Severe weather near Greater Upper Marlboro
This alert expired on 12 June 2026 at 02:00 UTC. It is kept here as a record.
It is the 114th strongest of the 157 detections recorded within 20 km of this point since 16 March 2026. The last comparable one was on 11 June 2026. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued June 11 at 8:07PM EDT until June 11 at 10:00PM EDT by NWS Baltimore MD/Washington DC
An estimated 2,646,157 people live within 50 km of this point.
Nearby, since 16 March 2026
- July 18, 2026 · score 52 · 4.1 km
- March 20, 2026 · score 52 · 5.4 km
- March 17, 2026 · score 52 · 6.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 46 out of 100, at 79 % 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) | 46 / 100 |
| Our confidence | 79% |
| Coordinates | 38.6805, -76.6089 |
| Nearest City | Greater Upper Marlboro (21 km) |
| Population Exposed | 2.6M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-12T00:07:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.4a5c2109cd8a95f4960ff06b2ff8777c |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Chesapeake Bay from North Beach to Drum Point MD; 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; Chesapeake Bay from North Beach to Drum Point MD; Choptank River to Cambridge MD and the Little Choptank River; Patuxent River to Broomes Island MD; Tidal Potomac from Indian Head to Cobb Island MD and 2 more areas |
| Headline | Special Marine Warning issued June 11 at 8:07PM EDT until June 11 at 10:00PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-06-11T22:00:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.4a5c2109cd8a95f4960ff06b2ff8777cc23f3462.001.1","noaa_urn:oid:2.49.0.1.840.0.d99282cf24b30d86566742604a5dc1e7fa146ca4.001.1","noaa_urn:oid:2.49.0.1.840.0.99e74e3a566543097611c324122487ae2d2635d2.001.1","noaa_urn:oid:2.49.0.1.840.0.2fdaba90ad0a21fce5468b9b9b61daeb1a07e4cc.001.1","noaa_urn:oid:2.49.0.1.840.0.e78824aa55bf13f765fd7661a2df7fe224c27f2e.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 46/100, near Greater Upper Marlboro (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.