Right now
The most recent data we hold from NOAA arrived 18 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 May 2026 at 01:00 UTC. It is kept here as a record.
No stronger detection stands among the 65 recorded within 20 km of this point since 15 March 2026 — 37 others scored the same. Another comparable one was recorded here earlier the same day. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued May 18 at 3:19PM CDT until May 18 at 8:00PM CDT by NWS Springfield MO
An estimated 1,231,519 people live within 50 km of this point.
Nearby, since 15 March 2026
- May 18, 2026 · score 52 · 8.1 km
- July 11, 2026 · score 52 · 9.7 km
- July 5, 2026 · score 52 · 12.1 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 84 % 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) | 52 / 100 |
| Our confidence | 84% |
| Coordinates | 38.4871, -90.4787 |
| Nearest City | Arnold (11 km) |
| Population Exposed | 1.2M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T20:19:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.7a20f69a9e55d71d7a393b43d10d3641 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Benton, MO; Camden, MO; Hickory, MO; Miller, MO; Morgan, MO; Crawford, MO; Franklin, MO; Gasconade, MO; Warren, MO; Benton, MO; Hickory, MO; St. Clair, MO and 4 more areas |
| Headline | Flash Flood Warning issued May 18 at 3:19PM CDT until May 18 at 8:00PM CDT by NWS Springfield MO |
| Expires | 2026-05-18T20:00:00-05:00 |
| SenderName | NWS Springfield MO |
| HasExactCoords | true |
| MergedCount | 7 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.7a20f69a9e55d71d7a393b43d10d36416df44d41.001.1","noaa_urn:oid:2.49.0.1.840.0.f51d25858704af1517e0bba1e5bf5148f039ac5f.001.1","noaa_urn:oid:2.49.0.1.840.0.beb0d6cf72dd8898856703d54fc25b6c3cdbd28a.001.1","noaa_urn:oid:2.49.0.1.840.0.dbabff3a536120a3ca09dab0ff473b6cc62da205.002.1","noaa_urn:oid:2.49.0.1.840.0.913a8a86c94d4e638a15dcce4e3219a27fb4b386.001.1","noaa_urn:oid:2.49.0.1.840.0.981763280e670dafdad02306926ecdd4a788a568.001.1","noaa_urn:oid:2.49.0.1.840.0.acb5c63cf3a4cdea24b1f0e617f2449d79c4996e.001.1"] |
| Iem TypeSummary | H |
| Iem Magnitude | 0.7 |
| Iem Unit | Inch |
| Iem City | 1 NNE Oakville |
| Iem County | St. Louis |
| Iem State | MO |
| Iem Wfo | LSX |
| Iem Remark | NWS employee reported dime-size hail. |
| MergedSources | [{"id":"iem_H_38.460_-90.310_1779120300000","source":"iem","severity":"low","severityValue":25,"timestamp":1779120300000,"latitude":38.46,"longitude":-90.31}] |
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 near Arnold?
Calamity.live data shows a weather event with CalamityScore 52/100, near Arnold (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.