This alert expired on 28 June 2026 at 20:00 UTC. It is kept here as a record.
It is the 4th strongest of the 53 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day. 4 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 28 at 3:49PM EDT until June 28 at 4:00PM EDT by NWS Greenville-Spartanburg SC
An estimated 189,192 people live within 50 km of this point.
Nearby, since 12 March 2026
- July 24, 2026 · score 43 · 8.9 km
- June 1, 2026 · score 39 · 15.8 km
- March 13, 2026 · score 52 · 16.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 out of 100, at 80 % 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) | 43 / 100 |
| Our confidence | 80% |
| Coordinates | 34.7413, -80.9152 |
| Nearest City | Rock Hill (22 km) |
| Population Exposed | 189.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-28T19:49:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Chester, SC; York, SC; Lancaster, SC |
| Headline | Severe Thunderstorm Warning issued June 28 at 3:49PM EDT until June 28 at 4:00PM EDT by NWS Greenville-Spartanburg SC |
| Expires | 2026-06-28T16:00:00-04:00 |
| SenderName | NWS Greenville-Spartanburg SC |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.05920e945713d26e0fa8deccbdafa12219bcb824.001.1","noaa_urn:oid:2.49.0.1.840.0.21bf73ab5a82ca81650467db37c239370fb5f6c9.001.1","noaa_urn:oid:2.49.0.1.840.0.b4ca49ea952da72505bd6bc34e09c1afaec21a2b.001.1"] |
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 43/100, near Rock Hill (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.