Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 86, NWS Quad Cities, IA

August 12, 2021Van Buren County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 12, 2021, 7:26 AM CDT for Van Buren County, Iowa. It was in force for 33 min. 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
Aug 12, 2021, 7:26 AM CDT (12:26 UTC)
Expired
Aug 12, 2021, 7:59 AM CDT
In force
33 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Van Buren County, IA

The radar

The Quad Cities radar (KDVN), 152 km from the middle of the area, began a volume at 12:28 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

TimeReportWhereRemark
Aug 12, 7:50 AM CDTHAIL 1Farmington, IADELAYED REPORT. TIME ESTIMATED FROM RADAR.

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, 0.4 hours before the alert went out and 158 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2463 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

102 
WUUS53 KDVN 121226
SVRDVN
IAC177-121315-
/O.NEW.KDVN.SV.W.0086.210812T1226Z-210812T1315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
726 AM CDT Thu Aug 12 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Van Buren County in southeastern Iowa...

* Until 815 AM CDT.

* At 726 AM CDT, a severe thunderstorm was located over Keosauqua,
  moving east at 25 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will be near...
  Keosauqua around 735 AM CDT.

Other locations in the path of this severe thunderstorm include
Stockport, Bentonsport/Vernon and Bonaparte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4081 9218 4088 9174 4061 9172 4061 9176
      4060 9218
TIME...MOT...LOC 1226Z 262DEG 20KT 4074 9202 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

Ervin
6 follow-up statements
210 
WWUS53 KDVN 121233
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
733 AM CDT Thu Aug 12 2021

IAC177-121315-
/O.CON.KDVN.SV.W.0086.000000T0000Z-210812T1315Z/
Van Buren IA-
733 AM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 AM CDT
FOR VAN BUREN COUNTY...

At 733 AM CDT, a severe thunderstorm was located over Keosauqua,
moving east at 25 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
  Bentonsport/Vernon, Bonaparte and Stockport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4081 9218 4088 9174 4061 9172 4061 9176
      4060 9218
TIME...MOT...LOC 1233Z 262DEG 20KT 4075 9197 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Ervin
300 
WWUS53 KDVN 121241
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
741 AM CDT Thu Aug 12 2021

IAC177-121315-
/O.CON.KDVN.SV.W.0086.000000T0000Z-210812T1315Z/
Van Buren IA-
741 AM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 AM CDT
FOR VAN BUREN COUNTY...

At 741 AM CDT, a severe thunderstorm was located over Keosauqua,
moving east at 20 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
  Bentonsport/Vernon, Stockport and Bonaparte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4081 9218 4088 9174 4061 9172 4061 9176
      4060 9218
TIME...MOT...LOC 1241Z 267DEG 17KT 4073 9194 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Ervin
707 
WWUS53 KDVN 121244
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
744 AM CDT Thu Aug 12 2021

IAC177-121315-
/O.CON.KDVN.SV.W.0086.000000T0000Z-210812T1315Z/
Van Buren IA-
744 AM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 AM CDT
FOR EASTERN VAN BUREN COUNTY...

At 744 AM CDT, a severe thunderstorm was located over
Bentonsport/Vernon, or near Keosauqua, moving east at 25 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.

This severe storm will be near...
  Bonaparte around 755 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4084 9197 4088 9174 4061 9172 4061 9176
      4060 9207
TIME...MOT...LOC 1244Z 268DEG 20KT 4073 9189 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Ervin
754 
WWUS53 KDVN 121248
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
748 AM CDT Thu Aug 12 2021

IAC177-121315-
/O.CON.KDVN.SV.W.0086.000000T0000Z-210812T1315Z/
Van Buren IA-
748 AM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 AM CDT
FOR EASTERN VAN BUREN COUNTY...

At 747 AM CDT, a severe thunderstorm was located over
Bentonsport/Vernon, or near Keosauqua, moving east at 25 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.

This severe storm will be near...
  Bonaparte around 755 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4084 9197 4088 9174 4061 9172 4061 9176
      4060 9207
TIME...MOT...LOC 1247Z 271DEG 20KT 4072 9186 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Ervin
303 
WWUS53 KDVN 121256
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
756 AM CDT Thu Aug 12 2021

IAC177-121315-
/O.CON.KDVN.SV.W.0086.000000T0000Z-210812T1315Z/
Van Buren IA-
756 AM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 AM CDT
FOR EASTERN VAN BUREN COUNTY...

At 756 AM CDT, a severe thunderstorm was located over Bonaparte, or 8
miles east of Keosauqua, moving east at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

This severe thunderstorm will remain over mainly rural areas of
eastern Van Buren County, including the following locations...
Farmington, Indian Lake Park and Utica.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4085 9190 4088 9174 4061 9172 4061 9192
TIME...MOT...LOC 1256Z 271DEG 20KT 4072 9180 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Ervin
551 
WWUS53 KDVN 121259
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
759 AM CDT Thu Aug 12 2021

IAC177-121309-
/O.CAN.KDVN.SV.W.0086.000000T0000Z-210812T1315Z/
Van Buren IA-
759 AM CDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN VAN BUREN COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has weakened.
Therefore, the warning has been cancelled.  However gusty winds and 
heavy rain are still possible with this thunderstorm.

LAT...LON 4085 9190 4088 9174 4061 9172 4061 9192
TIME...MOT...LOC 1257Z 262DEG 20KT 4072 9177 

$$

Ervin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 2:09 AM CDTSpecial Weather StatementDVNLee21 min
Aug 12, 2:57 AM CDTHeat AdvisoryDVNLee8 hr
Aug 12, 7:24 AM CDTSpecial Weather StatementDVNVan Buren36 min
Aug 12, 9:10 AM CDTSpecial Weather StatementDVNVan Buren50 min
Aug 12, 9:23 AM CDTFlash Flood WarningDVNVan Buren4 hr
Aug 12, 9:54 AM CDTSpecial Weather StatementDVNLee, Van Buren96 min
Aug 12, 10:32 AM CDTFlash Flood WarningDVNLee, Van Buren6 hr
Aug 12, 11:29 AM CDTSpecial Weather StatementDVNLee, Van Buren91 min
Aug 12, 12:44 PM CDTFlash Flood WatchDVNDes Moines, Lee, Van Buren8 hr

Nearby

Severe Thunderstorm Warnings in Iowa, 2021Every 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.