Alert archive / Illinois / Flash Flood Warnings in 2021

Flash Flood Warning 8, NWS Quad Cities, IA

July 11, 2021Hancock County, Illinois

NWS Quad Cities, IA issued this flash flood warning at Jul 11, 2021, 11:54 AM CDT for Hancock County, Illinois. It was in force for 6 hr. 3 reports 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: Jul 11, 2021, 11:54 AM CDT (16:54 UTC)
Expired: Jul 11, 2021, 5:53 PM CDT
In force: 6 hr
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Flood severity: None

County Hancock County, IL

The radar

The Quad Cities radar (KDVN), 155 km from the middle of the area, began a volume at 16:58 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
Jul 11, 12:30 PM CDT	FLASH FLOOD	3 W Augusta, IL	SPOTTER REPORTED 6 INCHES OF WATER FLOWING OVER HIGHWAY. CAR STRANDED ON HIGHWAY AND DEPUTIES WERE IN THE PROCESS OF CLOSING IT.
Jul 11, 3:30 PM CDT	HEAVY RAIN 3.8	Augusta, IL	RAINFALL SINCE 530 AM. 5.60 INCHES SINCE YESTERDAY.
Jul 11, 3:37 PM CDT	HEAVY RAIN 2.9	1 S Denver, IL	RAINFALL TODAY.

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, 4.9 hours before the alert went out and 159 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: 10 J/kg
Mixed-layer CIN: -364 J/kg
Mixed-layer LCL: 532 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 60 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

574 
WGUS53 KDVN 111654
FFWDVN
ILC067-112300-
/O.NEW.KDVN.FF.W.0008.210711T1654Z-210711T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Quad Cities IA IL
1154 AM CDT Sun Jul 11 2021

The National Weather Service in Quad Cities has issued a

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

* Until 600 PM CDT Sunday.

* At 1154 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Radar indicates between 1 and 3 
  inches of rain have fallen. Additional rainfall amounts of 1 to 3 
  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...
  Keokuk, Hamilton, Warsaw, Augusta, Bowen, West Point, Plymouth, 
  Denver, Basco, Bentley, Stillwell, Sutter, Tioga and Hancock 
  County Fairgrounds.

This includes the following streams and drainages...
  Panther Creek, Bear Creek, Little Bear Creek, and Williams Creek. 
  Other small streams, creeks, and drainages can be impacted.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4040 9137 4035 9100 4028 9091 4020 9091
      4020 9151 4024 9151 4036 9145 4039 9138

FLASH FLOOD...RADAR INDICATED

$$

Gunkel

4 follow-up statements

434 
WGUS73 KDVN 111812
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
112 PM CDT Sun Jul 11 2021

ILC067-112300-
/O.CON.KDVN.FF.W.0008.000000T0000Z-210711T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-
112 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM CDT THIS EVENING 
FOR SOUTHERN HANCOCK COUNTY...

At 112 PM CDT, trained weather spotters reported thunderstorms 
producing heavy rain across the warned area, with 6 inches of water 
flowing over Highway 61 near Flour Creek between Bowen and Augusta 
Illinois. Also, cars were stranded on the highway and law 
enforcement is in the process of closing the road. Between 2 and 4 
inches of rain have fallen. Additional rainfall amounts of 1 to 2 
inches are possible in the warned area. Flash flooding is already 
occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

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...
  Keokuk, Hamilton, Warsaw, Augusta, Bowen, West Point, Plymouth, 
  Denver, Basco, Bentley, Stillwell, Sutter, Tioga and Hancock 
  County Fairgrounds.

This includes the following streams and drainages...
  Flour Creek, Panther Creek, Bear Creek, Little Bear Creek, and 
  Williams Creek. Other small streams, creeks, and drainages can be 
  impacted.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4040 9137 4035 9100 4028 9091 4020 9091
      4020 9151 4024 9151 4036 9145 4039 9138

FLASH FLOOD...OBSERVED

$$

Gunkel

181 
WGUS73 KDVN 111914
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
214 PM CDT Sun Jul 11 2021

ILC067-112300-
/O.CON.KDVN.FF.W.0008.000000T0000Z-210711T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-
214 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM CDT THIS EVENING 
FOR SOUTHERN HANCOCK COUNTY...

At 214 PM CDT, trained weather spotters reported thunderstorms 
producing heavy rain across the warned area, with water now 
surrounding homes in Augusta and water throughout many roads in 
town. Also, cars were stranded along Highway 61 and law enforcement 
has closed many roads and highways around and outside of town. 
Travel is not advised. Between 2 and 4 inches of rain have fallen. 
Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area. Flash flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

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...
  Keokuk, Hamilton, Warsaw, Augusta, Bowen, West Point, Plymouth, 
  Denver, Basco, Bentley, Stillwell, Sutter, Tioga and Hancock 
  County Fairgrounds.

This includes the following streams and drainages...
  Flour Creek, Panther Creek, Bear Creek, Little Bear Creek, and 
  Williams Creek. Other small streams, creeks, and drainages can be 
  impacted.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4040 9137 4035 9100 4028 9091 4020 9091
      4020 9151 4024 9151 4036 9145 4039 9138

FLASH FLOOD...OBSERVED

$$

Gunkel

814 
WGUS73 KDVN 112039
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
339 PM CDT Sun Jul 11 2021

ILC067-112300-
/O.CON.KDVN.FF.W.0008.000000T0000Z-210711T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-
339 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM CDT THIS EVENING 
FOR SOUTHERN HANCOCK COUNTY...

At 339 PM CDT, local law enforcement reported thunderstorms 
producing heavy rain across the warned area, where all roads in and 
out of Augusta are still not passable due to flash flooding. Between 
2 and 4 inches of rain have fallen. Additional rainfall amounts up 
to 1 inch are possible in the warned area. Flash flooding is already 
occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

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...
  Keokuk, Hamilton, Warsaw, Augusta, Bowen, West Point, Plymouth, 
  Denver, Basco, Bentley, Stillwell, Sutter, Tioga and Hancock 
  County Fairgrounds.

This includes the following streams and drainages...
  Flour Creek, Panther Creek, Bear Creek, Little Bear Creek, and 
  Williams Creek. Other small streams, creeks, and drainages can be 
  impacted.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4040 9137 4035 9100 4028 9091 4020 9091
      4020 9151 4024 9151 4036 9145 4039 9138

FLASH FLOOD...OBSERVED

$$

Gunkel

826 
WGUS73 KDVN 112253
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
553 PM CDT Sun Jul 11 2021

ILC067-112303-
/O.CAN.KDVN.FF.W.0008.000000T0000Z-210711T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-
553 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN HANCOCK COUNTY...

The heavy rain has ended. Please continue to heed remaining road 
closures. An areal flood warning will remain in effect for Southeast 
Hancock county through the night.

LAT...LON 4040 9137 4035 9100 4028 9091 4020 9091
      4020 9151 4024 9151 4036 9145 4039 9138

$$

Ervin

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 11:16 AM CDT	Special Weather Statement	DVN	Hancock	89 min
Jul 11, 12:31 PM CDT	Special Weather Statement	DVN	Hancock, McDonough	29 min
Jul 11, 2:35 PM CDT	Flash Flood Warning	DVN	Hancock, McDonough	3 hr
Jul 11, 5:49 PM CDT	Areal Flood Warning	DVN	Hancock, McDonough	18 hr

Nearby

Flash Flood Warnings in Illinois, 2021 Every flash flood warning in 2021

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.