Right now
The most recent data we hold from NOAA arrived 2 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
This alert expired on 18 May 2026 at 16:30 UTC. It is kept here as a record.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 18 at 11:07AM CDT until May 18 at 11:30AM CDT by NWS Chicago IL
Urban PEI: 7,118,139 within a heuristic 50 km radius; not unique people.
How we know
3 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 52 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 52 / 100 |
| Legacy data-support index | 0.91/1 |
| Coordinates | 41.7583, -87.5406 |
| Nearest City | South Chicago (2 km) |
| Urban exposure index (PEI) | 7.1M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T16:07:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.9e4085815df95a5f4cde7102f577078248972e55.001.1 |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-05-18T16:07:00.000Z.
First archived: 2026-05-18T16:15:12.974Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Cook, IL; Lake, IN |
| Headline | Severe Thunderstorm Warning issued May 18 at 11:07AM CDT until May 18 at 11:30AM CDT by NWS Chicago IL |
| Expires | 2026-05-18T11:30:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| Google News RssFeed | weather |
| Google News SourceName | NBC 5 Chicago |
| MergedSources | [{"id":"gnews_weather_494197_150","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779110226000,"latitude":41.85,"longitude":-87.65},{"id":"gnews_weather_494197_169","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779110709000,"latitude":41.85,"longitude":-87.65}] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Review the area, threshold and delivery channel in your account.
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