This alert expired on 22 July 2026 at 00:15 UTC. It is kept here as a record.
It is the 19th strongest of the 36 detections recorded within 20 km of this point since 12 March 2026. The last comparable one was on 7 July 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 21 at 7:44PM EDT until July 21 at 8:15PM EDT by NWS Baltimore MD/Washington DC
An estimated 15,070 people live within 50 km of this point.
Nearby, since 12 March 2026
- July 21, 2026 · score 63 · 13.6 km
- July 7, 2026 · score 28 · 14.2 km
- July 4, 2026 · score 39 · 19.3 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 28 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) | 28 / 100 |
| Our confidence | 80% |
| Coordinates | 38.8717, -78.5921 |
| Nearest City | Front Royal (35 km) |
| Population Exposed | 15.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-21T23:44:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.ba75989e0b406f3d652ba053df47b537 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Montgomery, MD; Loudoun, VA; Clarke, VA; Frederick, VA; Shenandoah, VA; Warren, VA; City of Winchester, VA; Page, VA; Rockingham, VA; Shenandoah, VA; Grant, WV; Hardy, WV; Pendleton, WV and 1 more areas |
| Headline | Severe Thunderstorm Warning issued July 21 at 7:44PM EDT until July 21 at 8:15PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-07-21T20:15:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.ba75989e0b406f3d652ba053df47b537a8073f50.001.1","noaa_urn:oid:2.49.0.1.840.0.c8e441d186dda370bb036431e55ae5cbcfe30fc7.001.1","noaa_urn:oid:2.49.0.1.840.0.cdf60e13cd2a4be36ae17baf49e962abfc3462be.001.1","noaa_urn:oid:2.49.0.1.840.0.bb60a43acffa8da1562f0649e2f972ecb9be72d1.002.1"] |
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 28/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.