Winter Storm Sample

This page provides a complete sample response for a winter storm hazard from the Active Hazards API endpoint. Winter storm hazards encompass snowfall warnings, blizzards, and ice storms, and are typically sourced from national weather agencies such as Environment Canada, the U.S. National Weather Service (NWS), and the Australian Government Bureau of Meteorology (BoM). These alerts follow the Common Alerting Protocol (CAP) standard.

Winter Storm-Specific Properties

Incident Data

The incident.properties object for a winter storm contains CAP-based alert metadata describing the weather warning. Key incident properties for winter storms include:

• event - The specific weather event type (e.g., "Snowfall")

• headlineDescription - Full descriptive headline combining alert status and detailed forecast information

• hazardSeverity - The severity classification of the hazard (e.g., "WARNING")

• incidentLocationName - Human-readable location of the alert (e.g., "North Battleford, Saskatchewan, Canada")

• senderName - Issuing agency (e.g., "Environment Canada")

• headline - Alert headline text (e.g., "yellow warning - Snowfall - in effect")

• description - Detailed alert description with snowfall accumulation amounts and travel impacts

• severity - CAP severity level (e.g., "Moderate")

• urgency - CAP urgency level (e.g., "Future, Immediate")

• certainty - CAP certainty level (e.g., "Likely, Unknown")

• effective / expires / onset - ISO 8601 timing fields for the alert window

• msgType - CAP message type (e.g., "Update")

• instruction - Recommended actions (e.g., "Prepare for quickly changing and deteriorating travel conditions.")

• category - CAP category (e.g., "Met" for meteorological)

Features

The features property contains a GeoJSON FeatureCollection with CAP_INFO features. Each CAP_INFO feature represents an individual alert info block from the original CAP message, containing the alert polygon geometry along with area descriptions and geocodes. Winter storm alerts may also include SMART_ALERT and EXPOSURE_AREA features within the same collection.

Exposure Areas

Winter storm hazards use a single exposure level representing the source-provided alert area:

• Level 1: Source-provided alert area - the geographic region covered by the weather warning

Sample Response

{
  "name": [
    {
      "locale": "en",
      "value": "Snowfall - North Battleford, Saskatchewan, Canada"
    }
  ],
  "description": [
    {
      "locale": "en",
      "value": "Environment Canada has issued a Snowfall warning for February 16, 2026 11:12:08 UTC through February 17, 2026 08:12:37 UTC.\n\nIt is estimated that 47,200 people, 20,700 households, and $6.34 Billion (USD) of infrastructure* are within the affected area(s). Exposure estimates will be refined as additional data from official sources becomes available.\n\nyellow warning - Snowfall - in effect\nA long period of Snowfall with total amounts of 15 to 25 cm is expected. A band of heavy snow will push into west-central Saskatchewan beginning Monday night. Generally, 10-15 cm of snow is expected on Tue..."
    }
  ],
  "severity": "WARNING",
  "category": "EVENT",
  "incident": {
    "uuid": "0061711f-cf0b-4ff0-8cc4-72f93da50f83",
    "type": "WINTERSTORM",
    "sourceId": 1800,
    "sourceRecordId": "urn:oid:2.49.0.1.124.1926260591.2026",
    "properties": {
      "expires": "2026-02-17T08:12:37Z",
      "msgType": "Update",
      "code": "layer:SOREM:2.0",
      "hazardName": "Snowfall - North Battleford, Saskatchewan, Canada",
      "description": "A long period of Snowfall with total amounts of 15 to 25 cm is expected. A band of heavy snow will push into west-central Saskatchewan beginning Monday night. Generally, 10-15 cm of snow is expected on Tue...",
      "effective": "2026-02-16T11:12:08Z",
      "senderName": "Environment Canada",
      "urgency": "Future, Immediate",
      "scope": "Public",
      "hazardSeverity": "WARNING",
      "event": "Snowfall",
      "headline": "yellow warning - Snowfall - in effect\nyellow warning - Snowfall - changed",
      "severity": "Moderate",
      "headlineDescription": "yellow warning - Snowfall - in effect\nA long period of Snowfall with total amounts of 15 to 25 cm is expected...",
      "identifier": "urn:oid:2.49.0.1.124.2868569842.2026",
      "incidentLocationName": "North Battleford, Saskatchewan, Canada",
      "certainty": "Likely, Unknown",
      "onset": "2026-02-17T06:00:00Z",
      "sender": "[email protected]",
      "instruction": "\nPrepare for quickly changing and deteriorating travel conditions.\n",
      "category": "Met",
      "status": "Actual",
      "..."
    }
  },
  "uuid": "bab35873-3696-4e23-85c9-01863ce78a19",
  "comment": null,
  "createdAt": 1771277569,
  "relatedHazards": [],
  "longitude": -108.64495,
  "latitude": 53.43538,
  "version": 3,
  "alertGeometry": {
    "type": "FeatureCollection",
    "features": [
      {
        "type": "Feature",
        "geometry": {
          "type": "Polygon",
          "coordinates": [...]
        },
        "properties": null
      }
    ]
  },
  "features": {
    "features": [
      {
        "id": null,
        "type": "Feature",
        "properties": {
          "severity": "Moderate",
          "area": [
            {
              "areaDesc": "R.M. of Frenchman Butte including St. Walburg",
              "polygon": ["..."],
              "geocode": [
                {
                  "valueName": "layer:EC-MSC-SMC:1.0:CLC",
                  "value": "066211"
                },
                {
                  "valueName": "profile:CAP-CP:Location:0.3",
                  "value": "4717032"
                }
              ]
            }
          ],
          "type": "CAP_INFO",
          "featureType": "CAP_INFO",
          "isCancellation": false,
          "..."
        },
        "incidentType": null,
        "sourceId": null
      },
      {
        "id": null,
        "type": "Feature",
        "properties": {
          "featureType": "SMART_ALERT",
          "type": "SMART_ALERT"
        },
        "geometry": {
          "type": "Polygon",
          "coordinates": [...]
        },
        "incidentType": null,
        "sourceId": null
      },
      {
        "id": null,
        "type": "Feature",
        "properties": {
          "severity": "LIMITED",
          "featureType": "EXPOSURE_AREA",
          "type": "EXPOSURE_AREA"
        },
        "geometry": {
          "type": "Polygon",
          "coordinates": [...]
        },
        "incidentType": null,
        "sourceId": null
      }
    ],
    "incidentType": null,
    "metadata": null,
    "type": "FeatureCollection",
    "sourceId": null
  },
  "exposureAreas": {
    "features": [
      {
        "id": null,
        "type": "Feature",
        "properties": {
          "exposureLevel": 1
        },
        "geometry": {
          "type": "Polygon",
          "coordinates": [...]
        },
        "sourceId": null
      }
    ],
    "type": "FeatureCollection"
  },
  "exposureAssessment": {
    "population": 47200.0,
    "capital": 6349902600.0,
    "exposureLevels": [
      {
        "level": "1",
        "data": {
          "population": 47200.0,
          "capital": 6349902600.0,
          "foodNeedsUnit": "CAL",
          "foodNeeds": 9912000.0,
          "waterNeedsUnit": "liter",
          "waterNeeds": 14160.0,
          "wasteNeedsUnit": "100 liter",
          "wasteNeeds": 472.0,
          "shelterNeedsUnit": "sq meters",
          "shelterNeeds": 16284.0
        },
        "exposureDescription": "LIMITED"
      }
    ],
    "hazardUuid": "",
    "hazardType": "",
    "version": "",
    "timestamp": "1771277547023",
    "exposureDescription": "",
    "foodNeedsUnit": "CAL",
    "foodNeeds": 9912000.0,
    "waterNeedsUnit": "liter",
    "waterNeeds": 14160.0,
    "wasteNeedsUnit": "100 liter",
    "wasteNeeds": 472.0,
    "shelterNeedsUnit": "sq meters",
    "shelterNeeds": 16284.0
  },
  "type": "WINTERSTORM",
  "creator": "RICHTER",
  "source": null,
  "startedAt": 1771240328,
  "updatedAt": 1771277546,
  "endedAt": 1771315957
}

Note: Coordinate arrays have been replaced with [...] for brevity. In actual API responses, these contain complete GeoJSON coordinate arrays. The incident.properties object has been truncated with "..." to show only key fields. The full response includes additional CAP metadata fields such as note, references, rawMessage, eventCode, and headlineDescription. The features collection includes multiple CAP_INFO area features (one per alert zone), only one of which is shown here.