs through 4000 m on the best days, then collapses 800 m in twenty minutes when the föhn breaks. The wind picture switches between valley-driven and synoptic flow through the afternoon. None of that resolves at 13 km. Most of it does at 4 km.

Every field that exists for the UK exists for Switzerland today: thermal strength (`wstar_ms`), the glider-capped ceiling (`hglider_agl_m`, which over the Bernese Oberland on a strong summer day reads well above 3000 m AGL), cloudbase in both feet AGL and metres MSL, trigger temperature, surface and 925 hPa winds, day rating, full forecast soundings, and route corridor sampling. The MSL cloudbase reading is the one Alpine pilots end up using most - launch altitudes vary by 2000 m between Swiss sites, so the AGL number on its own can be misleading when planning a transition.

The runs themselves are fast. End-to-end the Switzerland cycle takes about 13 minutes of compute on the worker, which means the 06z forecast - the one most pilots check at breakfast - is published well before midday local time. Four cycles a day at 00z, 06z, 12z and 18z UTC, 49 hour horizon, hourly resolution.

The rectangle runs 5.2 E to 11.2 E and 45.3 N to 48.3 N, with a deliberate buffer into France, Italy, Germany and Austria. That buffer is not coverage. The outer cells of any WRF run are dominated by GFS boundary forcing rather than regional physics, and any soaring area sitting in that contaminated rim forecasts badly. Pushing the rim outside Switzerland keeps the country itself in the clean interior of the model. The day-window calculations and sounding labels use `Europe/Zurich`, which sounds trivial but is the kind of thing that is irritating to discover wrong on a Saturday morning.

None of this required new code. The pipeline is the same WRF-ARW + GFS + YSU/WSM3/Noah/RRTM stack that has been running the UK service for months. Switzerland is configuration: a different rectangle, a different timezone, its own Better Stack heartbeat so a UK failure cannot mask a Swiss one. That was the point of the multi-country work that landed last month, and Switzerland is the first proof that the work was worth doing.

Slovenia is next, scheduled for next week. Austria and Czechia follow weekly through the rest of May. Every country runs through the same launch gate: a benchmark cycle, a manual sanity check against known sites, eight clean scheduled cycles in a row, then the announcement. Switzerland has cleared that gate. The rest are queued.

To try it: free tier is 25 queries a day, no card required. Pass `region=ch` and a `lat` / `lon` inside the box to `/v1/site` and you are done. Full coordinate box and field list on the Switzerland coverage page, and live API reference at the API docs.

If you fly the Swiss Alps, run a school there, or are building anything that needs a proper Alpine forecast feed instead of a screenshot of someone else's map, this is the one to plug in. Have a play and tell me what breaks.