This alert expired on 23 June 2026 at 00:45 UTC. It is kept here as a record.
It is the 10th strongest of the 214 detections recorded within 20 km of this point since 16 March 2026. Another comparable one was recorded here earlier the same day. 11 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued June 22 at 6:56PM EDT until June 22 at 8:45PM EDT by NWS Baltimore MD/Washington DC
An estimated 2,514,526 people live within 50 km of this point.
Nearby, since 16 March 2026
- July 5, 2026 · score 52 · 4.2 km
- August 2, 2026 · score 66 · 4.6 km
- March 20, 2026 · score 52 · 7.1 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 82 % 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 | 82% |
| Coordinates | 38.7619, -76.5103 |
| Nearest City | Greater Upper Marlboro (22 km) |
| Population Exposed | 2.5M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-22T22:56:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.f8bb1b6262a2885603b3ecde78d816bb |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Chesapeake Bay from Pooles Island to Sandy Point MD; Chesapeake Bay from Sandy Point to North Beach MD; Chesapeake Bay from North Beach to Drum Point MD; Chester River to Queenstown MD; Eastern Bay; Choptank River to Cambridge MD and the Little Choptank River; Patuxent River to Broomes Island MD; Chesapeake Bay from Drum Point MD to Smith Point VA; Tidal Potomac from Indian Head to Cobb Island MD; Tidal Potomac from Cobb Island MD to Smith Point VA; Tangier Sound and the inland waters surrounding Bloodsworth Island; Tidal Potomac from Key Bridge to Indian Head MD and 3 more areas |
| Headline | Special Marine Warning issued June 22 at 6:56PM EDT until June 22 at 8:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-06-22T20:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 6 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.f8bb1b6262a2885603b3ecde78d816bb7579536e.001.1","noaa_urn:oid:2.49.0.1.840.0.0efb2a55fee3a9bbfb08cc1cde948479e9a002c9.001.1","noaa_urn:oid:2.49.0.1.840.0.1d75c56268f0a46186899fc0280dee0dce5c3339.001.1","noaa_urn:oid:2.49.0.1.840.0.dfa2d7f2783d7b2dac8484ac6b92e81b9cd0c0be.001.1","noaa_urn:oid:2.49.0.1.840.0.d29c492b045799f7d45c6d747d6ecb1d26ba5653.001.1","noaa_urn:oid:2.49.0.1.840.0.4c8a90525165bceacbb45604a1ae1020e841b815.001.1"] |
| Iem TypeSummary | D |
| Iem City | 2 WNW Burke |
| Iem County | Fairfax |
| Iem State | VA |
| Iem Wfo | LWX |
| Iem Remark | Numerous trees down in vicinity of Pond Spice Lane and Heron Pond Terrace. Siding and shingle damage as well. |
| MergedSources | [{"id":"iem_D_38.790_-77.300_1782162240000","source":"iem","severity":"low","severityValue":25,"timestamp":1782162240000,"latitude":38.79,"longitude":-77.3}] |
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 Greater Upper Marlboro?
Calamity.live data shows a weather event with CalamityScore 52/100, near Greater Upper Marlboro (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.