Right now
The most recent data we hold from NOAA arrived 14 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 00:00 UTC. It is kept here as a record.
It is the 6th strongest of the 46 detections recorded within 20 km of this point since 10 April 2026. Another comparable one was recorded here earlier the same day. 5 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 18 at 6:31PM CDT until May 18 at 7:00PM CDT by NWS Omaha/Valley NE
How we know
11 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 22 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 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) | 22 / 100 |
| Legacy data-support index | 0.70/1 |
| Coordinates | 39.6335, -96.6430 |
| Nearest City | Manhattan (51 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-05-18T23:31:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.473e4b410b7ac15509da89662799b15e |
Physical priority index · v1. 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: 2026-05-18T23:31:00.000Z.
First archived: 2026-05-18T23:32:56.444Z. 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 | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Fremont, IA; Mills, IA; Cass, NE; Nemaha, KS; Gage, NE; Lancaster, NE and 7 more areas |
| Headline | Severe Thunderstorm Warning issued May 18 at 6:31PM CDT until May 18 at 7:00PM CDT by NWS Omaha/Valley NE |
| Expires | 2026-05-18T19:00:00-05:00 |
| SenderName | NWS Omaha/Valley NE |
| HasExactCoords | true |
| MergedCount | 11 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.473e4b410b7ac15509da89662799b15e1181fc8a.002.1","noaa_urn:oid:2.49.0.1.840.0.acc9f6ef265192353fcbe3168197b306298168b7.001.1","noaa_urn:oid:2.49.0.1.840.0.557be8d57a11ceaefbc2369ff719004c56933774.001.1","noaa_urn:oid:2.49.0.1.840.0.67aa4129db657ef7053b0de139923cc912fd8dc0.001.1","noaa_urn:oid:2.49.0.1.840.0.3a4fb1cce01207707e5748b569602ec38fbc1a51.001.1","noaa_urn:oid:2.49.0.1.840.0.c61f90da2d5ace90c98f238cc72b510d579e215b.001.1","noaa_urn:oid:2.49.0.1.840.0.3c2c80064c785d3e5b95eb9725552e656ba10dce.001.1","noaa_urn:oid:2.49.0.1.840.0.5ebafb27cade4d8985a9cc7b7587f438025b7999.002.1","noaa_urn:oid:2.49.0.1.840.0.dcc9b23524b9edc987a6d5cbec2135bf52ad1849.001.1","noaa_urn:oid:2.49.0.1.840.0.faed7c00e92d7161f8fbe060444d7a17b0350ef0.001.1","noaa_urn:oid:2.49.0.1.840.0.1908c002b1c43fbe2aa9bf15fdf77a77abaff6c5.001.1"] |
| Iem TypeSummary | T |
| Iem City | 5 NNW Frankfort |
| Iem County | Marshall |
| Iem State | KS |
| Iem Wfo | TOP |
| Iem Remark | Storm chaser saw the tornado pass in front of them. They are seeing damage of grain bins in fields, power lines down and tree damage. |
| MergedSources | [{"id":"iem_T_39.600_-97.110_1779138180000","source":"iem","severity":"low","severityValue":25,"timestamp":1779138180000,"latitude":39.6,"longitude":-97.11},{"id":"iem_T_39.240_-97.020_1779143400000","source":"iem","severity":"low","severityValue":25,"timestamp":1779143400000,"latitude":39.24,"longitude":-97.02},{"id":"iem_T_39.640_-96.740_1779142500000","source":"iem","severity":"low","severityValue":25,"timestamp":1779142500000,"latitude":39.64,"longitude":-96.74},{"id":"iem_H_39.360_-97.430_1779137100000","source":"iem","severity":"low","severityValue":25,"timestamp":1779137100000,"latitude":39.36,"longitude":-97.43},{"id":"iem_H_39.470_-97.160_1779139680000","source":"iem","severity":"low","severityValue":25,"timestamp":1779139680000,"latitude":39.47,"longitude":-97.16},{"id":"iem_T_39.690_-96.640_1779143220000","source":"iem","severity":"low","severityValue":25,"timestamp":1779143220000,"latitude":39.69,"longitude":-96.64},{"id":"iem_T_39.610_-97.140_1779138240000","source":"iem","severity":"low","severityValue":25,"timestamp":1779138240000,"latitude":39.61,"longitude":-97.14},{"id":"iem_H_39.500_-97.130_1779139800000","source":"iem","severity":"low","severityValue":25,"timestamp":1779139800000,"latitude":39.5,"longitude":-97.13},{"id":"iem_T_39.340_-97.350_1779136200000","source":"iem","severity":"low","severityValue":25,"timestamp":1779136200000,"latitude":39.34,"longitude":-97.35},{"id":"iem_T_39.770_-96.460_1779144780000","source":"iem","severity":"low","severityValue":25,"timestamp":1779144780000,"latitude":39.77,"longitude":-96.46}] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
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.
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