This alert expired on 16 March 2026 at 16:45 UTC. It is kept here as a record.
It is the 7th strongest of the 144 detections recorded within 20 km of this point since 13 March 2026. Another comparable one was recorded here earlier the same day. 24 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued March 16 at 12:18PM EDT until March 16 at 12:45PM EDT by NWS Baltimore MD/Washington DC
An estimated 1,226,788 people live within 50 km of this point.
Nearby, since 13 March 2026
- March 17, 2026 · score 52 · 6.8 km
- May 19, 2026 · score 52 · 9.2 km
- September 3, 2026 · score 41 · 10.6 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 83 % 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 | 83% |
| Coordinates | 38.9508, -77.7183 |
| Nearest City | South Riding (19 km) |
| Population Exposed | 1.2M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-16T16:18:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.b512fb282dce1f04bf0a291ebe6b4519 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Culpeper, VA; Fauquier, VA; Orange, VA; Prince William, VA; Spotsylvania, VA; Stafford, VA; Amelia, VA; Cumberland, VA; Fluvanna, VA; Nottoway, VA; Powhatan, VA; Prince Edward, VA; Baltimore, MD; Carroll, MD; Howard, MD; Baltimore City, MD and 3 more areas |
| Headline | Severe Thunderstorm Warning issued March 16 at 12:18PM EDT until March 16 at 12:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-03-16T12:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 6 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.b512fb282dce1f04bf0a291ebe6b45193e0a4eda.001.1","noaa_urn:oid:2.49.0.1.840.0.8f1372c2952d5d1b9794971cd7f23b642eb8d7f2.001.1","noaa_urn:oid:2.49.0.1.840.0.34013a8715057b147811049f13ed431225159501.002.1","noaa_urn:oid:2.49.0.1.840.0.6c68f05943e6522b71afeb4215a8ae1cd5789a96.001.1","noaa_urn:oid:2.49.0.1.840.0.5a6ca9b32de7c7bfa3dba71fbdedfe262b9a3b96.001.1","noaa_urn:oid:2.49.0.1.840.0.b2dd7a316959422e76fc02a358fd3b41dc55d253.001.1"] |
| Iem TypeSummary | D |
| Iem City | Lisbon |
| Iem County | Howard |
| Iem State | MD |
| Iem Wfo | LWX |
| Iem Remark | Multiple small trees reported down in the median of I-70 near the Woodbine Road exit (exit 73). |
| MergedSources | [{"id":"iem_D_39.340_-77.070_1773677040000","source":"iem","severity":"low","severityValue":25,"timestamp":1773677040000,"latitude":39.34,"longitude":-77.07}] |
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 South Riding?
Calamity.live data shows a weather event with CalamityScore 52/100, near South Riding (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.