Flood Warning Issued for Hancock and McDonough Counties in Illinois

Source: NOAA · Western Illinois

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A Flood Warning has been issued by the National Weather Service for Hancock and McDonough counties in Illinois, forecasting minor flooding on the La Moine River from this evening until early Tuesday morning.

What this NWS weather alert tells you, and what most readers miss

This notice was issued by NOAA on April 28, 2026 and geographically references Western Illinois. Its severity classification of "high" signals how the issuing agency weighs the risk of harm if no action is taken - "critical" and "high" tier alerts typically carry direct consumer actions, while "medium" and "low" tend toward informational guidance or monitoring advisories. The category it belongs to - Weather Alerts - determines the warning protocol behind it, which shapes what protective action (seeking shelter, following evacuation orders if issued, monitoring official updates) is recommended and which agency holds authority to issue or cancel it.

Most readers skim a notice like this, check whether they are personally affected, and move on. The more useful lens is to read it as a data point about the issuing system: how quickly NOAA detected the hazard, how precise the geographic or product-identifier scope is, and whether similar notices have clustered in the same category or region in the last 90 days. Cluster patterns frequently precede a broader regulatory action, a single localized NWS weather alert is isolated; three of them within a quarter often indicate a supply-chain, infrastructure, or seasonal driver that will keep producing notices until something structural changes.

For decision-making, Areazine pairs each alert with the original agency URL, the full agency name, and a timestamp so you can verify the notice against the primary source before acting on it. Tags on this item (weather, alert, Flood Warning, Illinois) map to related alerts in the same area of risk - browsing them together gives a clearer picture than any single notice alone, because the shape of an ongoing issue only becomes visible across multiple sequential alerts.

Flood Warning in Illinois

Alert Details

A Flood Warning has been issued by the National Weather Service (NWS) Quad Cities IA IL. It is effective starting at 5:50 AM CDT on April 18, 2026.

Affected Areas

The warning affects Hancock and McDonough counties in Illinois, specifically the La Moine River at Colmar.

What You Should Do

Turn around and do not drown when encountering flooded roads. Do not attempt to drive around barricades or through flooded areas.

Expected Conditions

Minor flooding is forecast, with the river expected to rise above the 20.0-foot flood stage to a crest of 21.9 feet. At 20.0 feet, water will affect the lowest portions of Lambert Road and Lamar Road.

Timeline

The warning is effective from 5:50 AM CDT on April 18, 2026, with onset at 6:27 PM CDT on April 18, 2026. It expires at 6:00 AM CDT on April 19, 2026, and ends at 4:00 AM CDT on April 21, 2026.

Original source: NOAA Official Notice ↗

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Frequently Asked Questions

Common questions about this NWS weather alert.

What is this NWS weather alert about?
A Flood Warning has been issued by the National Weather Service for Hancock and McDonough counties in Illinois, forecasting minor flooding on the La Moine River from this evening until early Tuesday morning.
Which agency issued this alert?
This alert was issued by NOAA. The original notice is available at the source link at the bottom of this article.
How severe is this alert?
This alert is classified as "high" severity. Take precautions and monitor for updates.
What area is affected?
This alert affects Western Illinois. Check with NOAA for the most current geographic scope.
Where can I find more Weather Alerts updates?
Browse the full Weather Alerts feed on Areazine at areazine.com/weather/ for the latest updates from NOAA and other agencies.