This alert expired on 6 August 2026 at 21:45 UTC. It is kept here as a record.
It is the 613th strongest of the 827 detections recorded within 20 km of this point since 10 March 2026. Another comparable one was recorded here earlier the same day. 207 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued August 6 at 5:03PM EDT until August 6 at 5:45PM EDT by NWS Baltimore MD/Washington DC
An estimated 5,402,870 people live within 50 km of this point.
Nearby, since 10 March 2026
- June 22, 2026 · score 66 · 2.6 km
- March 16, 2026 · score 52 · 4.1 km
- July 4, 2026 · score 52 · 4.7 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 90 % 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) | 52 / 100 |
| Our confidence | 90% |
| Coordinates | 38.9818, -76.8240 |
| Nearest City | Seabrook (3 km) |
| Population Exposed | 5.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-06T21:03:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.6a4d3a800ce3e1e893afc89f8ae1e28d |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Patapsco River including Baltimore Harbor; Tidal Potomac from Key Bridge to Indian Head MD |
| Headline | Special Marine Warning issued August 6 at 5:03PM EDT until August 6 at 5:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-08-06T17:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.6a4d3a800ce3e1e893afc89f8ae1e28de5eb74cf.001.1","noaa_urn:oid:2.49.0.1.840.0.8d59f3cccc7b7f354edd91c4daf958e2dfad9547.001.1"] |
| Iem TypeSummary | D |
| Iem City | 1 E Gleedsville |
| Iem County | Loudoun |
| Iem State | VA |
| Iem Wfo | LWX |
| Iem Remark | Tree down on Evergreen Mills Rd. near Red Cedar Dr. |
| MergedSources | [{"id":"iem_D_39.060_-77.540_1786043100000","source":"iem","severity":"low","severityValue":25,"timestamp":1786043100000,"latitude":39.06,"longitude":-77.54},{"id":"iem_D_39.050_-77.580_1786042320000","source":"iem","severity":"low","severityValue":25,"timestamp":1786042320000,"latitude":39.05,"longitude":-77.58}] |
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.
Want to know when something happens near Seabrook?
Calamity.live data shows a weather event with CalamityScore 52/100, near Seabrook (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.