National Weather Service Data: Using Forecasts for Planning and Research
Overview
The National Weather Service (NWS) publishes extensive, free weather data—forecasts, observations, alerts, radar, and model output—designed for public use. Planners, emergency managers, researchers, and developers can use these datasets to inform decisions, model impacts, and create tools.
Key NWS data sources and products
| Product | What it provides | Common uses |
|---|---|---|
| API (api.weather.gov) | Forecasts, alerts, observations, gridpoints, metadata in JSON/GeoJSON | Web/apps, automated alerting, point forecasts |
| National Digital Forecast Database (NDFD) | Gridded forecast fields (temperature, precipitation, wind, icons) | Spatial planning, GIS analysis, model validation |
| NDFD XML / REST / SOAP | DWML/TSML encodings, time-series for points | Interoperability with OGC tools, time-series extraction |
| Radar & MRMS products | Radar reflectivity, velocity, mosaic products | Nowcasting, severe-storm analysis |
| NCEI archives & model outputs | Historical observations, archived forecasts and models | Climate research, retrospective studies |
| Alerts/CAP feeds | Machine-readable watches, warnings, advisories | Emergency response, public-safety systems |
How to access data (practical steps)
- Use the NWS API:
- Base URL: https://api.weather.gov
- Typical flow: geocode address → /points/{lat},{lon} → follow “forecast” or gridpoints links returned.
- Include a descriptive User-Agent header (app name and contact).
- For gridded forecasts: download NDFD via NCEI services or the NDFD web services (GRIB2, TAR, or AWS Open Data).
- For radar/MRMS: use NWS OGC services, RIDGE2, or MRMS archives for display-quality data.
- For alerts: query /alerts or /alerts/active with filters (area, zone).
- For archived data or bulk downloads: consult NCEI and NOAA Big Data Program (cloud buckets on AWS/GCP).
Example use cases
- Emergency planning: ingest /alerts and NDFD precipitation/wind fields to run evacuation-impact models and resource staging.
- Infrastructure design: use historical extremes from NCEI plus NDFD probability fields to size drainage and power systems.
- Academic research: combine MRMS radar-derived rainfall with NDFD and station observations to evaluate convection-permitting model skill.
- App development: use /points → /gridpoints/{office}/{x,y}/forecast to display localized 12-hour or hourly forecasts.
Quick implementation example (conceptual)
- Step 1: Geocode location → get lat,lon.
- Step 2: GET https://api.weather.gov/points/{lat},{lon} (extract forecast and gridpoint URLs).
- Step 3: GET the forecast or gridpoint endpoint (parse JSON/GeoJSON).
- Step 4: Store results with timestamps, respect Cache-Control headers and update cadence.
Best practices
- Respect HTTP caching headers and NWS rate limits; cache /points results (grid mapping changes rarely).
- Set a clear User-Agent with contact info.
- Validate forecasts against local observations for bias correction before using in critical models.
- Combine multiple NWS sources (NDFD, radar, observations) for robust situational awareness.
- For reproducible research, archive the exact NWS product IDs/timestamps you used.
Resources
- NWS API documentation: https://www.weather.gov/documentation/services-web-api
- NDFD info and access: NCEI/NOAA NDFD pages (NDFD web services and GRIB2 resources)
- NDFD XML REST: https://digital.weather.gov/xml/
If you want, I can produce a short code snippet (Python or R) that fetches a point forecast and saves it to CSV.
Leave a Reply