880
NOUS41 KWBC 221850
PNSWSH

Service Change Notice 25-44
National Weather Service Headquarters Silver Spring MD
450 PM EDT Thu May 22, 2025

TO: SUBSCRIBERS:
 -NOAA Weather Wire Service
 -Emergenc Managers Weather Information Network
 -NOAAPort
 Other NWS Partners, Users and NWS Employees

FROM: Dave Michaud
 Director, NCEP Central Operations (NCO)

SUBJECT:  Upgrade NWS API Website forecast and alerts endpoints
Effective: May 22, 2025

On May 22, 2025 at 1800 Universal Coordinated Time (UTC), the
National Weather Service API Application Programming Interface
(Website) was upgraded to version 2.5. With this upgrade comes
the following user-impactful changes:

1. Add Station Name to the stations/XXXX/observations endpoint

Example:
https://api.weather.gov/stations/KPHL/observations/latest

2. Add missing CAP fields to individual alerts.  More about CAP
can be found at:
https://vlab.noaa.gov/web/nws-common-alerting-protocol

    
    
    
    
    

3. Limit option now works for observations

Example:
https://api.weather.gov/gridpoints/REV/33,79/stations?limit=1

4. Added CAP product latency to API Health check

Go to https://api.weather.gov/health to see this addition for
NGITWS_CAP_METADATA and for individual alerts as well for
approximately the last 60 minutes.

5. Properly implement the DWML/XML output data in the
/gridpoints/{wfo}/{x},{y}/forecast/hourly endpoint.  Any code
previously utilizing the DWML output option from this endpoint
will need to be adjusted.

6. Data in the /gridpoints/{wfo}/{x},{y}/forecast/hourly
endpoint will now display null values for missing data instead
of returning a 503 error.

7. Individual alert eventEndingTime parameter in the alerts
endpoints now defaults to local time offset instead of UTC
offset.

8. Requesting an invalid gridpoints gridX,gridY URL in any
gridpoints endpoint will now result in a 404 error instead of a
500 error.

9. JSON properties for gridX and gridY values in the
/gridpoints/{wfo}/{x},{y} endpoint are now properly returned as
integers instead of strings, the same as the points endpoint and
as referenced in the OpenAPI specification.

10. Forecast probabilityOfPrecipitation values less than 20 no
longer display null values in the
/gridpoints/{wfo}/{x},{y}/forecast endpoint.  A raw maximum
value for the 12h period is returned instead.

11. MADIS null wind direction values may be reported in the wind
direction and wind_string fields of the XML output from
observations endpoints, instead of returning a 500 error.

12. Correct discrepancies in the /alerts/types endpoint to align
with the latest Hazards Map standards at
https://www.weather.go/help-map

13. Feature flag obs_station_provider added to display MADIS
provider and subProvider data in the stations endpoints.

14. Added /products/types/{typeId}/locations/{locationId}/latest
endpoint to obtain the latest of any text product type and
location.


For operational issues on the API Website, please contact:

NCEP Central Operations
Tech Control
nco.ops@noaa.gov

For technical questions regarding this notification, please
contact:

Software Development Branch
NWS Office of Dissemination
sdb.support@noaa.gov

National Service Change Notices are online at:

https://www.weather.gov/notification