Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 22, NWS Quad Cities, IA

June 20, 2021Clinton County, Jackson County, Iowa; Carroll County, Jo Daviess County, Stephenson County, Illinois

NWS Quad Cities, IA issued this severe thunderstorm warning at Jun 20, 2021, 8:53 PM CDT for Clinton County, Jackson County, Iowa; Carroll County, Jo Daviess County, Stephenson County, Illinois. It was in force for 67 min. 4 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, 2021, 8:53 PM CDT (01:53 UTC)
Expired: Jun 20, 2021, 10:00 PM CDT
In force: 67 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Clinton County, IA, Jackson County, IA, Carroll County, IL, Jo Daviess County, IL, Stephenson County, IL

The radar

The Quad Cities radar (KDVN), 87 km from the middle of the area, began a volume at 01:54 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, 9:05 PM CDT	TSTM WND DMG	Savanna, IL	DOWNED TREE LIMB AND POWERLINE. TIME ESTIMATED FROM RADAR.
Jun 20, 9:08 PM CDT	HAIL 0.25	Lanark, IL	ALSO WIND GUST TO 45 MPH.
Jun 20, 9:10 PM CDT	TSTM WND DMG	Lanark, IL	7-8 INCH DIAMETER BRANCH DOWN FRANKLIN AND HIGH STREETS.
Jun 20, 9:13 PM CDT	HAIL 1.25	4 Sse Shannon, IL	MARBLE TO 1.25 INCH HAIL. LASTED 4 MINUTES.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 20, 4:01 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 20, 8:10 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.9 hours before the alert went out and 81 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: 1058 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 1009 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 174 m²/s²
0-3 km storm-relative helicity: 230 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 7.8

Open this sounding in Storm Lab

The text

As transmitted.

309 
WUUS53 KDVN 210153
SVRDVN
ILC015-085-177-IAC045-097-210300-
/O.NEW.KDVN.SV.W.0022.210621T0153Z-210621T0300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
853 PM CDT Sun Jun 20 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Southeastern Jo Daviess County in northwestern Illinois...
  Carroll County in northwestern Illinois...
  Southern Stephenson County in northwestern Illinois...
  Southeastern Jackson County in east central Iowa...
  Northeastern Clinton County in east central Iowa...

* Until 1000 PM CDT.

* At 853 PM CDT, severe thunderstorms were located along a line
  extending from near Elizabeth to Preston, moving east at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Woodbine around 900 PM CDT.
  Andover and Massbach around 905 PM CDT.
  Savanna and Sabula around 910 PM CDT.

Other locations in the path of these severe thunderstorms include
Pearl City, Argo Fay, Lanark, Fairhaven, Chadwick, Shannon and
Milledgeville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
sturdy building.

&&

LAT...LON 4220 8969 4193 8969 4193 8993 4199 9048
      4236 9027 4236 8940 4220 8940
TIME...MOT...LOC 0153Z 287DEG 28KT 4228 9023 4205 9037 

HAIL...<.75IN
WIND...60MPH
 
$$

Ervin

7 follow-up statements

410 
WWUS53 KDVN 210203
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
903 PM CDT Sun Jun 20 2021

ILC015-085-177-IAC045-097-210300-
/O.CON.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Jo Daviess IL-Carroll IL-Stephenson IL-Jackson IA-Clinton IA-
903 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR SOUTHEASTERN JO DAVIESS...CARROLL...SOUTHERN STEPHENSON...
SOUTHEASTERN JACKSON AND NORTHEASTERN CLINTON COUNTIES...

At 903 PM CDT, severe thunderstorms were located along a line
extending from near Massbach to Andover, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Stockton around 910 PM CDT.

Other locations in the path of these severe thunderstorms include
Argo Fay, Mount Carroll, Pearl City, Fairhaven, Shannon, Chadwick,
Freeport, Milledgeville, German Valley and Ridott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4220 8969 4193 8969 4193 8993 4199 9044
      4235 9018 4236 8940 4220 8940
TIME...MOT...LOC 0203Z 276DEG 35KT 4226 9008 4200 9026 

HAIL...<.75IN
WIND...60MPH
 
$$

Ervin

285 
WWUS53 KDVN 210209
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
909 PM CDT Sun Jun 20 2021

ILC015-085-177-IAC045-097-210300-
/O.CON.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Jo Daviess IL-Carroll IL-Stephenson IL-Jackson IA-Clinton IA-
909 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR SOUTHEASTERN JO DAVIESS...CARROLL...SOUTHERN STEPHENSON...
SOUTHEASTERN JACKSON AND NORTHEASTERN CLINTON COUNTIES...

At 909 PM CDT, severe thunderstorms were located along a line
extending from near Massbach to near Andover, moving east at 40 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

These severe storms will be near...
  Stockton around 915 PM CDT.

Other locations in the path of these severe thunderstorms include
Mount Carroll, Pearl City, Argo Fay, Fairhaven, Shannon, Chadwick,
Freeport, Milledgeville, German Valley and Ridott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4220 8969 4193 8969 4193 8993 4199 9044
      4235 9018 4236 8940 4220 8940
TIME...MOT...LOC 0209Z 276DEG 35KT 4226 9002 4199 9019 

HAIL...1.00IN
WIND...60MPH
 
$$

Ervin

207 
WWUS53 KDVN 210213
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
913 PM CDT Sun Jun 20 2021

ILC015-085-177-IAC045-097-210300-
/O.CON.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Jo Daviess IL-Carroll IL-Stephenson IL-Jackson IA-Clinton IA-
913 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR SOUTHEASTERN JO DAVIESS...CARROLL...SOUTHERN STEPHENSON...
SOUTHEASTERN JACKSON AND NORTHEASTERN CLINTON COUNTIES...

At 913 PM CDT, severe thunderstorms were located along a line
extending from 7 miles west of Pearl City to near Andover, moving
east at 40 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

These severe storms will be near...
  Mount Carroll and Pearl City around 925 PM CDT.

Other locations in the path of these severe thunderstorms include
Fairhaven, Shannon, Chadwick, Freeport, Milledgeville, German Valley
and Ridott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4220 8969 4193 8969 4193 8993 4199 9044
      4235 9004 4236 8940 4220 8940
TIME...MOT...LOC 0213Z 276DEG 35KT 4225 8996 4199 9014 

HAIL...1.00IN
WIND...60MPH
 
$$

Ervin

643 
WWUS53 KDVN 210221
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
921 PM CDT Sun Jun 20 2021

IAC097-210231-
/O.CAN.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Jackson IA-
921 PM CDT Sun Jun 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN JACKSON COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
east central Iowa. A Severe Thunderstorm Watch also remains in effect
until 100 AM CDT for northwestern Illinois.

LAT...LON 4220 8969 4193 8969 4193 8993 4198 9027
      4203 9021 4203 9016 4207 9017 4235 8984
      4236 8940 4220 8940
TIME...MOT...LOC 0221Z 275DEG 40KT 4224 8975 4198 9006 

$$

ILC015-085-177-IAC045-210300-
/O.CON.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Jo Daviess IL-Carroll IL-Stephenson IL-Clinton IA-
921 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR SOUTHEASTERN JO DAVIESS...CARROLL...SOUTHERN STEPHENSON AND
NORTHEASTERN CLINTON COUNTIES...

At 921 PM CDT, severe thunderstorms were located along a line
extending from near Pearl City to near Argo Fay, moving east at 45
mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

These severe storms will be near...
  Pearl City and Shannon around 925 PM CDT.
  Freeport around 930 PM CDT.

Other locations in the path of these severe thunderstorms include
Milledgeville, German Valley and Ridott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4220 8969 4193 8969 4193 8993 4198 9027
      4203 9021 4203 9016 4207 9017 4235 8984
      4236 8940 4220 8940
TIME...MOT...LOC 0221Z 275DEG 40KT 4224 8975 4198 9006 

HAIL...1.25IN
WIND...60MPH
 
$$

Ervin

993 
WWUS53 KDVN 210231
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
931 PM CDT Sun Jun 20 2021

ILC085-IAC045-210240-
/O.CAN.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Jo Daviess IL-Clinton IA-
931 PM CDT Sun Jun 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN JO DAVIESS AND
NORTHEASTERN CLINTON COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 100 AM CDT for
northwestern Illinois.

LAT...LON 4220 8969 4193 8969 4193 8993 4196 9013
      4207 9003 4213 8997 4224 8988 4235 8962
      4236 8940 4220 8940
TIME...MOT...LOC 0230Z 272DEG 38KT 4227 8955 4201 8986 

$$

ILC015-177-210300-
/O.CON.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Carroll IL-Stephenson IL-
931 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR CARROLL AND SOUTHERN STEPHENSON COUNTIES...

At 930 PM CDT, severe thunderstorms were located along a line
extending from near Ridott to Chadwick, moving east at 45 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

These severe storms will be near...
  Freeport, German Valley and Ridott around 935 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4220 8969 4193 8969 4193 8993 4196 9013
      4207 9003 4213 8997 4224 8988 4235 8962
      4236 8940 4220 8940
TIME...MOT...LOC 0230Z 272DEG 38KT 4227 8955 4201 8986 

HAIL...1.25IN
WIND...60MPH
 
$$

Ervin

963 
WWUS53 KDVN 210237
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
937 PM CDT Sun Jun 20 2021

ILC015-177-210300-
/O.CON.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Carroll IL-Stephenson IL-
937 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR EASTERN CARROLL AND SOUTHEASTERN STEPHENSON COUNTIES...

At 937 PM CDT, severe thunderstorms were located along a line
extending from near German Valley to Milledgeville, moving east at 35
mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

These severe storms will be near...
  German Valley and Ridott around 940 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4220 8969 4193 8969 4193 8993 4194 9000
      4203 8999 4210 8987 4230 8964 4234 8950
      4236 8940 4220 8940
TIME...MOT...LOC 0237Z 290DEG 32KT 4226 8949 4195 8975 

HAIL...1.25IN
WIND...60MPH
 
$$

Ervin

174 
WWUS53 KDVN 210250
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
950 PM CDT Sun Jun 20 2021

ILC015-177-210300-
/O.EXP.KDVN.SV.W.0022.000000T0000Z-210621T0300Z/
Carroll IL-Stephenson IL-
950 PM CDT Sun Jun 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN CARROLL AND
SOUTHEASTERN STEPHENSON COUNTIES WILL EXPIRE AT 1000 PM CDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.  However heavy rain is still possible with
these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 100 AM CDT for
northwestern Illinois.

LAT...LON 4220 8969 4193 8969 4193 8993 4194 9000
      4203 8999 4210 8987 4230 8964 4234 8950
      4236 8940 4220 8940
TIME...MOT...LOC 0250Z 287DEG 28KT 4223 8937 4192 8963 

$$

Ervin

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 7:08 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Keokuk	38 min
Jun 20, 7:08 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque, Jones, Linn	52 min
Jun 20, 7:37 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan, Linn	38 min
Jun 20, 7:48 PM CDT	Tornado Warning	DVN	Dubuque, Jackson, Jones	42 min
Jun 20, 8:04 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Lee, Van Buren	41 min
Jun 20, 8:18 PM CDT	Severe Thunderstorm Warning	DVN	Keokuk, Washington	42 min
Jun 20, 8:19 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jackson, Jones	41 min
Jun 20, 8:27 PM CDT	Tornado Warning Tornado observed	DVN	Jackson	33 min
Jun 20, 8:28 PM CDT	Tornado Warning	DVN	Keokuk, Washington	32 min
Jun 20, 8:37 PM CDT	Tornado Warning	DVN	Des Moines, Lee	39 min
Jun 20, 8:47 PM CDT	Special Weather Statement	DVN	Jones, Linn	43 min
Jun 20, 8:59 PM CDT	Special Weather Statement	DVN	Louisa	31 min
Jun 20, 9:29 PM CDT	Special Weather Statement	DVN	Lee	46 min
Jun 20, 9:36 PM CDT	Special Weather Statement	DVN	Scott	39 min
Jun 20, 9:18 PM CDT	Special Weather Statement	DVN	Henderson	42 min
Jun 20, 9:47 PM CDT	Special Weather Statement	DVN	Bureau, Henry	43 min
Jun 20, 10:03 PM CDT	Special Weather Statement	DVN	Hancock, McDonough	27 min
Jun 20, 10:23 PM CDT	Severe Thunderstorm Warning	DVN	McDonough	22 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2021 Severe Thunderstorm Warnings in Iowa, 2021 Every severe thunderstorm 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.