Japan · Numerical weather prediction
JMA GSM model
The Japanese model. Coarse globally in open data but a valuable independent member, especially for the West Pacific. Also known as Japanese model, GSM, MSM.
Run by
Japan Meteorological Agency
Resolution
~55 km open data global; 5 km MSM over Japan
Updates · range
4 per day · up to 11 days
Where JMA is strong
Typhoon tracks and East Asian monsoon patterns; MSM detail over Japan.
Where to be careful
Coarse open-data grid misses local effects; no wind-gust output.
How to read the JMA forecast on MeteoStack
On every city page, JMA is one row of the stack: each cell is one hour, coloured by rain, temperature, wind or cloud. Compare its row against the consensus line at the top. If JMA is far from the others, treat its outlier signal with caution, or as an early warning if it is a model that is strong in that situation (see above).