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.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 21 September 2026 at 05:00 UTC. It is kept here as a record.
It is the 18th strongest of the 52 detections recorded within 20 km of this point since 14 April 2026. The last comparable one was on 19 September 2026. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flood Warning issued September 20 at 8:57AM CDT until September 21 at 1:30PM CDT by NWS La Crosse WI
Urban PEI: 58,799 within a heuristic 50 km radius; not unique people.
Nearby, since 14 April 2026
- September 5, 2026 · score 45 · 18.1 km
- August 11, 2026 · score 67 · 26.8 km
How we know
2 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 32 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) | 32 / 100 |
| Legacy data-support index | 0.86/1 |
| Coordinates | 42.5891, -91.1780 |
| Nearest City | Dubuque (44 km) |
| Urban exposure index (PEI) | 58.8K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-20T17:42:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.08cb5652b9428be8da847cd4cf2716bc934e3d49.001.1 |
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: 2026-09-20T17:42:00.000Z.
First archived: 2026-09-20T14:03:07.752Z. Material modification: not recorded.
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 | Flood Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Clayton, IA; Winneshiek, IA; Houston, MN and 13 more areas |
| Headline | Flood Warning issued September 20 at 8:57AM CDT until September 21 at 1:30PM CDT by NWS La Crosse WI |
| Expires | 2026-09-21T00:00:00-05:00 |
| SenderName | NWS La Crosse WI |
| HasExactCoords | true |
| MergedCount | 19 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.08cb5652b9428be8da847cd4cf2716bc934e3d49.001.1","noaa_urn:oid:2.49.0.1.840.0.08cb5652b9428be8da847cd4cf2716bc934e3d49.002.1","noaa_urn:oid:2.49.0.1.840.0.08cb5652b9428be8da847cd4cf2716bc934e3d49.003.1","noaa_urn:oid:2.49.0.1.840.0.848ef2a766d17b4e6332c37c585d7e85c8e85c67.001.1","noaa_urn:oid:2.49.0.1.840.0.75d81957bde3e2b7ef8068b6228b39897923f816.002.1","noaa_urn:oid:2.49.0.1.840.0.80434fdde08def1287091b05588e549f3b4a6b87.001.1","noaa_urn:oid:2.49.0.1.840.0.b35d3201bbd7bbfcb246b5ba67041bdaae5d063a.001.1","noaa_urn:oid:2.49.0.1.840.0.d52576a53463ec37e6a5567d2221f18ee2930910.001.1","noaa_urn:oid:2.49.0.1.840.0.f83734d54e93237ce49ffc2d1c093d04bc3de090.001.1","noaa_urn:oid:2.49.0.1.840.0.53e9e11973faa77b81ef27831e1e7b62c758cd3f.001.1","noaa_urn:oid:2.49.0.1.840.0.e7b4e6229bb22b5e91f8f60205d2e0d4f1c5bc57.002.1","noaa_urn:oid:2.49.0.1.840.0.e7b4e6229bb22b5e91f8f60205d2e0d4f1c5bc57.001.1","noaa_urn:oid:2.49.0.1.840.0.d3e46ce4fa7fbf4364510e436c6a75870de3a602.001.1","noaa_urn:oid:2.49.0.1.840.0.4e0ba0ffdd9c2c4b2ecfc5093c95deeddf10c60b.001.1","noaa_urn:oid:2.49.0.1.840.0.3d0fbcb045ac793c5109bbb95bdd0d1be0ee8af9.001.1","noaa_urn:oid:2.49.0.1.840.0.f4ccfa8873309fd3956392ef6fd903a4bf2a6994.001.1","noaa_urn:oid:2.49.0.1.840.0.591f25fbe25c9fcc3c1a9ffe9ee62f5fdcad40b6.001.1","noaa_urn:oid:2.49.0.1.840.0.c9ee179fe7eea40ca0b5ebfbe70617485e1247ea.001.1","noaa_urn:oid:2.49.0.1.840.0.c10ba31e9363469b68935b3938561fa711696fb9.001.1"] |
| Iem TypeSummary | F |
| Iem City | 1 NNE Monticello |
| Iem County | Jones |
| Iem State | IA |
| Iem Wfo | DVN |
| Iem Remark | Water over the road due to flash flooding. River Road is barricaded. |
| MergedSources | [{"id":"iem_F_42.250_-91.180_1789905600000","source":"iem","severity":"low","severityValue":25,"timestamp":1789905600000,"latitude":42.25,"longitude":-91.18}] |
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.
Want to know when something happens in this area?