This alert expired on 27 June 2026 at 17:45 UTC. It is kept here as a record.
It is the 9th strongest of the 177 detections recorded within 20 km of this point since 11 March 2026. The last comparable one was on 15 June 2026. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued June 27 at 12:51PM EDT until June 27 at 1:45PM EDT by NWS Mount Holly NJ
An estimated 211,604 people live within 50 km of this point.
Nearby, since 11 March 2026
- July 27, 2026 · score 43 · 9.9 km
- March 17, 2026 · score 63 · 14.2 km
- August 3, 2026 · score 37 · 15.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 out of 100, at 80 % 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) | 43 / 100 |
| Our confidence | 80% |
| Coordinates | 39.1093, -75.3233 |
| Nearest City | Dover (18 km) |
| Population Exposed | 211.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-27T16:51:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.4fe039ffe16c57467ac4131f45ac4129 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Delaware Bay waters north of East Point NJ to Slaughter Beach DE; Delaware Bay waters south of East Point NJ to Slaughter Beach DE; Coastal waters from Cape May NJ to Cape Henlopen DE out 20 NM; Coastal waters from Cape Henlopen to Fenwick Island DE out 20 NM; Delaware Bay waters north of East Point NJ to Slaughter Beach DE |
| Headline | Special Marine Warning issued June 27 at 12:51PM EDT until June 27 at 1:45PM EDT by NWS Mount Holly NJ |
| Expires | 2026-06-27T13:45:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.4fe039ffe16c57467ac4131f45ac412997c7cb13.001.1","noaa_urn:oid:2.49.0.1.840.0.4cbb2fdc381f5f55d8bbb391fc3164d04d3a31ee.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 Dover?
Calamity.live data shows a weather event with CalamityScore 43/100, near Dover (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.