A practical MCP workflow

Review US weather forecasts with an AI agent and MCP

Choose public US coordinates you intend to share with NWS. Call nws_point to resolve the current forecast office and grid, then use that exact grid with nws_grid_forecast and nws_hourly_forecast. Keep generated, updated and valid times, period start/end times, source units and null values with your planning brief. Recheck current official information before decisions.

Built for: People planning outdoor events or trips at NWS-covered US locations.

What to connect

Create a ToolCargo account and use OAuth or an API key with a supported MCP client. Hosted connectors share your plan’s call quota; connect each required MCP endpoint separately. Review provider permissions before starting.

NWS Weather Planning

Client setup and test status · Current plans and limits

Run the workflow

1. Resolve the location you intend to share
Use nws_point with latitude and longitude. ToolCargo rounds to four decimal places and sends the coordinates to NWS; a public landmark is a useful starting point. Read the returned location, grid office and grid rather than assuming city-wide or address-level precision. Keep the issuing forecast office separate; in Alaska it can differ from the grid office.
2. Read the dated period forecast
Pass the exact office, gridX and gridY to nws_grid_forecast and choose units us or si. Keep source updateTime and validTimes separate from fetchedAt: fetching now does not mean the underlying forecast was issued now. Grid mappings can change, so resolve the point again for later sessions.
3. Compare the relevant hourly periods
Use nws_hourly_forecast for the same grid and unit choice. Read startTime and endTime with their source timezone offsets. Use nextOffset explicitly when more periods are needed; bounded pages do not imply a complete weather picture.
4. Preserve uncertainty in the planning brief
Keep numerical probability units, raw wind-speed ranges and the source's text forecast together. Null means missing rather than no rain. A grid forecast is a forecast for an area, not an observation at your point. Revisit current official forecasts and guidance before decisions.

A prompt to try

For the public location at latitude 38.8977, longitude -77.0365, resolve its NWS forecast grid, then inspect the first period and hourly forecast pages in SI units. Show source update and valid times, period times, temperature units, wind-speed text and precipitation probabilities. Keep missing values explicit and link the original forecast. Explain the grid coverage and what needs rechecking before our outdoor event.

What a useful result looks like

Chosen public coordinates → resolved forecast office/grid → source issue/update/valid times → selected period and hourly windows → temperature and wind units → precipitation probabilities or missing values → source links and recheck time. Keep the forecast distinct from current measured conditions.

Know the limits

NWS coverage is geographically limited and forecast grids cover areas. The source can be delayed, missing or revised; separate calls do not form a pinned snapshot. This connector does not read observations, alerts, marine forecasts or radar. It is an on-demand planning aid with explicit pages, not a monitoring or emergency service.

Common questions

Does this cover Egypt or Saudi Arabia?

No. The NWS point/grid endpoints cover supported US locations. An unsupported point returns a coverage or availability error; ToolCargo does not invent a forecast.

Is a missing rain probability zero?

No. Preserve null as missing data. The source text may describe conditions separately and should be read alongside the numeric probability.

Does fetching now guarantee a new forecast?

No. fetchedAt records the lookup time; updateTime and validTimes describe the source forecast. Forecasts can change, so recheck before decisions.

References and tool documentation

Use the provider’s documentation to check the underlying concepts, and ToolCargo’s references for the exact tools, inputs and limits.

NWS API documentation
Review free public access, identifying User-Agent, point-to-grid mapping, forecast endpoints and source limits.
NWS API specification
Check point, grid forecast and hourly forecast parameter and response contracts.

Review US weather forecasts with an AI agent and MCP

What to connect

Run the workflow

1. Resolve the location you intend to share

2. Read the dated period forecast

3. Compare the relevant hourly periods

4. Preserve uncertainty in the planning brief