Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 18, NWS Quad Cities, IA

June 20, 2021Benton County, Buchanan County, Linn County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Jun 20, 2021, 7:37 PM CDT for Benton County, Buchanan County, Linn County, Iowa. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jun 20, 2021, 7:37 PM CDT (00:37 UTC)
Expired: Jun 20, 2021, 8:15 PM CDT
In force: 38 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Benton County, IA, Buchanan County, IA, Linn County, IA

The radar

The Quad Cities radar (KDVN), 141 km from the middle of the area, began a volume at 00:38 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.

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

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.6 hours before the alert went out and 146 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.

092 
WUUS53 KDVN 210037
SVRDVN
IAC011-019-113-210115-
/O.NEW.KDVN.SV.W.0018.210621T0037Z-210621T0115Z/

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

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Buchanan County in northeastern Iowa...
  Northern Benton County in east central Iowa...
  Northwestern Linn County in east central Iowa...

* Until 815 PM CDT.

* At 736 PM CDT, severe thunderstorms were located along a line
  extending from near Independence to near Dysart, moving southeast
  at 35 mph.

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

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Independence around 740 PM CDT.
  Winthrop and Quasqueton around 750 PM CDT.
  Garrison and Mount Auburn around 800 PM CDT.
  Vinton around 805 PM CDT.

Other locations impacted by these severe thunderstorms include Lime
Creek County Park, Wapsipinicon Golf Course, Vinton Memorial Airport,
Rodgers Park, Benton City Park, Littleton, Hoefle-Dulin Park, Monti,
Buchanan County Fairgrounds and Otterville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4249 9161 4229 9160 4201 9201 4211 9230
      4230 9230 4230 9206 4247 9206 4247 9208
      4258 9208
TIME...MOT...LOC 0036Z 292DEG 29KT 4253 9184 4222 9237 

HAIL...0.75IN
WIND...60MPH
 
$$

RP Kinney

2 follow-up statements

212 
WWUS53 KDVN 210052
SVSDVN

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

IAC011-019-113-210115-
/O.CON.KDVN.SV.W.0018.000000T0000Z-210621T0115Z/
Buchanan IA-Benton IA-Linn IA-
752 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHERN BUCHANAN...NORTHERN BENTON AND NORTHWESTERN LINN
COUNTIES...

At 752 PM CDT, severe thunderstorms were located along a line
extending from Winthrop to near Dysart, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

These severe storms will be near...
  Winthrop and Quasqueton around 755 PM CDT.
  Mount Auburn around 800 PM CDT.
  Vinton around 810 PM CDT.

Other locations impacted by these severe thunderstorms include Lime
Creek County Park, Wapsipinicon Golf Course, Vinton Memorial Airport,
Rodgers Park, Benton City Park, Hoefle-Dulin Park, Monti, Buchanan
County Fairgrounds, Spencers Grove and Benton County Fairgrounds.

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 4249 9161 4229 9160 4201 9201 4211 9230
      4230 9230 4230 9206 4243 9206 4254 9186
TIME...MOT...LOC 0052Z 292DEG 29KT 4249 9170 4218 9223 

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

RP Kinney

784 
WWUS53 KDVN 210106
SVSDVN

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

IAC011-019-113-210115-
/O.CON.KDVN.SV.W.0018.000000T0000Z-210621T0115Z/
Buchanan IA-Benton IA-Linn IA-
806 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHERN BUCHANAN...NORTHERN BENTON AND NORTHWESTERN LINN
COUNTIES...

At 806 PM CDT, severe thunderstorms were located along a line
extending from near Masonville to near Garrison, moving east at 35
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

These severe thunderstorms will remain over mainly rural areas of
southern Buchanan, northern Benton and northwestern Linn Counties,
including the following locations... Lime Creek County Park, Monti,
Spencers Grove, Vinton Memorial Airport, Benton County Fairgrounds,
Minne Estema Park, Rodgers Park, Wildcat Bluff Park, Benton City Park
and Cheney.

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 4229 9160 4201 9201 4211 9230 4230 9230
      4230 9206 4234 9206 4241 9187 4240 9161
TIME...MOT...LOC 0106Z 292DEG 29KT 4245 9156 4214 9209 

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

RP Kinney

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, 7:48 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, 8:53 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jackson	67 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

Nearby

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.