Severe Weather near Greater Upper Marlboro
Right now
The most recent data we hold from NOAA arrived 1 minute ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 4 September 2026 at 05:00 UTC. It is kept here as a record.
No stronger detection stands among the 57 recorded within 20 km of this point since 11 March 2026 — 29 others scored the same. The last comparable one was on 3 September 2026.
What the source measured
NOAA reported: Special Marine Warning issued September 3 at 10:54PM EDT until September 4 at 1:00AM EDT by NWS Baltimore MD/Washington DC
Urban PEI: 4,377,506 within a heuristic 50 km radius; not unique people.
Nearby, since 11 March 2026
- July 9, 2026 · 1.7 km
- June 22, 2026 · 6.1 km
- March 17, 2026 · 6.9 km
How we know
2 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 46 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 46 / 100 |
| Legacy data-support index | 0.87/1 |
| Coordinates | 38.8613, -76.7998 |
| Nearest City | Greater Upper Marlboro (6 km) |
| Urban exposure index (PEI) | 4.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T02:54:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.b1644aa1f74c835fb8a3aebbd9759aa4daae8b81.001.1 |
Physical priority index · v4 (historical). Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-09-04T02:54:00.000Z.
First archived: 2026-09-04T03:00:45.674Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
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; Tidal Potomac from Cobb Island MD to Smith Point VA; Patapsco River including Baltimore Harbor |
| Headline | Special Marine Warning issued September 3 at 10:54PM EDT until September 4 at 1:00AM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-09-04T01:00:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.b1644aa1f74c835fb8a3aebbd9759aa4daae8b81.001.1","noaa_urn:oid:2.49.0.1.840.0.37edd3b92fa852c058dc2f0701e63c81b7f410cf.001.1"] |
| Google News RssFeed | weather |
| Google News SourceName | WBAL-TV |
| MergedSources | [{"id":"gnews_weather_496802_214","source":"google_news","severity":"medium","severityValue":40,"timestamp":1788489311000,"latitude":39.29,"longitude":-76.61}] |
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.
Review the area, threshold and delivery channel in your account.
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