This alert expired on 12 March 2026 at 03:00 UTC. It is kept here as a record.
It is the 151st strongest of the 221 detections recorded within 20 km of this point since 11 March 2026.
What the source measured
NOAA reported: Severe Thunderstorm Watch issued March 11 at 7:03PM EDT until March 11 at 11:00PM EDT by NWS Mount Holly NJ
An estimated 39,403 people live within 50 km of this point.
Nearby, since 11 March 2026
- August 27, 2026 · score 34 · 0.0 km
- August 8, 2026 · score 34 · 0.0 km
- July 22, 2026 · score 46 · 0.0 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 34 out of 100, at 79 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 34 / 100 |
| Our confidence | 79% |
| Coordinates | 39.0000, -75.5000 |
| Nearest City | Dover (18 km) |
| Population Exposed | 39.4K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-11T23:03:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe-Thunderstorm-Watch_noaa_urn-oid-2_49_0_1_840_0_2674599bafdf5ac266db32865963be7d |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Watch |
| Urgency | Future |
| Certainty | Possible |
| AreaDesc | Kent, DE; New Castle, DE; Caroline, MD; Kent, MD; Queen Anne's, MD; Talbot, MD; Atlantic, NJ; Burlington, NJ; Camden, NJ; Cumberland, NJ; Gloucester, NJ; Mercer, NJ; Monmouth, NJ; Ocean, NJ; Salem, NJ; Berks, PA; Bucks, PA; Chester, PA; Delaware, PA; Lehigh, PA; Montgomery, PA; Philadelphia, PA; Delaware Bay waters north of East Point NJ to Slaughter Beach DE |
| Headline | Severe Thunderstorm Watch issued March 11 at 7:03PM EDT until March 11 at 11:00PM EDT by NWS Mount Holly NJ |
| Expires | 2026-03-11T23:00:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | false |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.2674599bafdf5ac266db32865963be7d22d0a117.001.1","noaa_urn:oid:2.49.0.1.840.0.2674599bafdf5ac266db32865963be7d22d0a117.002.1"] |
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 34/100, near Dover (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.