This alert expired on 4 September 2026 at 05:45 UTC. It is kept here as a record.
It is the 76th strongest of the 126 detections recorded within 20 km of this point since 12 March 2026. The last comparable one was on 2 September 2026.
What the source measured
NOAA reported: Special Marine Warning issued September 4 at 12:18AM EDT until September 4 at 1:45AM EDT by NWS Baltimore MD/Washington DC
Nearby, since 12 March 2026
- September 4, 2026 · score 16 · 0.3 km
- June 15, 2026 · score 22 · 4.6 km
- March 12, 2026 · score 43 · 8.0 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 61 % 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) | 16 / 100 |
| Our confidence | 61% |
| Coordinates | 38.3369, -76.3959 |
| Nearest City | St. Charles (55 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-04T04:18:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.7fcc60d7a1ec10537cd7adf06ec6002be2c3fc49.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Chesapeake Bay from Drum Point MD to Smith Point VA; Tangier Sound and the inland waters surrounding Bloodsworth Island; Chesapeake Bay from North Beach to Drum Point MD; Chesapeake Bay from Drum Point MD to Smith Point VA; Choptank River to Cambridge MD and the Little Choptank River; Patuxent River to Broomes Island MD; Tangier Sound and the inland waters surrounding Bloodsworth Island; Chesapeake Bay from Pooles Island to Sandy Point MD; Chesapeake Bay from Sandy Point to North Beach MD; Chesapeake Bay from North Beach to Drum Point MD; Chester River to Queenstown MD; Eastern Bay; Choptank River to Cambridge MD and the Little Choptank River and 2 more areas |
| Headline | Special Marine Warning issued September 4 at 12:18AM EDT until September 4 at 1:45AM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-09-04T01:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.7fcc60d7a1ec10537cd7adf06ec6002be2c3fc49.001.1","noaa_urn:oid:2.49.0.1.840.0.bae28c608dc4b559fe09fb018021d1b94cb6e9c9.001.1","noaa_urn:oid:2.49.0.1.840.0.66b2b6d0a976dc6b0c24839ea420313b55fac435.001.1","noaa_urn:oid:2.49.0.1.840.0.1a818996a1faabaf502c7dec7e0e76060e564963.001.1","noaa_urn:oid:2.49.0.1.840.0.adb87b55b347a97fbbb4b6316068dcd8279ba985.001.1"] |
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 in this area?
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.