This alert expired on 12 March 2026 at 11:45 UTC. It is kept here as a record.
It is the 3rd strongest of the 138 detections recorded within 20 km of this point since 12 March 2026.
What the source measured
NOAA reported: Special Marine Warning issued March 12 at 6:11AM EDT until March 12 at 7:45AM EDT by NWS Baltimore MD/Washington DC
An estimated 137,507 people live within 50 km of this point.
Nearby, since 12 March 2026
- August 2, 2026 · score 28 · 3.9 km
- June 15, 2026 · score 22 · 7.5 km
- June 14, 2026 · score 22 · 8.3 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 78 % 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) | 43 / 100 |
| Our confidence | 78% |
| Coordinates | 38.3480, -76.4867 |
| Nearest City | St. Charles (48 km) |
| Population Exposed | 137.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-12T10:11:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special-Marine-Warning_noaa_urn-oid-2_49_0_1_840_0_53eee22e4fa9b8a7a4603885554c1ba0 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Tidal Potomac from Indian Head to Cobb Island MD; Tidal Potomac from Cobb Island MD to Smith Point VA; Chesapeake Bay from Sandy Point to North Beach MD; Chesapeake Bay from North Beach to Drum Point MD; Chesapeake Bay from Drum Point MD to Smith Point VA; Eastern Bay; 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 |
| Headline | Special Marine Warning issued March 12 at 6:11AM EDT until March 12 at 7:45AM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-03-12T07:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.53eee22e4fa9b8a7a4603885554c1ba0f93a8153.001.1","noaa_urn:oid:2.49.0.1.840.0.90a7b7dd5d72af827c8855a5aef11ae5c64cef84.001.1"] |
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 43/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.