This alert expired on 16 March 2026 at 16:45 UTC. It is kept here as a record.
It is the 7th strongest of the 206 detections recorded within 20 km of this point since 12 March 2026. The last comparable one was on 12 March 2026. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued March 16 at 11:17AM EDT until March 16 at 12:45PM EDT by NWS Baltimore MD/Washington DC
An estimated 3,755,066 people live within 50 km of this point.
Nearby, since 12 March 2026
- March 16, 2026 · score 52 · 0.0 km
- May 19, 2026 · score 52 · 0.3 km
- September 4, 2026 · score 46 · 0.4 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 52 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 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) | 52 / 100 |
| Our confidence | 87% |
| Coordinates | 38.6522, -77.1672 |
| Nearest City | Lorton (8 km) |
| Population Exposed | 3.8M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-16T15:17:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.593de8605628c3bf668e005a7d0f353e0d694a46.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Tidal Potomac from Key Bridge to Indian Head MD; Tidal Potomac from Indian Head to Cobb Island MD |
| Headline | Special Marine Warning issued March 16 at 11:17AM EDT until March 16 at 12:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-03-16T12:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| Google News RssFeed | weather |
| Google News SourceName | The Washington Post |
| MergedSources | [{"id":"gnews_weather_492686_125","source":"google_news","severity":"medium","severityValue":40,"timestamp":1773672660000,"latitude":38.9,"longitude":-77.04},{"id":"gnews_weather_492687_135","source":"google_news","severity":"medium","severityValue":40,"timestamp":1773673599000,"latitude":38.9,"longitude":-77.04}] |
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 Lorton?
Calamity.live data shows a weather event with CalamityScore 52/100, near Lorton (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.