This alert expired on 4 September 2026 at 06:45 UTC. It is kept here as a record.
It is the 24th strongest of the 60 detections recorded within 20 km of this point since 17 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 4 at 1:22AM EDT until September 4 at 2:45AM EDT by NWS Mount Holly NJ
An estimated 32,899 people live within 50 km of this point.
Nearby, since 17 March 2026
- July 23, 2026 · score 34 · 6.1 km
- March 21, 2026 · score 34 · 7.2 km
- July 21, 2026 · score 28 · 12.7 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 28 out of 100, at 87 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 28 / 100 |
| Our confidence | 87% |
| Coordinates | 38.2216, -76.0449 |
| Nearest City | Salisbury (42 km) |
| Population Exposed | 32.9K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T05:22:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.4920b9e28b44c430595e68048998bfc165f959d0.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | 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; Waters from Cape May NJ to Fenwick Island DE from 20 to 60 NM; Tidal Potomac from Indian Head to Cobb Island MD; Tidal Potomac from Cobb Island MD to Smith Point VA; Chesapeake Bay from Smith Point to Windmill Point VA; Chesapeake Bay from Windmill Point to New Point Comfort VA; Rappahannock River from Urbanna to Windmill Point and 1 more areas |
| Headline | Special Marine Warning issued September 4 at 1:22AM EDT until September 4 at 2:45AM EDT by NWS Mount Holly NJ |
| Expires | 2026-09-04T02:45:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.4920b9e28b44c430595e68048998bfc165f959d0.001.1","noaa_urn:oid:2.49.0.1.840.0.8891b954f113ede98a8fefe1b5849a59db1a1584.001.1","noaa_urn:oid:2.49.0.1.840.0.6b42357ce5e01deeed4478f74533daa1088c3138.001.1","noaa_urn:oid:2.49.0.1.840.0.7fcc60d7a1ec10537cd7adf06ec6002be2c3fc49.001.1"] |
| Iem TypeSummary | M |
| Iem Magnitude | 47 |
| Iem Unit | mph |
| Iem City | 8 SSW Redgate |
| Iem County | ANZ537 |
| Iem State | MD |
| Iem Wfo | LWX |
| MergedSources | [{"id":"iem_M_38.260_-76.180_1788496380000","source":"iem","severity":"low","severityValue":25,"timestamp":1788496380000,"latitude":38.26,"longitude":-76.18},{"id":"iem_M_38.130_-76.530_1788494400000","source":"iem","severity":"low","severityValue":25,"timestamp":1788494400000,"latitude":38.13,"longitude":-76.53},{"id":"iem_M_38.040_-76.320_1788496380000","source":"iem","severity":"low","severityValue":25,"timestamp":1788496380000,"latitude":38.04,"longitude":-76.32},{"id":"iem_M_38.160_-76.670_1788495300000","source":"iem","severity":"low","severityValue":25,"timestamp":1788495300000,"latitude":38.16,"longitude":-76.67}] |
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 in this area?
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 185 scientific monitoring sources.