Right now
The most recent data we hold from NOAA arrived 9 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 18 May 2026 at 21:45 UTC. It is kept here as a record.
It is the 2nd strongest of the 22 detections recorded within 20 km of this point since 13 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 5:17PM EDT until May 18 at 5:45PM EDT by NWS Baltimore MD/Washington DC
An estimated 65,114 people live within 50 km of this point.
Nearby, since 13 May 2026
- June 14, 2026 · score 39 · 1.4 km
- August 6, 2026 · score 39 · 11.3 km
- May 18, 2026 · score 43 · 23.4 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 39 out of 100, at 79 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 39 / 100 |
| Our confidence | 79% |
| Coordinates | 39.4220, -78.2910 |
| Nearest City | Winchester (28 km) |
| Population Exposed | 65.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T21:17:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.be21f5fcf0b3dd61802ea1237d69582c |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Clarke, VA; Frederick, VA; Shenandoah, VA; City of Winchester, VA; Hampshire, WV; Allegany, MD; Washington, MD |
| Headline | Severe Thunderstorm Warning issued May 18 at 5:17PM EDT until May 18 at 5:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-05-18T17:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.be21f5fcf0b3dd61802ea1237d69582ceb3f6cc6.001.1","noaa_urn:oid:2.49.0.1.840.0.6470a6c56dc74b844ab83e629176cb63df959df1.001.1"] |
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 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.
Want to know when something happens near Winchester?
Calamity.live data shows a weather event with CalamityScore 39/100, near Winchester (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.