This alert expired on 10 August 2026 at 20:51 UTC. It is kept here as a record.
No stronger detection stands among the 73 recorded within 20 km of this point since 16 March 2026 — 32 others scored the same. Another comparable one was recorded here earlier the same day. 13 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 10 at 4:41PM EDT until August 10 at 4:45PM EDT by NWS Mount Holly NJ
An estimated 3,374,140 people live within 50 km of this point.
Nearby, since 16 March 2026
- March 16, 2026 · score 52 · 6.4 km
- July 7, 2026 · score 52 · 7.4 km
- March 17, 2026 · score 52 · 7.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 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) | 52 / 100 |
| Our confidence | 79% |
| Coordinates | 38.6897, -77.4443 |
| Nearest City | Buckhall (5 km) |
| Population Exposed | 3.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-10T20:41:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.549444d7620293fd3692f4a723ec8bab |
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 10 more areas |
| Headline | Severe Thunderstorm Warning issued August 10 at 4:41PM EDT until August 10 at 4:45PM EDT by NWS Mount Holly NJ |
| Expires | 2026-08-10T16:51:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 13 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.549444d7620293fd3692f4a723ec8baba85397ee.001.1","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:2.49.0.1.840.0.9773de75d375bf72c89e41b85cd0e11bf2c1edef.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:2.49.0.1.840.0.6dbf22d8674e2661728b4940bc2cb483c9d775cc.001.1","noaa_urn:oid:2.49.0.1.840.0.3f2344a37ce8fbaa03a78f9984fcc3843b044732.001.1","noaa_urn:oid:2.49.0.1.840.0.d09724ec2deafcfe21a1bc09e48a86c113a93dcb.002.1","noaa_urn:oid:2.49.0.1.840.0.f9c04b7cbadc6096a6b415304ca1291f76e91db5.002.1","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 52/100, near Buckhall (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.