Right now
The most recent data we hold from NOAA arrived 3 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 27 June 2026 at 21:45 UTC. It is kept here as a record.
It is the 45th strongest of the 56 detections recorded within 20 km of this point since 16 March 2026. The last comparable one was on 1 June 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 27 at 4:42PM EDT until June 27 at 5:45PM EDT by NWS Greenville-Spartanburg SC
Urban PEI: 71,548 within a heuristic 50 km radius; not unique people.
Nearby, since 16 March 2026
- June 27, 2026 · score 32 · 3.9 km
- June 28, 2026 · score 43 · 13.1 km
- August 2, 2026 · score 43 · 14.9 km
How we know
2 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 32 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) | 32 / 100 |
| Legacy data-support index | 0.82/1 |
| Coordinates | 34.7050, -81.3733 |
| Nearest City | Rock Hill (39 km) |
| Urban exposure index (PEI) | 71.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-27T20:42:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.8df2ec6e27edb245fe9bef33d2dc18c1d4d0702f.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: 2026-06-27T20:42:00.000Z.
First archived: 2026-06-27T21:14:14.148Z. 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 | Cherokee, SC; Chester, SC; Union, SC; York, SC |
| Headline | Severe Thunderstorm Warning issued June 27 at 4:42PM 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 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.
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