Right now
The most recent data we hold from NOAA arrived 22 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
This alert expired on 5 July 2026 at 00:00 UTC. It is kept here as a record.
What the source measured
NOAA reported: Flash Flood Warning issued July 4 at 3:55PM CDT until July 4 at 7:00PM CDT by NWS Chicago IL
Urban PEI: 1,772,117 within a heuristic 50 km radius; not unique people.
How we know
4 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 52 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) | 52 / 100 |
| Legacy data-support index | 0.87/1 |
| Coordinates | 41.7325, -88.5372 |
| Nearest City | Yorkville (13 km) |
| Urban exposure index (PEI) | 1.8M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-04T20:55:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.f497232c1bfc5bd1e9846538a8f0614a |
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: 2026-07-04T20:55:00.000Z.
First archived: 2026-07-04T20:56:32.593Z. 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 | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Cook, IL; DuPage, IL; Kane, IL; Kane, IL; De Kalb, IL; La Salle, IL; Lee, IL and 3 more areas |
| Headline | Flash Flood Warning issued July 4 at 3:55PM CDT until July 4 at 7:00PM CDT by NWS Chicago IL |
| Expires | 2026-07-04T19:00:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| MergedCount | 7 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.f497232c1bfc5bd1e9846538a8f0614ab7cd1833.001.1","noaa_urn:oid:2.49.0.1.840.0.2a5bb9e40af7314ebb7eed7b262922d3824ef299.001.1","noaa_urn:oid:2.49.0.1.840.0.38d200f1522a22903e7b388791778b2b69df6d3b.001.1","noaa_urn:oid:2.49.0.1.840.0.859108eafbb84a988dec03d02ffccc13f2006925.001.1","noaa_urn:oid:2.49.0.1.840.0.4ea7509782665b41e73e1a6781706dc7ac2a512a.002.1","noaa_urn:oid:2.49.0.1.840.0.874b5c58f0768528ed8e3535851397f962ce32c9.001.1","noaa_urn:oid:2.49.0.1.840.0.bd4c19d57942e4538e6de434d674c9c183614cd0.001.1"] |
| Iem TypeSummary | F |
| Iem City | Spring Valley |
| Iem County | Bureau |
| Iem State | IL |
| Iem Wfo | DVN |
| Iem Remark | Multiple roads in Spring Valley closed due to water. |
| MergedSources | [{"id":"iem_R_41.570_-89.350_1783194240000","source":"iem","severity":"low","severityValue":25,"timestamp":1783194240000,"latitude":41.57,"longitude":-89.35},{"id":"iem_F_42.130_-88.520_1783193700000","source":"iem","severity":"low","severityValue":25,"timestamp":1783193700000,"latitude":42.13,"longitude":-88.52},{"id":"iem_F_41.330_-89.200_1783195080000","source":"iem","severity":"low","severityValue":25,"timestamp":1783195080000,"latitude":41.33,"longitude":-89.2}] |
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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