This alert is in force until 4 September 2026, 07:00 UTC.
It is the 767th strongest of the 826 detections recorded within 20 km of this point since 10 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Flash Flood Warning issued September 4 at 12:24AM EDT until September 4 at 3:00AM EDT by NWS Baltimore MD/Washington DC
An estimated 4,254,677 people live within 50 km of this point.
Nearby, since 10 March 2026
- March 17, 2026 · score 52 · 0.6 km
- August 2, 2026 · score 66 · 1.6 km
- July 5, 2026 · score 52 · 4.7 km
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 46 out of 100, at 92 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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 |
| Our confidence | 92% |
| Coordinates | 38.8250, -77.1264 |
| Nearest City | Lincolnia (1 km) |
| Population Exposed | 4.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T04:24:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.5a1c8736e9128cb7b8a3751933d1bd9b95483170.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | District of Columbia, DC; Arlington, VA; Fairfax, VA; City of Alexandria, VA; City of Falls Church, VA |
| Headline | Flash Flood Warning issued September 4 at 12:24AM EDT until September 4 at 3:00AM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-09-04T03:00:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| Spc ReportType | wind |
| Spc Speed | 64 |
| Spc Location | Reagan National Arpt |
| Spc County | Arlington |
| Spc State | VA |
| Spc Comments | Measured wind gust of 64 mph at DCA. (LWX) |
| Iem TypeSummary | M |
| Iem Magnitude | 39 |
| Iem Unit | mph |
| Iem City | Reagan National Arpt |
| Iem County | Arlington |
| Iem State | VA |
Safety Information
During flooding: never walk, swim, or drive through floodwaters. Six inches of moving water can knock you down, and one foot of water can sweep away a vehicle. Move to higher ground if waters rise. After flooding, avoid contact with floodwater which may contain sewage, chemicals, or debris. Follow local emergency service guidance.
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 Lincolnia?
Calamity.live data shows a weather event with CalamityScore 46/100, near Lincolnia (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.