Do alerts need to be filtered?

[jhemak]

Hello! When I query my location using api.weather.gov I see two heat advisories. Everything seems the same except for the value of "expires" . When I query the same location using just about any weather site -- weather.com, weather.gov, wunderground, etc. I see only one heat advisory which is the one more recently issued. Obviously all these sites are somehow filtering out the second one, but I do not see anything in the API response that would tell me to use one and ignore the other. Any idea what logic others are using here?

[sullynole]

What is the request you are using?

[jhemak]

https://api.weather.gov/alerts/active.atom?zone=OHZ077%2COHC061

[jhemak]

I’m sorry, you are right. I made a mistake when I said heat vs air quality. Nonetheless, there must be some logic that weather.gov and the other user-facing sites are implementing - rather consistently - in order to remove the duplicates. Thanks for the insight though!

[sullynole]

Each agency's air quality alert criteria may be slightly different, but using the last issued in this case may work. Check on the issuance criteria to see if that makes sense.

[scadergit]

If you're curious, weather.gov and the API have different data flows. The office generates an alert as a text product. On one path, those are converted to CAP and ultimately feed the API. On another path, which is slowly geting replaced to the use API, the original text products are parsed and inserted into a database which utlimately feed weather.gov (which has no concept of CAP). The text product parsing for weather.gov has a long history of modifications to solve issues, including catching oddities in how text products are issued by the offices.

As for weather.com--no idea, they probably have their own method.

You might also reach out to the forecast office to ask why there were two identifical text products. I would think the second should have been an extension of the first, in which the API would only display the second.

[sullynole]

There is no VTEC in AQAs so that is the issue for CAP alert tracking. Agree it would be a good idea to reach out to the local office to find out if you can always use the latest one.

[jhemak]

Thanks, guys! This is very helpful!