Right now
The most recent data we hold from NOAA arrived 6 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
6 other detections within 20 km in the last 24 hours, the nearest <1 km from here.
This alert expired on 15 September 2026 at 21:00 UTC. It is kept here as a record.
No stronger detection stands among the 25 recorded within 20 km of this point since 16 April 2026 — 3 others scored the same. The last comparable one was on 15 September 2026. 9 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flood Watch issued September 15 at 8:08AM CDT until September 15 at 4:00PM CDT by NWS Des Moines IA
Urban PEI: 18,990 within a heuristic 50 km radius; not unique people.
Nearby, since 16 April 2026
- September 9, 2026 · score 16 · 14.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 28 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) | 28 / 100 |
| Legacy data-support index | 0.82/1 |
| Coordinates | 41.4500, -94.3537 |
| Nearest City | Waukee (42 km) |
| Urban exposure index (PEI) | 19.0K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-16T01:34:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.5e70ba69a6ea831dac9f5e99a977f351f8920d0a.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: 2026-09-16T01:34:00.000Z.
First archived: 2026-09-15T13:14:05.381Z. Material modification: 2026-09-15T14:03:24.636Z.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
2026-09-15T14:03:24.636Z · data_change
Index 37 → 28; severity medium → medium; version 5 → 5.
Score Breakdown
Technical Details
| Event | Flood Watch |
| Urgency | Future |
| Certainty | Possible |
| AreaDesc | Cass; Polk |
| Headline | Flood Watch issued September 15 at 8:08AM CDT until September 15 at 4:00PM CDT by NWS Des Moines IA |
| Expires | 2026-09-15T16:00:00-05:00 |
| SenderName | NWS Des Moines IA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.5e70ba69a6ea831dac9f5e99a977f351f8920d0a.001.1","noaa_urn:oid:2.49.0.1.840.0.8ed0be51d780241cfdfff49af18c09db8aadabff.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.
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