This alert expired on 28 August 2026 at 00:00 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. The last comparable one was on 20 August 2026.
What the source measured
NOAA reported: Severe Thunderstorm Watch issued August 27 at 12:51PM EDT until August 27 at 8:00PM EDT by NWS Mount Holly NJ
An estimated 39,403 people live within 50 km of this point.
Nearby, since 11 March 2026
- August 8, 2026 · score 34 · 0.0 km
- July 22, 2026 · score 46 · 0.0 km
- July 21, 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 80 % 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 | 80% |
| Coordinates | 39.0000, -75.5000 |
| Nearest City | Dover (18 km) |
| Population Exposed | 39.4K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-27T16:51:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Watch_noaa_urn:oid:2.49.0.1.840.0.d463aa11c60a21073bb2899ac8f482b6 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Watch |
| Urgency | Future |
| Certainty | Possible |
| AreaDesc | Delaware Bay waters north of East Point NJ to Slaughter Beach DE; Delaware Bay waters south of East Point NJ to Slaughter Beach DE; Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 NM; Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 NM; Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 NM; Coastal waters from Great Egg Inlet to Cape May NJ out 20 NM; Kent, DE; New Castle, DE; Atlantic, NJ; Burlington, NJ; Camden, NJ; Cape May, NJ; Cumberland, NJ; Gloucester, NJ; Hunterdon, NJ; Mercer, NJ; Middlesex, NJ; Monmouth, NJ; Morris, NJ; Ocean, NJ; Salem, NJ; Somerset, NJ; Sussex, NJ; Warren, NJ; Bucks, PA; Chester, PA; Delaware, PA; Montgomery, PA; Philadelphia, PA |
| Headline | Severe Thunderstorm Watch issued August 27 at 12:51PM EDT until August 27 at 8:00PM EDT by NWS Mount Holly NJ |
| Expires | 2026-08-27T20:00:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | false |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.d463aa11c60a21073bb2899ac8f482b606222076.002.1","noaa_urn:oid:2.49.0.1.840.0.d463aa11c60a21073bb2899ac8f482b606222076.001.1"] |
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.