Severe Flood ● Closed
Flash Flood Warning issued September 17 at 8:39AM CDT until September 17 at 11:00AM CDT by NWS Chicago IL, United States of America
Loading live data… · Marker positions are approximate; severity is labelled in each popup. Sources: USGS, GDACS, NASA EONET, NOAA/NWS, EMSC.
At 839 AM CDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between 3
and 5.5 inches of rain have fallen. Flash flooding is already
occurring.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Rapid-onset flooding of creeks, streams, drainage ditches,
streets, underpasses, low-lying areas, and other poor
drainage areas.
Some locations that will experience flash flooding include...
Sandwich, Mendota, Amboy, Sheridan, Lake Holiday, Somonauk,
Earlville, Leland, Paw Paw, Sublette, Woodhaven Lakes, Millington,
Compton and West Brooklyn.
Measurements
| Coordinates | 41.6029, -89.1114 |
|---|---|
| Region | De Kalb, IL; La Salle, IL; Lee, IL |
| Location Precision | polygon |
| Issuing Authority | United States of America — us-noaa-nws-en |
| Cap Urgency | Immediate |
| Cap Certainty | Likely |
| Cap Expires | 2026-09-17T11:00:00-05:00 |
Official source
Warnings courtesy of the issuing national meteorological service, via the WMO Alert Hub.
This is an official warning issued by the authority named above. Follow its instructions and those of your local emergency services.
Severity as published by WMO Alert Hub (national weather services).
View original reportThis event as JSON · API and licence
Source updated 32 days ago (Sep 17, 2026 13:40 UTC) · we last heard from WMO Alert Hub (national weather services) 45 seconds ago
On a slow connection? Low-bandwidth version — no map, no scripts, under 14 KB.
Satellite view, before and after
The latest clear Sentinel-2 pass before this event and the earliest one after it.
11 Sep 2026, 6 days before this event. 1.1% cloud across the tile.
29 Sep 2026, 12 days after this event. 24.5% cloud across the tile.
The white ring marks where the event was reported.
Each image is a preview of a whole Sentinel-2 tile — an area of roughly 110 by 110 km, where one pixel is about 320 metres — not a close-up of the event, which may be a small part of it. "Clear" means under 30% cloud across the entire tile, so the exact place that matters can still be hidden. These are pictures for context, not an assessment of damage.
Contains modified Copernicus Sentinel data 2026, found through the Earth Search catalogue (Element 84) and served from the AWS Open Data Sentinel-2 archive.
Official authorities in United States
If you are there, these are the bodies whose instructions apply. This site is not an emergency service and does not issue warnings.
More for United States →What to do
Follow the instructions issued by WMO Alert Hub (national weather services) and your local emergency services. The guidance below is background.
Flood preparation, evacuation decisions, and the dangers of driving or walking through floodwater.
Open Flood Safety Guide →Earlier flood events in United States
Severe and extreme events of the same kind, before this one. Listed for scale, not because they are connected to it.
Nearby & related events
Disclaimer: figures are automatic feeds from the named agencies and may be revised. Do not use this page for life-safety decisions — follow official local emergency services.