This alert expired on 15 March 2026 at 21:30 UTC. It is kept here as a record.
It is the 6th strongest of the 29 detections recorded within 20 km of this point since 15 March 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued March 15 at 4:18PM CDT until March 15 at 4:30PM CDT by NWS St Louis MO
An estimated 689,137 people live within 50 km of this point.
Nearby, since 15 March 2026
- July 11, 2026 · score 52 · 3.3 km
- May 21, 2026 · score 48 · 4.0 km
- March 15, 2026 · score 72 · 4.6 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 48 out of 100, at 82 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 48 / 100 |
| Our confidence | 82% |
| Coordinates | 39.0254, -90.5227 |
| Nearest City | Saint Peters (27 km) |
| Population Exposed | 689.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-15T21:18:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe-Thunderstorm-Warning_noaa_urn-oid-2_49_0_1_840_0_3c4034027808dc96deb17c1fb9e35196 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Calhoun, IL; St. Charles, MO; Morgan, IL; Sangamon, IL; Scott, IL; Greene, IL; Jersey, IL and 1 more areas |
| Headline | Severe Thunderstorm Warning issued March 15 at 4:18PM CDT until March 15 at 4:30PM CDT by NWS St Louis MO |
| Expires | 2026-03-15T16:30:00-05:00 |
| SenderName | NWS St Louis MO |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.3c4034027808dc96deb17c1fb9e3519629b9db88.002.1","noaa_urn:oid:2.49.0.1.840.0.e5e8a99a80bfe675b0d99da813586d62b5991d01.001.1","noaa_urn:oid:2.49.0.1.840.0.d615cbf26fa75ee341a355b30393bf168be1d972.001.1","noaa_urn:oid:2.49.0.1.840.0.b07417d04adbe46202c7cd300d96374da7584cd0.002.1"] |
| Iem TypeSummary | D |
| Iem City | Troy |
| Iem County | Lincoln |
| Iem State | MO |
| Iem Wfo | LSX |
| Iem Remark | Tree down on East Cherry Street with live power lines on the roadway. |
| MergedSources | [{"id":"iem_D_38.980_-90.980_1773607140000","source":"iem","severity":"low","severityValue":25,"timestamp":1773607140000,"latitude":38.98,"longitude":-90.98}] |
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 10 February 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.
Calamity.live data shows a weather event with CalamityScore 48/100, near Saint Peters (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.