Right now
The most recent data we hold from NOAA arrived 5 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
3 other detections within 20 km in the last 24 hours, the nearest 19 km from here.
This alert expired on 6 September 2026 at 23:00 UTC. It is kept here as a record.
It is the 9th strongest of the 24 detections recorded within 20 km of this point since 14 April 2026. The last comparable one was on 7 August 2026.
What the source measured
NOAA reported: Flash Flood Warning issued September 6 at 2:07PM CDT until September 6 at 6:00PM CDT by NWS Sioux Falls SD
Nearby, since 14 April 2026
- May 17, 2026 · score 46 · 12.7 km
- September 6, 2026 · score 16 · 19.0 km
- August 7, 2026 · score 22 · 19.9 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 16 out of 100, at 66 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 16 / 100 |
| Our confidence | 66% |
| Coordinates | 43.6439, -95.2952 |
| Nearest City | Sioux Falls (116 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-06T19:07:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.59962e180d6896f80d1c102e45bf7c19cb01611a.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Brookings, SD; Minnehaha, SD; Moody, SD; Emmet, IA; Palo Alto, IA; Lyon, IA; Osceola, IA; Nobles, MN and 1 more areas |
| Headline | Flash Flood Warning issued September 6 at 2:07PM CDT until September 6 at 6:00PM CDT by NWS Sioux Falls SD |
| Expires | 2026-09-06T18:00:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.59962e180d6896f80d1c102e45bf7c19cb01611a.001.1","noaa_urn:oid:2.49.0.1.840.0.e50ceaa837dc1c15ba5e009c50d224d4a557b915.001.1","noaa_urn:oid:2.49.0.1.840.0.032204aa5427611bd605212ae00ca34821ce295a.001.1","noaa_urn:oid:2.49.0.1.840.0.25a0a2eaaeea7d6fca7051e85db403216c6c6675.001.1"] |
| Iem TypeSummary | F |
| Iem City | 1 NNE Graettinger |
| Iem County | Palo Alto |
| Iem State | IA |
| Iem Wfo | DMX |
| Iem Remark | Significant ponding several feet deep with bundles of wood floating at EPS Buildings location on the north side of town. Water is also over the road on North Van Gordon Ave. |
| MergedSources | [{"id":"iem_F_43.240_-94.750_1788720900000","source":"iem","severity":"low","severityValue":25,"timestamp":1788720900000,"latitude":43.24,"longitude":-94.75}] |
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.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 16/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.