Alert archive / Illinois / Flash Flood Warnings in 2017

Flash Flood Warning 8, NWS Quad Cities, IA

July 10, 2017Hancock County, Illinois

NWS Quad Cities, IA issued this flash flood warning at Jul 10, 2017, 8:41 PM CDT for Hancock County, Illinois. It was in force for 6 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: Jul 10, 2017, 8:41 PM CDT (01:41 UTC)
Expired: Jul 11, 2017, 2:45 AM 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), 136 km from the middle of the area, began a volume at 01:43 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 10, 9:09 PM CDT	FLASH FLOOD	5 Nne Keokuk, IL	6 INCHES OF WATER BLOCKING NORTHBOUND LANE OF TRAFFIC ON HIGHWAY 96. TRAFFIC WAS BEING DIVERTED INTO THE SOUTHBOUND LANE.

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 00:00Z, 1.7 hours before the alert went out and 140 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: 2871 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 1254 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 47 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

880 
WGUS53 KDVN 110141
FFWDVN
ILC067-110745-
/O.NEW.KDVN.FF.W.0008.170711T0141Z-170711T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Quad Cities IA/IL
841 PM CDT MON JUL 10 2017

The National Weather Service in the Quad Cities has issued a

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

* Until 245 AM CDT Tuesday

* At 841 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain have
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Nauvoo, Ferris, Colusa, Adrian, Niota, Nauvoo State Park and Camp
  Eastman.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4045 9138 4048 9137 4050 9136 4053 9138
      4054 9141 4055 9141 4060 9136 4061 9134
      4063 9129 4057 9115 4038 9116

$$

RP KINNEY

2 follow-up statements

268 
WGUS73 KDVN 110221
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
921 PM CDT MON JUL 10 2017

ILC067-110745-
/O.CON.KDVN.FF.W.0008.000000T0000Z-170711T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-
921 PM CDT MON JUL 10 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 AM CDT FOR
NORTHWESTERN HANCOCK COUNTY...

At 920 PM CDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to three inches of rain have already
fallen. Flash flooding is expected to begin shortly.

Some locations that will experience flooding include...
Nauvoo, Ferris, Colusa, Adrian, Niota, Nauvoo State Park and Camp
Eastman.

Additional rainfall amounts of 1 to 2 inches are possible in the 
southern part of the warned area...before the rain moves out by 11 
pm.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4045 9138 4048 9137 4050 9136 4053 9138
      4054 9141 4055 9141 4060 9136 4061 9134
      4063 9129 4057 9115 4038 9116

$$

RP KINNEY

608 
WGUS73 KDVN 110410
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
1110 PM CDT MON JUL 10 2017

ILC067-110418-
/O.CAN.KDVN.FF.W.0008.000000T0000Z-170711T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hancock IL-
1110 PM CDT MON JUL 10 2017

...THE FLASH FLOOD WARNING FOR NORTHWESTERN HANCOCK COUNTY IS
CANCELLED...

The heavy rain has ended. Additional flash flooding is no longer 
expected to pose a threat overnight. Law enforcement continues to 
divert traffic from the northbound lane of Highway 96 south of 
Nauvoo due to water on the road. Please continue to heed any 
remaining road closures.

LAT...LON 4045 9138 4048 9137 4050 9136 4053 9138
      4054 9141 4055 9141 4060 9136 4061 9134
      4063 9129 4057 9115 4038 9116

$$

RP KINNEY

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 10, 7:41 PM CDT	Special Weather Statement	DVN	Bureau, Putnam	64 min
Jul 10, 7:41 PM CDT	Tornado Warning	DVN	Hancock	34 min
Jul 10, 7:53 PM CDT	Special Weather Statement	DVN	McDonough	67 min
Jul 10, 8:10 PM CDT	Severe Thunderstorm Warning	DVN	McDonough	50 min
Jul 10, 8:17 PM CDT	Special Weather Statement	DVN	Hancock	58 min
Jul 10, 8:17 PM CDT	Tornado Warning	DVN	McDonough	28 min
Jul 10, 8:19 PM CDT	Flash Flood Warning	DVN	McDonough, Warren	6 hr
Jul 10, 9:03 PM CDT	Special Weather Statement	DVN	McDonough	57 min
Jul 10, 9:13 PM CDT	Special Weather Statement	DVN	Hancock	62 min
Jul 11, 6:26 AM CDT	Special Weather Statement	DVN	Hancock, Henderson, Mercer	49 min
Jul 11, 7:10 AM CDT	Special Weather Statement	DVN	Hancock, Henderson, McDonough, Mercer, Warren	50 min
Jul 11, 7:24 AM CDT	Special Weather Statement	DVN	Hancock	66 min
Jul 11, 8:15 AM CDT	Special Weather Statement	DVN	Putnam	45 min
Jul 11, 8:29 AM CDT	Severe Thunderstorm Warning	DVN	Bureau, Putnam	31 min
Jul 11, 11:25 AM CDT	Heat Advisory	DVN	Hancock, Henderson, McDonough, Mercer, Warren	9 hr

Nearby

Flash Flood Warnings in Illinois, 2017 Every flash flood warning in 2017

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.