get_forecast
Retrieve weather forecasts for specific locations using latitude and longitude coordinates. This tool provides detailed weather predictions to help plan activities and prepare for conditions.
Instructions
Get weather forecast for a location.
Args:
latitude: Latitude of the location
longitude: Longitude of the locationInput Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| latitude | Yes | ||
| longitude | Yes |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Implementation Reference
- weather.py:171-294 (handler)The @mcp.tool()-decorated handler function that implements the core logic for fetching and formatting the weather forecast from the National Weather Service (NWS) API using latitude and longitude coordinates.
@mcp.tool() async def get_forecast(latitude: float, longitude: float, ctx: Context[ServerSession, None]) -> str: """Get weather forecast for a location. Args: latitude: Latitude of the location longitude: Longitude of the location """ await ctx.info(f"Fetching weather forecast for coordinates: {latitude}, {longitude}") logger.info(f"Processing forecast request for coordinates: {latitude}, {longitude}") # Validate coordinates if not (-90 <= latitude <= 90): error_msg = f"Invalid latitude: {latitude}. Must be between -90 and 90." await ctx.warning(error_msg) logger.warning(error_msg) return "Error: Latitude must be between -90 and 90 degrees." if not (-180 <= longitude <= 180): error_msg = f"Invalid longitude: {longitude}. Must be between -180 and 180." await ctx.warning(error_msg) logger.warning(error_msg) return "Error: Longitude must be between -180 and 180 degrees." # Step 1: Get the forecast grid endpoint await ctx.debug("Step 1: Getting forecast grid endpoint from NWS points API") points_url = f"{NWS_API_BASE}/points/{latitude},{longitude}" await ctx.report_progress( progress=0.3, total=1.0, message="Getting grid information..." ) points_data = await make_nws_request(points_url, ctx) if not points_data: error_msg = f"Unable to fetch forecast grid data for coordinates: {latitude}, {longitude}" await ctx.error(error_msg) logger.error(error_msg) return "Unable to fetch forecast data for this location." try: # Get the forecast URL from the points response forecast_url = points_data["properties"]["forecast"] await ctx.debug(f"Retrieved forecast URL: {forecast_url}") logger.debug(f"Forecast URL: {forecast_url}") except KeyError: error_msg = f"Invalid points response format for coordinates: {latitude}, {longitude}" await ctx.error(error_msg) logger.error(error_msg) return "Invalid response format from weather service points API." # Step 2: Get the detailed forecast await ctx.debug("Step 2: Getting detailed forecast data") await ctx.report_progress( progress=0.6, total=1.0, message="Fetching detailed forecast..." ) forecast_data = await make_nws_request(forecast_url, ctx) if not forecast_data: error_msg = f"Unable to fetch detailed forecast for coordinates: {latitude}, {longitude}" await ctx.error(error_msg) logger.error(error_msg) return "Unable to fetch detailed forecast." try: # Format the periods into a readable forecast periods = forecast_data["properties"]["periods"] if not periods: await ctx.warning(f"No forecast periods available for coordinates: {latitude}, {longitude}") logger.warning(f"No forecast periods for coordinates: {latitude}, {longitude}") return "No forecast periods available for this location." period_count = min(len(periods), 5) # Only show next 5 periods await ctx.info(f"Processing {period_count} forecast periods") logger.info(f"Processing {period_count} forecast periods") await ctx.report_progress( progress=0.8, total=1.0, message=f"Formatting {period_count} forecast periods..." ) forecasts = [] for i, period in enumerate(periods[:5]): forecast = f""" {period['name']}: Temperature: {period['temperature']}°{period['temperatureUnit']} Wind: {period['windSpeed']} {period['windDirection']} Forecast: {period['detailedForecast']} """ forecasts.append(forecast) # Report progress for each period processed progress = 0.8 + (0.2 * (i + 1) / period_count) await ctx.report_progress( progress=progress, total=1.0, message=f"Processed period {i + 1}/{period_count}" ) await ctx.info(f"Successfully processed forecast for coordinates: {latitude}, {longitude}") logger.info(f"Successfully processed forecast for coordinates: {latitude}, {longitude}") return "\n---\n".join(forecasts) except KeyError as e: error_msg = f"Missing required field in forecast data: {e}" await ctx.error(error_msg) logger.exception("Missing required field in forecast data") return "Error: Invalid forecast data format." except Exception: error_msg = f"Unexpected error processing forecast for coordinates: {latitude}, {longitude}" await ctx.error(error_msg) logger.exception("Unexpected error processing forecast") return "Error: Could not process forecast data." - weather.py:26-72 (helper)Shared helper function used by get_forecast (and get_alerts) to make authenticated HTTP requests to the NWS API with comprehensive error handling and MCP context logging.
async def make_nws_request(url: str, ctx: Context[ServerSession, None] | None = None) -> dict[str, Any] | None: """Make a request to the NWS API with proper error handling.""" headers = {"User-Agent": USER_AGENT, "Accept": "application/geo+json"} if ctx: await ctx.debug(f"Making NWS API request to: {url}") logger.debug(f"Making request to NWS API: {url}") async with httpx.AsyncClient(follow_redirects=True) as client: try: response = await client.get(url, headers=headers, timeout=30.0) response.raise_for_status() if ctx: await ctx.debug(f"NWS API request successful, status: {response.status_code}") logger.debug(f"NWS API request successful: {response.status_code}") return response.json() except httpx.TimeoutException: error_msg = f"Request timeout for URL: {url}" if ctx: await ctx.error(error_msg) logger.exception("Request timeout occurred") return None except httpx.HTTPStatusError as e: error_msg = f"HTTP error {e.response.status_code} for URL: {url}" if ctx: await ctx.error(error_msg) logger.exception("HTTP status error occurred") return None except httpx.RequestError: error_msg = f"Network error for URL: {url}" if ctx: await ctx.error(error_msg) logger.exception("Network request error occurred") return None except Exception: error_msg = f"Unexpected error for URL: {url}" if ctx: await ctx.error(error_msg) logger.exception("Unexpected error during NWS API request") return None - weather.py:307-307 (registration)List of available tools including get_forecast, exposed via the server_info tool.
"available_tools": ["get_alerts", "get_forecast", "server_info"],