Right now
The most recent data we hold from NOAA arrived 11 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 3 July 2026 at 06:00 UTC. It is kept here as a record.
It is the 4th strongest of the 22 detections recorded within 20 km of this point since 14 April 2026. The last comparable one was on 10 June 2026.
What the source measured
NOAA reported: Flash Flood Warning issued July 2 at 6:58PM CDT until July 3 at 1:00AM CDT by NWS Des Moines IA
An estimated 137,335 people live within 50 km of this point.
Nearby, since 14 April 2026
- July 20, 2026 · score 67 · 16.1 km
How we know
Confirmed by 8 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 89 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 43 / 100 |
| Our confidence | 89% |
| Coordinates | 42.3092, -92.7767 |
| Nearest City | Marshalltown (31 km) |
| Population Exposed | 137.3K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-02T23:58:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.cb75368546da3357a7106491aff4df42a0332904.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Black Hawk, IA; Grundy, IA; Marshall, IA; Tama, IA |
| Headline | Flash Flood Warning issued July 2 at 6:58PM CDT until July 3 at 1:00AM CDT by NWS Des Moines IA |
| Expires | 2026-07-03T01:00:00-05:00 |
| SenderName | NWS Des Moines IA |
| HasExactCoords | true |
| Iem TypeSummary | R |
| Iem Magnitude | 3.99 |
| Iem Unit | Inch |
| Iem City | 1 SSE Reinbeck |
| Iem County | Grundy |
| Iem State | IA |
| Iem Wfo | DMX |
| Iem Remark | Storm total precipitation from a personal weather station. |
| MergedSources | [{"id":"iem_R_42.400_-92.450_1783040220000","source":"iem","severity":"low","severityValue":25,"timestamp":1783040220000,"latitude":42.4,"longitude":-92.45},{"id":"iem_R_42.360_-92.770_1783038180000","source":"iem","severity":"low","severityValue":25,"timestamp":1783038180000,"latitude":42.36,"longitude":-92.77},{"id":"iem_R_42.300_-92.780_1783040160000","source":"iem","severity":"low","severityValue":25,"timestamp":1783040160000,"latitude":42.3,"longitude":-92.78},{"id":"iem_F_42.340_-92.650_1783037940000","source":"iem","severity":"low","severityValue":25,"timestamp":1783037940000,"latitude":42.34,"longitude":-92.65},{"id":"iem_R_42.370_-92.670_1783040040000","source":"iem","severity":"low","severityValue":25,"timestamp":1783040040000,"latitude":42.37,"longitude":-92.67},{"id":"iem_R_42.260_-92.690_1783040100000","source":"iem","severity":"low","severityValue":25,"timestamp":1783040100000,"latitude":42.26,"longitude":-92.69},{"id":"iem_R_42.310_-92.590_1783040280000","source":"iem","severity":"low","severityValue":25,"timestamp":1783040280000,"latitude":42.31,"longitude":-92.59}] |
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 43/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.