@cyanheads/nws-weather-mcp-server

v0.6.1 pre-1.0

Get US weather forecasts, active alerts, and current observations via the National Weather Service API. STDIO or Streamable HTTP.

public 7 tools 1 resources protocol 2025-11-25 github cyanheads/nws-weather-mcp-server

claude mcp add --transport http nws-weather-mcp-server https://nws.caseyjhand.com/mcp

codex mcp add nws-weather-mcp-server --url https://nws.caseyjhand.com/mcp

{
  "mcpServers": {
    "nws-weather-mcp-server": {
      "url": "https://nws.caseyjhand.com/mcp"
    }
  }
}

gemini mcp add --transport http nws-weather-mcp-server https://nws.caseyjhand.com/mcp

{
  "mcpServers": {
    "nws-weather-mcp-server": {
      "command": "bunx",
      "args": [
        "@cyanheads/nws-weather-mcp-server@latest"
      ]
    }
  }
}

{
  "mcpServers": {
    "nws-weather-mcp-server": {
      "type": "http",
      "url": "https://nws.caseyjhand.com/mcp"
    }
  }
}

curl -X POST https://nws.caseyjhand.com/mcp \
  -H "Content-Type: application/json" \
  -H "MCP-Protocol-Version: 2025-11-25" \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-11-25","capabilities":{},"clientInfo":{"name":"curl","version":"1.0.0"}}}'

Built on@cyanheads/mcp-ts-core v0.9.21

Tools

Search active weather alerts (watches, warnings, advisories) across the US. Filter by state, coordinates, zone, event type, severity, urgency, or certainty. area, point, and zone are mutually exclusive. Omit all filters for a national search.

read

invocation

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "nws_search_alerts",
    "arguments": {}
  }
}

schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "area": {
      "description": "US state/territory code (e.g., \"WA\", \"OK\", \"PR\") or marine area code (e.g., \"GM\"). Mutually exclusive with point and zone.",
      "type": "string"
    },
    "point": {
      "description": "Coordinates as \"lat,lon\" (e.g., \"47.6,-122.3\"). Returns alerts whose geometry contains this point. Mutually exclusive with area and zone.",
      "type": "string"
    },
    "zone": {
      "description": "NWS forecast zone (e.g., \"WAZ558\") or county zone (e.g., \"WAC033\"). Mutually exclusive with area and point.",
      "type": "string"
    },
    "event": {
      "description": "Filter to specific event types (e.g., [\"Tornado Warning\"]). Matches are case-insensitive and partial, so \"tornado\" matches both \"Tornado Warning\" and \"Tornado Watch\". Use nws_list_alert_types to discover valid names.",
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "severity": {
      "description": "Filter by severity level.",
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "Extreme",
          "Severe",
          "Moderate",
          "Minor",
          "Unknown"
        ]
      }
    },
    "urgency": {
      "description": "Filter by urgency level.",
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "Immediate",
          "Expected",
          "Future",
          "Past"
        ]
      }
    },
    "certainty": {
      "description": "Filter by certainty level.",
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "Observed",
          "Likely",
          "Possible",
          "Unlikely",
          "Unknown"
        ]
      }
    },
    "status": {
      "default": "Actual",
      "description": "Alert status filter. Default \"Actual\". Use a different value only when you specifically need non-live alerts.",
      "type": "string",
      "enum": [
        "Actual",
        "Exercise",
        "System",
        "Test",
        "Draft"
      ]
    }
  },
  "required": [
    "status"
  ],
  "additionalProperties": false
}

view source ↗

nws_get_observations

Get current weather observations (actual measured conditions). Accepts coordinates (resolves nearest station automatically) or a station ID directly (e.g., "KSEA").

read

invocation

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "nws_get_observations",
    "arguments": {}
  }
}

schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "latitude": {
      "description": "Latitude for automatic station resolution. Use with longitude. Ignored if station_id is provided.",
      "type": "number",
      "minimum": -90,
      "maximum": 90
    },
    "longitude": {
      "description": "Longitude for automatic station resolution. Use with latitude. Ignored if station_id is provided.",
      "type": "number",
      "minimum": -180,
      "maximum": 180
    },
    "station_id": {
      "description": "Station identifier directly (e.g., \"KSEA\", \"KORD\"). Use nws_find_stations to discover station IDs.",
      "type": "string"
    }
  },
  "additionalProperties": false
}

view source ↗

nws_find_stations

Find weather observation stations near a location. Returns stations sorted by proximity with distance and bearing. Use to discover station IDs for nws_get_observations.

read

invocation

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "nws_find_stations",
    "arguments": {
      "latitude": "<latitude>",
      "longitude": "<longitude>"
    }
  }
}

schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "latitude": {
      "type": "number",
      "minimum": -90,
      "maximum": 90,
      "description": "Center latitude for proximity search."
    },
    "longitude": {
      "type": "number",
      "minimum": -180,
      "maximum": 180,
      "description": "Center longitude for proximity search."
    },
    "limit": {
      "default": 10,
      "description": "Max stations to return (1-50).",
      "type": "integer",
      "minimum": 1,
      "maximum": 50
    }
  },
  "required": [
    "latitude",
    "longitude",
    "limit"
  ],
  "additionalProperties": false
}

view source ↗

nws_list_alert_types

List all valid NWS alert event type names. Use to discover valid values for the event filter in nws_search_alerts, or to browse alert categories. No parameters required.

read

invocation

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "nws_list_alert_types",
    "arguments": {}
  }
}

schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {},
  "additionalProperties": false
}

view source ↗

nws_get_office_discussion

Get the latest narrative forecast product from a Weather Forecast Office (WFO). The default product is AFD (Area Forecast Discussion), which explains the meteorological reasoning behind the forecast — synoptic setup, model guidance, and forecaster confidence. Other types: HWO (Hazardous Weather Outlook, 1-7 day severe/flood/winter outlook), ZFP (Zone Forecast Product, zone-by-zone text), SPS (Special Weather Statement, short-fuse advisory). The office code is the 3-letter WFO identifier returned as the "office" field by nws_get_forecast. Fetches the two-hop products API: list endpoint first (newest product), then the full product detail.

read

invocation

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "nws_get_office_discussion",
    "arguments": {
      "office": "<office>"
    }
  }
}

schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "office": {
      "type": "string",
      "minLength": 1,
      "description": "Three-letter Weather Forecast Office (WFO) code (e.g., \"SEW\" for Seattle, \"LOX\" for Los Angeles). Returned as the \"office\" field in nws_get_forecast output."
    },
    "product_type": {
      "default": "AFD",
      "description": "Product type code. AFD (Area Forecast Discussion) — meteorological reasoning, model analysis, forecaster confidence. HWO (Hazardous Weather Outlook) — 1-7 day outlook for severe weather, flooding, winter weather. ZFP (Zone Forecast Product) — detailed zone-by-zone text forecast. SPS (Special Weather Statement) — short-fuse advisory for notable non-warning weather.",
      "type": "string",
      "enum": [
        "AFD",
        "HWO",
        "ZFP",
        "SPS"
      ]
    }
  },
  "required": [
    "office",
    "product_type"
  ],
  "additionalProperties": false
}

view source ↗

nws_get_zone_forecast

Get the text forecast for a public NWS forecast zone. Returns named forecast periods (e.g., "Today", "Tonight", "Monday") with detailed narrative text — the human-readable, zone-level forecast written by local forecasters. Completes the alert-to-forecast chain: nws_search_alerts returns zone codes in "affectedZones", and nws_find_stations returns them in the "forecastZone" column; use those codes here. Zone codes follow the pattern XXZ### (e.g., "WAZ315" for Western Washington lowlands). County zone codes (XXC###) are not supported — use the forecast zone code.

read

invocation

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "nws_get_zone_forecast",
    "arguments": {
      "zone_id": "<zone_id>"
    }
  }
}

schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "zone_id": {
      "type": "string",
      "minLength": 1,
      "description": "NWS public forecast zone code (e.g., \"WAZ315\" for the Western Washington lowlands including Seattle). Returned as \"forecastZone\" by nws_get_forecast and nws_find_stations, or in \"affectedZones\" by nws_search_alerts. Format: two-letter state + \"Z\" + three-digit number."
    }
  },
  "required": [
    "zone_id"
  ],
  "additionalProperties": false
}

view source ↗

Resources

NWS Alert Event Types

Static list of all valid NWS alert event type names. Useful reference when constructing event filters for nws_search_alerts.

uri nws://alert-types mime application/json