This alert expired on 27 June 2026 at 21:45 UTC. It is kept here as a record.
It is the 29th strongest of the 41 detections recorded within 20 km of this point since 16 March 2026. Another comparable one was recorded here earlier the same day. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 27 at 5:16PM EDT until June 27 at 5:45PM EDT by NWS Greenville-Spartanburg SC
An estimated 71,548 people live within 50 km of this point.
Nearby, since 16 March 2026
- June 28, 2026 · score 43 · 10.2 km
- July 5, 2026 · score 43 · 11.6 km
- August 2, 2026 · score 43 · 13.8 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 32 out of 100, at 81 % 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) | 32 / 100 |
| Our confidence | 81% |
| Coordinates | 34.7329, -81.3994 |
| Nearest City | Rock Hill (40 km) |
| Population Exposed | 71.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-27T21:16:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Chester, SC; York, SC |
| Headline | Severe Thunderstorm Warning issued June 27 at 5:16PM EDT until June 27 at 5:45PM EDT by NWS Greenville-Spartanburg SC |
| Expires | 2026-06-27T17:45:00-04:00 |
| SenderName | NWS Greenville-Spartanburg SC |
| HasExactCoords | true |
| Iem TypeSummary | D |
| Iem City | 1 NW Clinton |
| Iem County | Laurens |
| Iem State | SC |
| Iem Wfo | GSP |
| Iem Remark | Tree downed in the Clinton area. |
| MergedSources | [{"id":"iem_D_34.480_-81.880_1782592440000","source":"iem","severity":"low","severityValue":25,"timestamp":1782592440000,"latitude":34.48,"longitude":-81.88}] |
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 32/100, near Rock Hill (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.