This alert expired on 6 August 2026 at 19:30 UTC. It is kept here as a record.
It is the 5th strongest of the 221 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 6 at 3:10PM EDT until August 6 at 3:30PM EDT by NWS Baltimore MD/Washington DC
An estimated 3,491,941 people live within 50 km of this point.
Nearby, since 12 March 2026
- March 16, 2026 · score 52 · 6.4 km
- March 17, 2026 · score 52 · 10.3 km
- March 17, 2026 · score 52 · 10.9 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 66 out of 100, at 85 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | critical |
| Calamity Score (ours) | 66 / 100 |
| Our confidence | 85% |
| Coordinates | 39.0780, -77.4880 |
| Nearest City | Ashburn (4 km) |
| Population Exposed | 3.5M within 50 km |
| Impact Tier | catastrophic |
| Timestamp | 2026-08-06T19:10:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.a562bf973c799c30d56ca39a7b303f520b519345.002.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Montgomery, MD; Loudoun, VA |
| Headline | Severe Thunderstorm Warning issued August 6 at 3:10PM EDT until August 6 at 3:30PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-08-06T15:30:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| Ogimet StationId | 72503 |
| Ogimet WindSpeed | 84 |
| Ogimet WindUnit | knots |
| Ogimet Temperature | 31.7 |
| Ogimet TemperatureUnit | C |
| Ogimet RawSynop | 08,06,17,51,AAXX 06184 72503 326// 62106 10317 20239 30176 40188 56010 91751 333 10322 20261 555 90618= |
| MergedSources | [{"id":"ogimet_72503_1786043305545","source":"ogimet","severity":"critical","severityValue":90,"timestamp":1786043305545,"latitude":38.9,"longitude":-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 66/100, near Ashburn (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.