Alert archive / Illinois / Flash Flood Warnings in 2018

Flash Flood Warning 9, NWS Quad Cities, IA

June 20, 2018Rock Island County, Illinois; Scott County, Iowa

NWS Quad Cities, IA issued this flash flood warning at Jun 20, 2018, 5:39 PM CDT for Rock Island County, Illinois; Scott County, Iowa. It was in force for 3 hr. 8 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: Jun 20, 2018, 5:39 PM CDT (22:39 UTC)
Expired: Jun 20, 2018, 8:45 PM CDT
In force: 3 hr
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Flood severity: None

Counties Scott County, IA, Rock Island County, IL

The radar

The Quad Cities radar (KDVN), 11 km from the middle of the area, began a volume at 22:38 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 20, 5:48 PM CDT	FLASH FLOOD	1 Wnw Davenport, IA	CARS STRANDED ON KIMBERLY RD WEST OF DIVISION TOWARDS WAL-MART, REPORT VIA KWQC FACEBOOK.
Jun 20, 5:50 PM CDT	FLASH FLOOD	1 Ne Davenport, IA	CAR STRANDED WITH WATER MORE THAN HALFWAY UP ITS SIDE. REPORT WITH PHOTO VIA KWQC FACEBOOK.
Jun 20, 5:54 PM CDT	FLASH FLOOD	2 Ese Davenport, IA	6+ INCHES FAST MOVING WATER NEAR INTERSECTION OF PERSHING AND DOVER. REPORT VIA FACEBOOK.
Jun 20, 6:15 PM CDT	HEAVY RAIN 2.93	Davenport Municipality, IA	TOTAL RAINFALL AS OF 615PM. RAIN STILL ONGOING.
Jun 20, 6:33 PM CDT	FLASH FLOOD	Bettendorf, IA	CAR STRANDED AT THE INTERSECTION OF TANGLEFOOT AND DEVILS GLEN RD IN BETTENDORF. REPORT W/ PHOTO VIA KWQC FACEBOOK PAGE.
Jun 20, 6:53 PM CDT	HEAVY RAIN 4	1 S Davenport, IA
Jun 20, 8:09 PM CDT	HEAVY RAIN 4.5	1 Ssw Davenport, IA	RAIN TOTAL SINCE 430 PM.
Jun 20, 8:24 PM CDT	HEAVY RAIN 2.53	1 Nw Eldridge, IA	RAINFALL IN PAST 12-HRS.

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, 10.7 hours before the alert went out and 11 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: 235 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 502 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 80 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

028 
WGUS53 KDVN 202239
FFWDVN
ILC161-IAC163-210045-
/O.NEW.KDVN.FF.W.0009.180620T2239Z-180621T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Quad Cities IA/IL
539 PM CDT WED JUN 20 2018

The National Weather Service in the Quad Cities has issued a

* Flash Flood Warning for...
  Central Rock Island County in northwestern Illinois...
  Scott County in east central Iowa...

* Until 745 PM CDT.

* At 538 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to 
  begin shortly. Estimated rainfall amounts of over 2 inches are 
  possible.

* Some locations that will experience flooding include...
  Davenport, Moline, Rock Island, Bettendorf, East Moline, Silvis,
  Eldridge, Le Claire, Hampton, Walcott, Blue Grass, Buffalo,
  Princeton, Long Grove, Riverdale, Donahue, McCausland, Carbon
  Cliff, Dixon and Maysville.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 285 and 306.
 Interstate 74 in Illinois between mile markers 1 and 2.
 Interstate 280 between mile markers 1 and 11.

LAT...LON 4150 9038 4144 9078 4177 9078 4176 9076
      4174 9075 4174 9072 4177 9067 4176 9065
      4176 9062 4177 9059 4176 9058 4177 9055
      4176 9043 4174 9043 4174 9041 4173 9041
      4174 9038 4173 9036 4174 9034

$$

16

3 follow-up statements

161 
WGUS73 KDVN 202330
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
630 PM CDT WED JUN 20 2018

ILC161-IAC163-210045-
/O.CON.KDVN.FF.W.0009.000000T0000Z-180621T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Rock Island IL-Scott IA-
630 PM CDT WED JUN 20 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR
CENTRAL ROCK ISLAND AND SCOTT COUNTIES...

At 625 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain are moving east of the warned area with minor additional 
rainfall amounts expected. Flash flooding is occurring in several 
locations over the past hour from rainfall of over locally over 2 
inches. Localized flash flooding will continue to be possible for 
the next hour before water levels recede.

Some locations that will experience flooding include...
Davenport, Moline, Rock Island, Bettendorf, East Moline, Silvis,
Eldridge, Le Claire, Hampton, Walcott, Blue Grass, Buffalo,
Princeton, Long Grove, Riverdale, Donahue, McCausland, Carbon Cliff,
Dixon and Maysville.

LAT...LON 4150 9038 4144 9078 4177 9078 4176 9076
      4174 9075 4174 9072 4177 9067 4176 9065
      4176 9062 4177 9059 4176 9058 4177 9055
      4176 9043 4174 9043 4174 9041 4173 9041
      4174 9038 4173 9036 4174 9034

$$

16

505 
WGUS53 KDVN 210034
FFWDVN
ILC161-IAC163-210145-
/O.EXT.KDVN.FF.W.0009.000000T0000Z-180621T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Quad Cities IA/IL
734 PM CDT WED JUN 20 2018

The National Weather Service in the Quad Cities has extended the

* Flash Flood Warning for...
  Central Rock Island County in northwestern Illinois...
  Scott County in east central Iowa...

* Until 845 PM CDT.

* At 731 PM CDT, emergency management reported some areas still 
  impacted by high water, most notably around Duck Creek. The flash 
  flood warning will be extended until 8:45 PM CDT due to locally 
  high water.

* Some locations that will experience flooding include...
  Davenport, Moline, Rock Island, Bettendorf, East Moline, Silvis,
  Eldridge, Le Claire, Hampton, Walcott, Blue Grass, Buffalo,
  Princeton, Long Grove, Riverdale, Donahue, McCausland, Carbon
  Cliff, Dixon and Maysville.

This includes the following highways... Interstate 74 in Iowa 
between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 285 and 306.
 Interstate 74 in Illinois between mile markers 1 and 2.
 Interstate 280 between mile markers 1 and 11.

LAT...LON 4150 9038 4144 9078 4177 9078 4176 9076
      4174 9075 4174 9072 4177 9067 4176 9065
      4176 9062 4177 9059 4176 9058 4177 9055
      4176 9043 4174 9043 4174 9041 4173 9041
      4174 9038 4173 9036 4174 9034

$$

16

266 
WGUS73 KDVN 210142
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
842 PM CDT WED JUN 20 2018

IAC163-ILC161-210150-
/O.EXP.KDVN.FF.W.0009.000000T0000Z-180621T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Rock Island IL-Scott IA-
842 PM CDT WED JUN 20 2018

...THE FLASH FLOOD WARNING FOR CENTRAL ROCK ISLAND AND SCOTT COUNTIES
WILL EXPIRE AT 845 PM CDT...

The heavy rain has ended with only additional light rain expected 
overnight. Flood waters have receded and Flooding is no longer 
expected to pose a threat. Please continue to heed any remaining 
road closures.

LAT...LON 4150 9038 4144 9078 4177 9078 4176 9076
      4174 9075 4174 9072 4177 9067 4176 9065
      4176 9062 4177 9059 4176 9058 4177 9055
      4176 9043 4174 9043 4174 9041 4173 9041
      4174 9038 4173 9036 4174 9034

$$

16

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 19, 8:51 PM CDT	River Flood Warning	DVN	Henry, Rock Island, Whiteside	14 days
Jun 20, 11:52 AM CDT	Special Weather Statement	DVN	Stephenson	3 hr
Jun 20, 4:35 PM CDT	Special Weather Statement	DVN	Henderson, Mercer, Warren	55 min
Jun 20, 4:47 PM CDT	Special Weather Statement	DVN	Hancock	58 min
Jun 20, 4:49 PM CDT	Special Weather Statement	DVN	Henry, Rock Island	56 min
Jun 19, 8:27 PM CDT	Special Weather Statement	DVN	Benton	63 min
Jun 20, 6:36 AM CDT	Special Weather Statement	DVN	Benton, Buchanan, Cedar, Iowa, Jefferson, Johnson and 4 more	24 min
Jun 20, 10:09 AM CDT	River Flood Watch	DVN	Iowa, Johnson	34 hr
Jun 20, 2:14 PM CDT	Special Weather Statement	DVN	Henry, Iowa, Jefferson, Keokuk, Lee, Van Buren and 1 more	61 min
Jun 20, 2:29 PM CDT	Tornado Warning	DVN	Keokuk	31 min
Jun 20, 3:10 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Johnson, Keokuk, Louisa, Washington	65 min
Jun 20, 3:29 PM CDT	Special Weather Statement	DVN	Benton	31 min
Jun 20, 4:33 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque, Jones, Linn	42 min
Jun 20, 5:25 PM CDT	Tornado Warning	DVN	Scott	29 min
Jun 20, 6:21 PM CDT	Special Weather Statement	DVN	Jefferson, Van Buren	54 min

Nearby

Flash Flood Warnings in Illinois, 2018 Flash Flood Warnings in Iowa, 2018 Every flash flood warning in 2018

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.