Right now
The most recent data we hold from NOAA arrived 3 hours ago, and this point is in it.
One other detection within 20 km in the last 24 hours, <1 km from here.
This alert is in force until 27 September 2026, 20:15 UTC.
No stronger detection stands among the 23 recorded within 20 km of this point since 13 March 2026 — 22 others scored the same. The last comparable one was on 26 September 2026. 22 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flood Warning issued September 26 at 9:12PM CDT until October 1 at 7:00AM CDT by NWS Chicago IL
Urban PEI: 2,257,029 within a heuristic 50 km radius; not unique people.
Nearby, since 13 March 2026
- September 26, 2026 · score 46 · 0.0 km
- September 25, 2026 · score 46 · 0.0 km
- August 9, 2026 · 6.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 46 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) | 46 / 100 |
| Legacy data-support index | 0.82/1 |
| Coordinates | 42.3921, -87.9336 |
| Nearest City | Gurnee (4 km) |
| Urban exposure index (PEI) | 2.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-27T02:12:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.8142b6734fa1399e2866f4b56b499ee6c5ec159f.002.1 |
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: 2026-09-27T02:12:00.000Z.
First archived: 2026-09-27T02:16:25.264Z. Material modification: 2026-09-27T07:56:58.346Z.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
2026-09-27T07:56:58.346Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T07:46:16.372Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T07:24:55.313Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T07:14:15.997Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T06:26:19.028Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T05:59:44.827Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T05:06:32.636Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T03:20:10.701Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
2026-09-27T02:58:59.767Z · data_change
Index 46 → 46; severity medium → medium; version 5 → 5.
Score Breakdown
Technical Details
| Event | Flood Warning |
| MessageId | urn:oid:2.49.0.1.840.0.8142b6734fa1399e2866f4b56b499ee6c5ec159f.002.1 |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Lake, IL |
| Headline | Flood Warning issued September 26 at 9:12PM CDT until October 1 at 7:00AM CDT by NWS Chicago IL |
| Expires | 2026-09-27T15:15:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.2c71983bc69c0792c2e2b1d190550fcb3236095d.002.1","noaa_urn:oid:2.49.0.1.840.0.2c71983bc69c0792c2e2b1d190550fcb3236095d.001.1"] |
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.
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