Right now
The most recent data we hold from NOAA arrived 10 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
5 other detections within 20 km in the last 24 hours, the nearest 2 km from here.
This alert expired on 17 September 2026 at 04:30 UTC. It is kept here as a record.
It is the 17th strongest of the 33 detections recorded within 20 km of this point since 23 March 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued September 16 at 9:25PM EDT until September 17 at 12:30AM EDT by NWS Cleveland OH
Urban PEI: 111,558 within a heuristic 50 km radius; not unique people.
Nearby, since 23 March 2026
- September 17, 2026 · score 37 · 1.7 km
- August 11, 2026 · score 43 · 10.6 km
- June 7, 2026 · score 43 · 17.4 km
How we know
3 recorded sources include NOAA; independence is not established by this count.
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 v5. 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 | 0.91/1 |
| Coordinates | 40.4283, -82.4883 |
| Nearest City | Mount Vernon (4 km) |
| Urban exposure index (PEI) | 111.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-17T01:25:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.3a7a8240f66a1b7288a279865cdc6580662b3635.001.1 |
Physical priority index · v5. 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: 2026-09-17T01:25:00.000Z.
First archived: 2026-09-17T01:30:42.903Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
2026-09-17T02:13:28.229Z · data_change
Index 37 → 37; severity medium → medium; version 5 → 5.
2026-09-17T02:08:08.788Z · data_change
Index 37 → 37; severity medium → medium; version 5 → 5.
2026-09-17T02:02:51.021Z · data_change
Index 37 → 37; severity medium → medium; version 5 → 5.
2026-09-17T01:57:31.737Z · data_change
Index 37 → 37; severity medium → medium; version 5 → 5.
2026-09-17T01:52:12.429Z · data_change
Index 37 → 37; severity medium → medium; version 5 → 5.
2026-09-17T01:46:50.949Z · data_change
Index 37 → 37; severity medium → medium; version 5 → 5.
2026-09-17T01:41:31.017Z · data_change
Index 37 → 37; severity medium → medium; version 5 → 5.
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Knox, OH |
| Headline | Flash Flood Warning issued September 16 at 9:25PM EDT until September 17 at 12:30AM EDT by NWS Cleveland OH |
| Expires | 2026-09-17T00:30:00-04:00 |
| SenderName | NWS Cleveland OH |
| HasExactCoords | true |
| Spc ReportType | wind |
| Spc Speed | UNK |
| Spc Location | 1 W Lucas |
| Spc County | Richland |
| Spc State | OH |
| Spc Comments | Multiple reports of trees and wires down southeast of Mansfield... OH. (CLE) |
| Iem TypeSummary | D |
| Iem City | 1 W Lucas |
| Iem County | Richland |
| Iem State | OH |
| Iem Wfo | CLE |
| Iem Remark | Multiple reports of trees and wires down southeast of Mansfield, OH. |
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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