Alert archive / Illinois / Flash Flood Warnings in 2026

Flash Flood Warning 21, NWS Quad Cities, IA

June 11, 2026Hancock County, McDonough County, Illinois

NWS Quad Cities, IA issued this flash flood warning at Jun 11, 2026, 5:02 PM CDT for Hancock County, McDonough County, Illinois. It was in force for 4 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jun 11, 2026, 5:02 PM CDT (22:02 UTC)
Expired: Jun 11, 2026, 8:37 PM CDT
In force: 4 hr
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Flood severity: None

Counties Hancock County, IL, McDonough County, IL

The radar

The Quad Cities radar (KDVN), 144 km from the middle of the area, began a volume at 22:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Jun 11, 5:20 PM CDT	FLASH FLOOD	2 S Macomb, IL	Significant street flooding occurring.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.0 hours before the alert went out and 147 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 11 J/kg
Mixed-layer CIN: -285 J/kg
Mixed-layer LCL: 1008 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: -15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

511 
WGUS53 KDVN 112202
FFWDVN
ILC067-109-120415-
/O.NEW.KDVN.FF.W.0021.260611T2202Z-260612T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Quad Cities IA IL
502 PM CDT Thu Jun 11 2026

The National Weather Service in Quad Cities has issued a

* Flash Flood Warning for...
  Hancock County in west central Illinois...
  McDonough County in west central Illinois...

* Until 1115 PM CDT Thursday.

* At 502 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Macomb, Fort Madison, Keokuk, Carthage, Nauvoo, Bushnell, 
  Hamilton, Warsaw, Colchester, La Harpe, Dallas City, 
  Blandinsville, Augusta, Bowen, Industry, Good Hope, Prairie City, 
  Bardolph, West Point and Ferris.

This includes the following State Parks...
	Argyle Lake State Park and Nauvoo State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4019 9091 4020 9151 4024 9151 4034 9146
      4040 9137 4044 9138 4050 9136 4055 9141
      4061 9134 4064 9125 4063 9045 4028 9045
      4028 9091

FLASH FLOOD...RADAR INDICATED

$$

12

2 follow-up statements

247 
WGUS73 KDVN 112331
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
631 PM CDT Thu Jun 11 2026

ILC067-109-120415-
/O.CON.KDVN.FF.W.0021.000000T0000Z-260612T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-McDonough IL-
631 PM CDT Thu Jun 11 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT THIS 
EVENING FOR HANCOCK AND MCDONOUGH COUNTIES...

At 631 PM CDT, Heavy rainfall and run-off from the strong 
thunderstorms earlier may continue to produce lingering flooding 
over the next few hours. Plenty of street flooding was reported from 
the Macomb area.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Macomb, Fort Madison, Keokuk, Carthage, Nauvoo, Bushnell, 
  Hamilton, Warsaw, Colchester, La Harpe, Dallas City, 
  Blandinsville, Augusta, Bowen, Industry, Good Hope, Prairie City, 
  Bardolph, West Point and Ferris.

This includes the following State Parks...
	Argyle Lake State Park and Nauvoo State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4019 9091 4020 9151 4024 9151 4034 9146
      4040 9137 4044 9138 4050 9136 4055 9141
      4061 9134 4064 9125 4063 9045 4028 9045
      4028 9091

FLASH FLOOD...RADAR INDICATED

$$

12

675 
WGUS73 KDVN 120137
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
837 PM CDT Thu Jun 11 2026

ILC067-109-120147-
/O.CAN.KDVN.FF.W.0021.000000T0000Z-260612T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-McDonough IL-
837 PM CDT Thu Jun 11 2026

...FLASH FLOOD WARNING IS CANCELLED FOR HANCOCK AND MCDONOUGH 
COUNTIES...

The heavy rain has ended and flash flooding is no longer expected to 
pose a threat. Please continue to heed remaining road closures.

&&

LAT...LON 4044 9138 4050 9136 4055 9141 4061 9134
      4064 9125 4063 9045 4028 9045 4028 9091
      4019 9091 4020 9151 4024 9151 4034 9146
      4040 9137

$$

Uttech

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 10, 7:02 PM CDT	Tornado Warning	DVN	Bureau	43 min
Jun 10, 7:17 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, Henderson, McDonough, Warren	58 min
Jun 10, 7:20 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	Bureau, Henry, Putnam	55 min
Jun 10, 7:30 PM CDT	Severe Thunderstorm Warning	DVN	Hancock	75 min
Jun 10, 8:19 PM CDT	Flash Flood Warning	DVN	Hancock	5 hr
Jun 10, 8:49 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, McDonough, Warren	56 min
Jun 10, 9:26 PM CDT	Severe Thunderstorm Warning	DVN	Hancock	34 min
Jun 10, 9:44 PM CDT	River Flood Warning	DVN	Henry, Rock Island, Whiteside	5 days
Jun 10, 9:44 PM CDT	River Flood Warning	DVN	Henry, Rock Island	6 days
Jun 10, 10:13 PM CDT	River Flood Warning	DVN	Hancock, McDonough	3 days
Jun 11, 9:18 AM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	Mercer, Rock Island	52 min
Jun 11, 9:20 AM CDT	Severe Thunderstorm Warning	DVN	Henderson, Mercer, Warren	54 min
Jun 11, 9:36 AM CDT	River Flood Watch	DVN	Henry	11 hr
Jun 11, 11:21 AM CDT	Severe Thunderstorm Warning	DVN	Hancock, Henderson, McDonough, Warren	54 min
Jun 11, 3:09 PM CDT	Tornado Warning	DVN	Hancock	51 min
Jun 11, 3:51 PM CDT	Tornado Warning	DVN	Hancock	39 min
Jun 11, 4:19 PM CDT	Tornado Warning	DVN	Hancock, McDonough	56 min
Jun 11, 4:57 PM CDT	Flash Flood Warning	DVN	Jo Daviess, Stephenson	3 hr
Jun 11, 5:09 PM CDT	Tornado Warning	DVN	Putnam	17 min
Jun 11, 5:14 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, McDonough	45 min
Jun 11, 5:19 PM CDT	Tornado Warning	DVN	McDonough	41 min
Jun 11, 5:45 PM CDT	Tornado Warning	DVN	Bureau, Henry	30 min

Nearby

Flash Flood Warnings in Illinois, 2026 Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.