Right now
The most recent data we hold from NOAA arrived 9 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 19 September 2026 at 08:45 UTC. It is kept here as a record.
It is the 28th strongest of the 52 detections recorded within 20 km of this point since 15 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 September 19 at 2:20AM CDT until September 19 at 3:45AM CDT by NWS La Crosse WI
Urban PEI: 121,244 within a heuristic 50 km radius; not unique people.
Nearby, since 15 March 2026
- July 4, 2026 · score 43 · 6.1 km
- July 3, 2026 · score 43 · 7.0 km
- May 18, 2026 · score 43 · 24.5 km
How we know
2 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 | 0.86/1 |
| Coordinates | 43.5073, -91.5410 |
| Nearest City | La Crosse (41 km) |
| Urban exposure index (PEI) | 121.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-19T07:20:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.ef61c9f1195af79c888c6cd1b8d7d7250d2060d7.001.1 |
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: 2026-09-19T07:20:00.000Z.
First archived: 2026-09-19T07:23:36.961Z. Material modification: 2026-09-19T07:50:35.723Z.
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 | Fillmore, MN; Vernon, WI; Dane, WI and 1 more areas |
| Headline | Flash Flood Warning issued September 19 at 2:20AM CDT until September 19 at 3:45AM CDT by NWS La Crosse WI |
| Expires | 2026-09-19T03:45:00-05:00 |
| SenderName | NWS La Crosse WI |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.ef61c9f1195af79c888c6cd1b8d7d7250d2060d7.001.1","noaa_urn:oid:2.49.0.1.840.0.6def6730844f154ec5c6b78725485acf2db3e884.001.1","noaa_urn:oid:2.49.0.1.840.0.b462c1d4a9a3ed53cb92c0ae9dc8806008aed11a.001.1","noaa_urn:oid:2.49.0.1.840.0.dd1b220477d55a6174e58c65c830957b235c4f97.001.1"] |
| Iem TypeSummary | F |
| Iem City | 3 SSE Sheldon |
| Iem County | Houston |
| Iem State | MN |
| Iem Wfo | ARX |
| Iem Remark | Water about to cover entrance road. |
| MergedSources | [{"id":"iem_F_43.690_-91.540_1789795500000","source":"iem","severity":"low","severityValue":25,"timestamp":1789795500000,"latitude":43.69,"longitude":-91.54},{"id":"iem_F_43.650_-91.570_1789794060000","source":"iem","severity":"low","severityValue":25,"timestamp":1789794060000,"latitude":43.65,"longitude":-91.57}] |
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.
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