So, is the weatherAlerts field ever populated? From my (limited experience) it does not populate with current NWS alerts.
Yes, one can get water alerts issued by the National Weather Service from WeatherKit. All you need to do is to specify weatherAlerts in your dataSets query parameter and include the country parameter indicating which government authority should be issuing the alert.
For example, I can get the currently active alert in San Francisco issued by the National Weather Service in the US by making an HTTP GET request with URL
https://weatherkit.apple.com/api/v1/weather/en-US/37.775/-122.419?dataSets=weatherAlerts&country=US&timezome=America/Los_Angeles
and I get back the following JSON response:
{
"weatherAlerts": {
"name": "WeatherAlertCollection",
"metadata": {
"attributionURL": "https://weatherkit.apple.com/legal-attributionl.html",
"expireTime": "2023-01-24T13:56:57Z",
"language": "en-US",
"latitude": 37.775,
"longitude": -122.419,
"providerName": "National Weather Service",
"readTime": "2023-01-24T13:51:57Z",
"reportedTime": "2023-01-24T13:51:57Z",
"version": 1
},
"detailsUrl": "https://weatherkit.apple.com/alertDetails/index.html?ids=aa2dc3b7-fed9-5440-a4eb-5016e5b7fcf6&lang=en-US&timezone=America/Los_Angeles",
"alerts": [
{
"name": "WeatherAlertSummary",
"id": "aa2dc3b7-fed9-5440-a4eb-5016e5b7fcf6",
"areaId": "caz006",
"areaName": "San Francisco",
"attributionURL": "https://alerts.weather.gov/cap/wwacapget.php?x=CA1266315CB698.BeachHazardsStatement.1266316AFFA0CA.MTRCFWMTR.37cfe8e9d94b8ab78ac93cb81ffbbd70",
"countryCode": "US",
"description": "Beach Hazards Statement",
"effectiveTime": "2023-01-24T12:38:00Z",
"expireTime": "2023-01-25T06:00:00Z",
"issuedTime": "2023-01-24T12:38:00Z",
"eventEndTime": "2023-01-25T06:00:00Z",
"detailsUrl": "https://weatherkit.apple.com/alertDetails/index.html?ids=aa2dc3b7-fed9-5440-a4eb-5016e5b7fcf6&lang=en-US&timezone=America/Los_Angeles",
"phenomenon": "Coastal",
"precedence": 0,
"severity": "moderate",
"source": "National Weather Service",
"eventSource": "US",
"urgency": "expected",
"certainty": "likely",
"importance": "normal",
"responses": []
}
]
}
}
A common problem is forgetting the country parameter. Weather alerts are official notices issued by government weather agencies and sometimes more than one government will issue alerts for the same location for reasons outside of Apple's control, so it is necessary to specify the country as well as the location.