Forecast Korea draws the open weather models that cover the Korean peninsula whole on one map and one time axis, so the forecasts can be read against each other: the Japan Meteorological Agency's 5 km mesoscale model (MSM), its global model (GSM) on a 10 km regional window and globally, its coastal and global wave models, and ECMWF's deterministic run. Times are Korea Standard Time; temperatures Celsius, winds metres per second, as KMA gives them. Free, no account, no key.

It renders nothing of its own. Every frame is Forecast Japan's — palettised PNGs in one catalog contract, proxied same-origin by this site — because the domains Forecast Japan already renders take in the peninsula from Jeju to the Tumen. Rule for this site, as for Forecast Ukraine and Forecast Russia: re-purpose the network's output, never start a second ingest of the same data.

The Korea Meteorological Administration runs KIM (its own global model), and the UM-based regional and local models RDAPS and LDAPS. Their output is offered through KMA's API Hub and the open data portal, to registered users with an issued key and a daily request quota, largely as point and text products — not as open GRIB files a third party may fetch on a schedule and redistribute as maps. A site like this one needs the latter.

If KMA's grids become openly redistributable, they go first: a national model on its own country is always the right default, as MSM is on Forecast Japan and ICON-D2 on Forecast Germany.

MSM, the regional GSM and ECMWF HRES are drawn on one frame (122–148°E, 23.5–46.5°N), the coastal waves on a degree wider; the global GSM and global waves on the western North Pacific (100–180°E, 0–60°N), which is where the typhoon frame opens. Switching model holds the valid time, never the forecast hour.

The hero is drawn in the projection KMA draws in: a Lambert conformal conic with standard parallels at 30°N and 60°N, origin 38°N 126°E, on KMA's sphere of radius 6,371.00877 km — the projection of KMA's 5 km digital-forecast grid and its synoptic charts. The relief is the Forecast Network atlas maker's plate (ETOPO 2022 with multidirectional and texture shading and a cross-blended tint), cut natively in that grid, and the MSM frame for the present hour is reprojected over it as it draws.

Borders and provinces are Natural Earth's. Both Koreas' provinces and metropolitan cities are drawn and are click targets, because the weather does not stop at the Military Demarcation Line and neither do the models. The East Sea is named as Koreans name it, with the Sea of Japan beside it in the explorer.

Every frame is a palettised PNG whose palette is the colour ramp, so the image is a reversible encoding of the forecast. The readout under the pointer and the value printed beside every city are read back out of the frame on screen, good to one step of the colour table — not from a separate file, because the value files Forecast Japan publishes are indexed against its own list of Japanese cities.

The default colour tables are JMA's ladder — its published legends for rain and wind, the same ladder on chosen breaks elsewhere (Forecast Japan's about page says which is which). Every other table in the network's collection is one click away in the explorer.

JMA: MSM, GSM and wave model GPV from the Japan Meteorological Agency, mirrored and published by the Research Institute for Sustainable Humanosphere, Kyoto University, whose archive makes this possible. ECMWF: contains modified Copernicus/ECMWF open data, © European Centre for Medium-Range Weather Forecasts, CC BY 4.0. Relief: ETOPO 2022, NOAA NCEI. Borders, provinces, rivers and places: Natural Earth. Basemap: © OpenStreetMap contributors.

Not an official warning service. For warnings, advisories and the official forecast, see the Korea Meteorological Administration (기상청).