This alert expired on 28 August 2026 at 23:00 UTC. It is kept here as a record.
No stronger detection stands among the 74 recorded within 20 km of this point since 16 March 2026 — 12 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Flash Flood Warning issued August 28 at 2:58PM EDT until August 28 at 7:00PM EDT by NWS Mount Holly NJ
An estimated 223,327 people live within 50 km of this point.
Nearby, since 16 March 2026
- August 28, 2026 · score 43 · 1.4 km
- August 8, 2026 · score 37 · 3.2 km
- July 18, 2026 · score 43 · 4.5 km
How we know
Confirmed by 18 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 90 % 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) | 43 / 100 |
| Our confidence | 90% |
| Coordinates | 39.3651, -74.5692 |
| Nearest City | Pleasantville (5 km) |
| Population Exposed | 223.3K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-28T18:58:00.000Z |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Ocean, NJ; Sussex, DE; Atlantic, NJ and 1 more areas |
| Headline | Flash Flood Warning issued August 28 at 2:58PM EDT until August 28 at 7:00PM EDT by NWS Mount Holly NJ |
| Expires | 2026-08-28T19:00:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.ddc1c5f217f990760376b2db89870be2d5d1f3b4.001.1","noaa_urn:oid:2.49.0.1.840.0.0b759324fa4583dd2f5368c77d09c4ebf97a1a8d.001.1","noaa_urn:oid:2.49.0.1.840.0.5848cb40d5ae8e89a46645e22156d2d7631a0b2c.001.1","noaa_urn:oid:2.49.0.1.840.0.76f14ca80aa71c63edde37a9661e34bdff7a6503.001.1"] |
| Iem TypeSummary | R |
| Iem Magnitude | 1.34 |
| Iem Unit | Inch |
| Iem City | 1 NNE Holgate |
| Iem County | Ocean |
| Iem State | NJ |
| Iem Wfo | PHI |
| Iem Remark | Mesonet station EW4321 Beach Haven. |
| MergedSources | [{"id":"iem_R_39.190_-74.820_1787939700000","source":"iem","severity":"low","severityValue":25,"timestamp":1787939700000,"latitude":39.19,"longitude":-74.82},{"id":"iem_R_39.190_-74.820_1787937900000","source":"iem","severity":"low","severityValue":25,"timestamp":1787937900000,"latitude":39.19,"longitude":-74.82},{"id":"iem_R_39.140_-74.770_1787939700000","source":"iem","severity":"low","severityValue":25,"timestamp":1787939700000,"latitude":39.14,"longitude":-74.77},{"id":"iem_F_39.380_-74.560_1787935740000","source":"iem","severity":"low","severityValue":25,"timestamp":1787935740000,"latitude":39.38,"longitude":-74.56},{"id":"iem_R_39.520_-74.680_1787939820000","source":"iem","severity":"low","severityValue":25,"timestamp":1787939820000,"latitude":39.52,"longitude":-74.68},{"id":"iem_F_39.400_-74.550_1787938200000","source":"iem","severity":"low","severityValue":25,"timestamp":1787938200000,"latitude":39.4,"longitude":-74.55},{"id":"iem_R_39.380_-74.610_1787939400000","source":"iem","severity":"low","severityValue":25,"timestamp":1787939400000,"latitude":39.38,"longitude":-74.61},{"id":"iem_R_38.930_-74.960_1787938200000","source":"iem","severity":"low","severityValue":25,"timestamp":1787938200000,"latitude":38.93,"longitude":-74.96},{"id":"iem_R_39.370_-74.600_1787939100000","source":"iem","severity":"low","severityValue":25,"timestamp":1787939100000,"latitude":39.37,"longitude":-74.6},{"id":"iem_R_39.450_-74.730_1787938020000","source":"iem","severity":"low","severityValue":25,"timestamp":1787938020000,"latitude":39.45,"longitude":-74.73},{"id":"iem_R_39.140_-74.770_1787936100000","source":"iem","severity":"low","severityValue":25,"timestamp":1787936100000,"latitude":39.14,"longitude":-74.77},{"id":"iem_F_39.400_-74.560_1787938560000","source":"iem","severity":"low","severityValue":25,"timestamp":1787938560000,"latitude":39.4,"longitude":-74.56},{"id":"iem_R_38.930_-74.960_1787940000000","source":"iem","severity":"low","severityValue":25,"timestamp":1787940000000,"latitude":38.93,"longitude":-74.96},{"id":"iem_R_39.520_-74.680_1787937960000","source":"iem","severity":"low","severityValue":25,"timestamp":1787937960000,"latitude":39.52,"longitude":-74.68},{"id":"iem_R_39.370_-74.600_1787937300000","source":"iem","severity":"low","severityValue":25,"timestamp":1787937300000,"latitude":39.37,"longitude":-74.6},{"id":"iem_R_39.470_-74.450_1787938260000","source":"iem","severity":"low","severityValue":25,"timestamp":1787938260000,"latitude":39.47,"longitude":-74.45},{"id":"iem_R_39.540_-74.260_1787939760000","source":"iem","severity":"low","severityValue":25,"timestamp":1787939760000,"latitude":39.54,"longitude":-74.26}] |
Safety Information
During flooding: never walk, swim, or drive through floodwaters. Six inches of moving water can knock you down, and one foot of water can sweep away a vehicle. Move to higher ground if waters rise. After flooding, avoid contact with floodwater which may contain sewage, chemicals, or debris. Follow local emergency service guidance.
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 43/100, near Pleasantville (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 194 scientific monitoring sources.