This alert expired on 18 May 2026 at 20:45 UTC. It is kept here as a record.
It is the 9th strongest of the 26 detections recorded within 20 km of this point since 18 May 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 May 18 at 4:35PM EDT until May 18 at 4:45PM EDT by NWS Baltimore MD/Washington DC
Nearby, since 18 May 2026
- July 4, 2026 · score 34 · 7.0 km
- July 4, 2026 · score 34 · 9.8 km
- July 21, 2026 · score 58 · 17.2 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 22 out of 100, at 59 % 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) | 22 / 100 |
| Our confidence | 59% |
| Coordinates | 39.0829, -78.7357 |
| Nearest City | Front Royal (51 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-18T20:35:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.7ad8d06ae51b11c00db330c74dbe801961090b50.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Frederick, VA; Shenandoah, VA; Hampshire, WV; Hardy, WV |
| Headline | Severe Thunderstorm Warning issued May 18 at 4:35PM EDT until May 18 at 4:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-05-18T16:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
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 22/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.