This alert expired on 21 July 2026 at 20:30 UTC. It is kept here as a record.
It is the 11th strongest of the 36 detections recorded within 20 km of this point since 17 March 2026. The last comparable one was on 18 July 2026. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 21 at 4:12PM EDT until July 21 at 4:30PM EDT by NWS Mount Holly NJ
Nearby, since 17 March 2026
- May 21, 2026 · score 22 · 4.1 km
- May 19, 2026 · score 22 · 8.7 km
- May 21, 2026 · score 22 · 9.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 16 out of 100, at 59 % 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) | 16 / 100 |
| Our confidence | 59% |
| Coordinates | 39.2003, -79.4433 |
| Nearest City | Morgantown (65 km) |
| Impact Tier | minor |
| Timestamp | 2026-07-21T20:12:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.617c83a2fadd53f48b265a6c96ff9fbd |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Carbon, PA; Monroe, PA; Chester, PA; Delaware, PA; Fairfield, CT; Bronx, NY; Nassau, NY; Queens, NY; Suffolk, NY; Westchester, NY and 18 more areas |
| Headline | Severe Thunderstorm Warning issued July 21 at 4:12PM EDT until July 21 at 4:30PM EDT by NWS Mount Holly NJ |
| Expires | 2026-07-21T16:30:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 21 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.617c83a2fadd53f48b265a6c96ff9fbdd64716ec.001.1","noaa_urn:oid:2.49.0.1.840.0.b10c8201fbb17ec04a231be2b069b197ecaefab0.001.1","noaa_urn:oid:2.49.0.1.840.0.9c8537af120e6b0682cc050197b8ef0dff4fbd7f.001.1","noaa_urn:oid:2.49.0.1.840.0.a3d11dfaee8d4ac7c1cf0685301e8eaf60053ee2.001.1","noaa_urn:oid:2.49.0.1.840.0.a2824d2f61ecab06edb5dfe4ce6770d0c940f36d.001.1","noaa_urn:oid:2.49.0.1.840.0.0eec9792d2bca5594f87b2932211749d48399329.001.1","noaa_urn:oid:2.49.0.1.840.0.c3fbb97e6d3e57dd508cd5b70d4856745b28faaa.001.1","noaa_urn:oid:2.49.0.1.840.0.a0f20f12a24c6e67d7d403428f3692df38d9bcf4.002.1","noaa_urn:oid:2.49.0.1.840.0.3d24b1e718eb88cc17ba9eec9494d7d226507543.002.1","noaa_urn:oid:2.49.0.1.840.0.5a3b87cf1b4bab283df76633a5001c6a0ddee490.001.1","noaa_urn:oid:2.49.0.1.840.0.7fdb1afe90ec571ab0dd31ab36285c46b5c6be54.001.1","noaa_urn:oid:2.49.0.1.840.0.d1a217fe90416f944830df1e5eff9fef6a764226.001.1","noaa_urn:oid:2.49.0.1.840.0.e25b8082f8b7b057149a8287dbbf4595f4fd5651.001.1","noaa_urn:oid:2.49.0.1.840.0.e85768ee45ac2aad87f555d8b6fd750c3fe2593b.001.1","noaa_urn:oid:2.49.0.1.840.0.a528bb8aa682743448f1cdb1e275f43355285305.001.1","noaa_urn:oid:2.49.0.1.840.0.2b7c0af46ea6ba0b48f32c4766de7cce2cc8e717.001.1","noaa_urn:oid:2.49.0.1.840.0.77b4e3c37a7ab0eb80d8a104422de960243460f6.001.1","noaa_urn:oid:2.49.0.1.840.0.c988cb4a94fa40923df9889b9c710f0c1e0cc9a7.001.1","noaa_urn:oid:2.49.0.1.840.0.678b831dc0fba5e40ec3a447b129a261a66141d9.001.1","noaa_urn:oid:2.49.0.1.840.0.0d21f9707c16c94d08829fdcbcbec4ac68111e1d.001.1","noaa_urn:oid:2.49.0.1.840.0.efe94c82c09d5f488b26a42e0e29101a1f382cac.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 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.
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Calamity.live data shows a weather event with CalamityScore 16/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.