ww3-mcp

MCP server for NOAA GFS-Wave (WAVEWATCH III) forecasts and NDBC buoy wave observations.

Requirements — ecCodes (native library)

The forecast tools read GFS-Wave GRIB2 via cfgrib, which needs the ecCodes C library — not pip-installable on every platform. If it's missing, the GRIB tools return a clear setup message (the NDBC buoy tools work without it). Install ecCodes one of:

• conda (easiest): conda install -c conda-forge eccodes cfgrib
• Debian/Ubuntu: apt-get install libeccodes0 then pip install cfgrib
• macOS (Homebrew): brew install eccodes then pip install cfgrib

Features

• GFS-Wave Forecasts — Wave height, period, direction from NOMADS GRIB2 data (up to 16 days)
• NDBC Buoy Observations — Realtime and historical wave measurements from ~1000+ buoys
• Model Validation — Compare GFS-Wave forecasts against buoy observations

Tools (9)

Discovery

Buoy Observations

Wave Forecasts

Installation

# Using uvx (recommended)
uvx ww3-mcp

# Or install with pip
pip install ww3-mcp

Configuration

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "ww3": {
      "command": "uvx",
      "args": ["ww3-mcp"]
    }
  }
}

Data Sources

• NOMADS Grib Filter — GFS-Wave GRIB2 data subsetted by variable and region
• AWS S3 (noaa-gfs-bdp-pds) — Cycle availability checks
• NDBC Realtime2 — ~45 days of buoy observations
• NDBC Active Stations — Station registry XML

All data sources are free, public NOAA APIs. No API keys required.

Development

cd servers/ww3-mcp
uv sync --group dev
uv run pytest tests/ --ignore=tests/test_live.py --ignore=tests/test_mcp_protocol.py -v

License

MIT