This alert expired on 28 May 2026 at 01:45 UTC. It is kept here as a record.
It is the 8th strongest of the 147 detections recorded within 20 km of this point since 12 March 2026. The last comparable one was on 20 May 2026. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 27 at 8:18PM EDT until May 27 at 9:45PM EDT by NWS Baltimore MD/Washington DC
An estimated 2,818,049 people live within 50 km of this point.
Nearby, since 12 March 2026
- June 22, 2026 · score 76 · 2.4 km
- June 12, 2026 · score 52 · 5.8 km
- July 18, 2026 · score 52 · 5.8 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 91 % 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 | 91% |
| Coordinates | 38.5225, -77.1670 |
| Nearest City | Cherry Hill (10 km) |
| Population Exposed | 2.8M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-28T00:18:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.7d6886c3257435d26fe5cae052b206c59f5a20a8.001.1 |
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 May 27 at 8:18PM EDT until May 27 at 9:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-05-27T21:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| Iem TypeSummary | D |
| Iem City | 1 NNE Ethel |
| Iem County | Richmond |
| Iem State | VA |
| Iem Wfo | AKQ |
| Iem Remark | Tree down on Kellys Lane in Richmond County. Time estimated from radar. |
| MergedSources | [{"id":"iem_D_38.010_-76.790_1779906240000","source":"iem","severity":"low","severityValue":25,"timestamp":1779906240000,"latitude":38.01,"longitude":-76.79},{"id":"iem_D_37.990_-76.640_1779906960000","source":"iem","severity":"low","severityValue":25,"timestamp":1779906960000,"latitude":37.99,"longitude":-76.64},{"id":"iem_D_38.030_-76.860_1779906000000","source":"iem","severity":"low","severityValue":25,"timestamp":1779906000000,"latitude":38.03,"longitude":-76.86},{"id":"iem_D_38.010_-76.770_1779906540000","source":"iem","severity":"low","severityValue":25,"timestamp":1779906540000,"latitude":38.01,"longitude":-76.77}] |
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 52/100, near Cherry Hill (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.