Right now
The most recent data we hold from NOAA arrived 26 minutes 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 04:01 UTC. It is kept here as a record.
It is the 835th strongest of the 988 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: Severe Thunderstorm Warning issued September 3 at 11:51PM EDT until September 4 at 12:00AM EDT by NWS Baltimore MD/Washington DC
An estimated 4,969,323 people live within 50 km of this point.
Nearby, since 10 March 2026
- March 17, 2026 · score 52 · 7.0 km
- July 5, 2026 · score 52 · 8.0 km
- March 17, 2026 · score 52 · 8.0 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 46 out of 100, at 91 % 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 | 91% |
| Coordinates | 38.9831, -77.0941 |
| Nearest City | Bethesda (1 km) |
| Population Exposed | 5.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T03:51:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.1816d072d6ecd6602a11a0e9f2756bb784a4b37e.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Montgomery, MD; Fairfax, VA; Loudoun, VA; District of Columbia, DC; Montgomery, MD; Prince Georges, MD; Arlington, VA; Fairfax, VA; City of Alexandria, VA; City of Falls Church, VA |
| Headline | Severe Thunderstorm Warning issued September 3 at 11:51PM EDT until September 4 at 12:00AM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-09-04T00:01:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.1816d072d6ecd6602a11a0e9f2756bb784a4b37e.001.1","noaa_urn:oid:2.49.0.1.840.0.260665100174dae376a0e7925248211c7c6c24ca.001.1"] |
| Spc ReportType | wind |
| Spc Speed | UNK |
| Spc Location | Sterling Park |
| Spc County | Loudoun |
| Spc State | VA |
| Spc Comments | Tree & wires down along W Maple Avenue. Time estimated via radar. (LWX) |
| Google News RssFeed | weather |
| Google News SourceName | WBAL-TV |
| MergedSources | [{"id":"spc_wind_39.42_-77.42_239","source":"spc","severity":"medium","severityValue":45,"timestamp":1788488100000,"latitude":39.42,"longitude":-77.42},{"id":"spc_wind_39.34_-77.37_240","source":"spc","severity":"medium","severityValue":45,"timestamp":1788488700000,"latitude":39.34,"longitude":-77.37},{"id":"spc_wind_39.10_-77.74_243","source":"spc","severity":"medium","severityValue":45,"timestamp":1788490980000,"latitude":39.1,"longitude":-77.74},{"id":"spc_wind_39.00_-77.41_245","source":"spc","severity":"medium","severityValue":45,"timestamp":1788492180000,"latitude":39,"longitude":-77.41},{"id":"gnews_weather_496802_211","source":"google_news","severity":"medium","severityValue":40,"timestamp":1788489000000,"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.
Want to know when something happens near Bethesda?
Calamity.live data shows a weather event with CalamityScore 46/100, near Bethesda (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.