This alert expired on 6 August 2026 at 07:30 UTC. It is kept here as a record.
It is the 6th strongest of the 81 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day. 23 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued August 6 at 2:45AM EDT until August 6 at 3:30AM EDT by NWS Upton NY
An estimated 21,832,787 people live within 50 km of this point.
Nearby, since 12 March 2026
- June 12, 2026 · score 46 · 2.8 km
- July 28, 2026 · score 52 · 3.3 km
- August 6, 2026 · score 66 · 3.5 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 66 out of 100, at 91 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | critical |
| Calamity Score (ours) | 66 / 100 |
| Our confidence | 91% |
| Coordinates | 40.9208, -74.4195 |
| Nearest City | Denville (6 km) |
| Population Exposed | 21.8M within 50 km |
| Impact Tier | catastrophic |
| Timestamp | 2026-08-06T06:45:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.94900678c6fbe422b1bfddc4006dd0a4 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Bergen, NJ; Passaic, NJ; Rockland, NY; Morris, NJ; Hunterdon, NJ; Morris, NJ; Somerset, NJ |
| Headline | Flash Flood Warning issued August 6 at 2:45AM EDT until August 6 at 3:30AM EDT by NWS Upton NY |
| Expires | 2026-08-06T03:30:00-04:00 |
| SenderName | NWS Upton NY |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.94900678c6fbe422b1bfddc4006dd0a4217fe602.001.1","noaa_urn:oid:2.49.0.1.840.0.d4ffaa7ec1bd348c9ed7ba1f5b02619f7a3e435d.001.1","noaa_urn:oid:2.49.0.1.840.0.37a578abe7004d33dcc9dff5bbfb0c14c85f77f7.001.1"] |
| Iem TypeSummary | F |
| Iem City | 2 NNE Dover |
| Iem County | Morris |
| Iem State | NJ |
| Iem Wfo | PHI |
| Iem Remark | Flooding on I-80 Westbound At Exit 35 - Mount Hope Av (Rockaway Twp), All lanes closed. |
| Ogimet StationId | 72530 |
| Ogimet WindSpeed | 64 |
| Ogimet WindUnit | knots |
| Ogimet Temperature | 21.1 |
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 66/100, near Denville (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.