Right now
The most recent data we hold from NOAA arrived 4 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 29 July 2026 at 03:15 UTC. It is kept here as a record.
It is the 77th strongest of the 148 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day. 4 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued July 28 at 7:11PM EDT until July 28 at 11:15PM EDT by NWS Mount Holly NJ
Urban PEI: 447,094 within a heuristic 50 km radius; not unique people.
Nearby, since 12 March 2026
- June 6, 2026 · score 48 · 6.2 km
- July 28, 2026 · score 37 · 11.7 km
- September 2, 2026 · score 41 · 12.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 37 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
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) | 37 / 100 |
| Legacy data-support index | 0.79/1 |
| Coordinates | 40.3731, -75.8419 |
| Nearest City | Reading (8 km) |
| Urban exposure index (PEI) | 447.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-28T23:11:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.b336775b3880be8ef12ec418d57b71b3 |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-07-28T23:11:00.000Z.
First archived: 2026-07-28T23:18:26.682Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | New Castle, DE; Camden, NJ; Gloucester, NJ; Salem, NJ; Delaware, PA; Philadelphia, PA; Bucks, PA; Lehigh, PA; Northampton, PA; Anne Arundel, MD; Baltimore, MD; Baltimore City, MD and 10 more areas |
| Headline | Flash Flood Warning issued July 28 at 7:11PM EDT until July 28 at 11:15PM EDT by NWS Mount Holly NJ |
| Expires | 2026-07-28T23:15:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 13 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.b336775b3880be8ef12ec418d57b71b31ebeed33.001.1","noaa_urn:oid:2.49.0.1.840.0.4a172a653778785ef8b7c48f4d43e13bb18d9a14.001.1","noaa_urn:oid:2.49.0.1.840.0.5a4a5bc677606f643de76c212a7ba0815efa191f.001.1","noaa_urn:oid:2.49.0.1.840.0.95c91f07c46f2da8281e587a7b514dc53f49a844.001.1","noaa_urn:oid:2.49.0.1.840.0.5b0d8ba7d2e304d69296571ed17cb38743e7f1d1.001.1","noaa_urn:oid:2.49.0.1.840.0.a6e86776984c5f74669b38fd73a042f559f0c82f.001.1","noaa_urn:oid:2.49.0.1.840.0.4e357847c713dc5ab4cc7e267e8d4f2f3a12e263.001.1","noaa_urn:oid:2.49.0.1.840.0.0e1a6469ce1fa548d33f34ab1f750acd87bb9573.001.1","noaa_urn:oid:2.49.0.1.840.0.22dc057b066f11c83d2f6a9a73df0a0efd2bbe6a.001.1","noaa_urn:oid:2.49.0.1.840.0.5cd333f6aa53845e788b72649023d4d9c77113f1.001.1","noaa_urn:oid:2.49.0.1.840.0.fe9231b1b337cf11b3671c465c45f39813a31eba.001.1","noaa_urn:oid:2.49.0.1.840.0.f3b97fe7b93a790e8263a204089ee5061c60f0b3.001.1","noaa_urn:oid:2.49.0.1.840.0.ed438f30656d9dcfdf4af08b09097679ad03df2b.001.1"] |
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 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.
Review the area, threshold and delivery channel in your account.
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