This alert expired on 12 June 2026 at 23:30 UTC. It is kept here as a record.
It is the 21st strongest of the 160 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued June 12 at 5:29PM EDT until June 12 at 7:30PM EDT by NWS Baltimore MD/Washington DC
An estimated 593,308 people live within 50 km of this point.
Nearby, since 12 March 2026
- July 28, 2026 · score 43 · 5.5 km
- August 7, 2026 · score 37 · 9.9 km
- July 27, 2026 · score 52 · 10.2 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 48 out of 100, at 80 % 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) | 48 / 100 |
| Our confidence | 80% |
| Coordinates | 38.4677, -76.6767 |
| Nearest City | St. Charles (26 km) |
| Population Exposed | 593.3K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-12T21:29:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.25222f755a4881760eb4b6a83b30e050 |
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; Choptank River to Cambridge MD and the Little Choptank River |
| Headline | Special Marine Warning issued June 12 at 5:29PM EDT until June 12 at 7:30PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-06-12T19:30:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.25222f755a4881760eb4b6a83b30e050994faf3b.001.1","noaa_urn:oid:2.49.0.1.840.0.334ee04da0d55bfc151c8fca5ac35b18ed63004d.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 48/100, near St. Charles (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.