This alert expired on 10 August 2026 at 20:45 UTC. It is kept here as a record.
It is the 21st strongest of the 99 detections recorded within 20 km of this point since 16 March 2026. The last comparable one was on 8 August 2026. 17 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 10 at 4:33PM EDT until August 10 at 4:45PM EDT by NWS Mount Holly NJ
An estimated 985,361 people live within 50 km of this point.
Nearby, since 16 March 2026
- August 8, 2026 · score 52 · 8.6 km
- June 12, 2026 · score 48 · 8.7 km
- August 8, 2026 · score 43 · 13.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 48 out of 100, at 79 % 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) | 48 / 100 |
| Our confidence | 79% |
| Coordinates | 38.6296, -77.6687 |
| Nearest City | Linton Hall (17 km) |
| Population Exposed | 985.4K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-10T20:33:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.8c8b5c00d55af1527a9dfed1758ea45e |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Hunterdon, NJ; Morris, NJ; Warren, NJ; Cecil, MD; Harford, MD; District of Columbia, DC; Anne Arundel, MD; Howard, MD; Montgomery, MD; Prince Georges, MD; Arlington, VA; Fairfax, VA; Loudoun, VA; City of Alexandria, VA; City of Fairfax, VA; City of Falls Church, VA and 8 more areas |
| Headline | Severe Thunderstorm Warning issued August 10 at 4:33PM EDT until August 10 at 4:45PM EDT by NWS Mount Holly NJ |
| Expires | 2026-08-10T16:45:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 11 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.8c8b5c00d55af1527a9dfed1758ea45e182a140c.002.1","noaa_urn:oid:2.49.0.1.840.0.40aa3299c79c4164dba8439038ca558ded8a74ec.001.1","noaa_urn:oid:2.49.0.1.840.0.6ff2c29afc4e753a4d877d08d0d779de60e22c2f.001.1","noaa_urn:oid:2.49.0.1.840.0.cb62310e1c4d283b81489b3a8dff15bd3f531f8a.001.1","noaa_urn:oid:2.49.0.1.840.0.b4f64b959822447e166af70a087e984bfe38be85.002.1","noaa_urn:oid:2.49.0.1.840.0.9773de75d375bf72c89e41b85cd0e11bf2c1edef.001.1","noaa_urn:oid:2.49.0.1.840.0.d18090bb177374aea140021f70fc9d2f965646ee.001.1","noaa_urn:oid:2.49.0.1.840.0.1b917de414e3bf900da8f6a3e67cd524756d5dfc.001.1","noaa_urn:oid:2.49.0.1.840.0.d26df44dbbc5549fbf259cf33d49766c390625f9.001.1","noaa_urn:oid:2.49.0.1.840.0.82aa45509928d0214d73fe4bc1916b2aa010e8ab.002.1","noaa_urn:oid:2.49.0.1.840.0.615f50210e8597fa9f129ddd2bd3db9a5431c96a.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 48/100, near Linton Hall (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.