Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 10, NWS Quad Cities, IA

June 18, 2021Louisa County, Washington County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Jun 18, 2021, 11:47 PM CDT for Louisa County, Washington County, Iowa. It was in force for 29 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: Jun 18, 2021, 11:47 PM CDT (04:47 UTC)
Expired: Jun 19, 2021, 12:16 AM CDT
In force: 29 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Louisa County, IA, Washington County, IA

The radar

The Quad Cities radar (KDVN), 82 km from the middle of the area, began a volume at 04:49 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 18, 11:52 PM CDT	HAIL 0.75	Washington, IA	RELAYED BY HAM RADIO OPERATOR.

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 18, 10:08 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.8 hours before the alert went out and 89 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: 4 J/kg
Mixed-layer CIN: -335 J/kg
Mixed-layer LCL: 2572 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: 55 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

981 
WUUS53 KDVN 190447
SVRDVN
IAC115-183-190530-
/O.NEW.KDVN.SV.W.0010.210619T0447Z-210619T0530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
1147 PM CDT Fri Jun 18 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Western Louisa County in southeastern Iowa...
  Southeastern Washington County in southeastern Iowa...

* Until 1230 AM CDT.

* At 1147 PM CDT, a severe thunderstorm was located over Washington,
  moving east at 35 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will be near...
  Ainsworth around 1155 PM CDT.
  Crawfordsville around 1200 AM CDT.
  Cotter and Wyman around 1205 AM CDT.

Other locations in the path of this severe thunderstorm include
Columbus Junction, Columbus City and Letts.

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 4138 9175 4137 9137 4134 9137 4133 9122
      4123 9117 4113 9131 4114 9137 4116 9137
      4116 9147 4122 9178
TIME...MOT...LOC 0447Z 279DEG 32KT 4129 9167 

HAIL...1.00IN
WIND...<50MPH
 
$$

Gibbs

3 follow-up statements

432 
WWUS53 KDVN 190457
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1157 PM CDT Fri Jun 18 2021

IAC115-183-190530-
/O.CON.KDVN.SV.W.0010.000000T0000Z-210619T0530Z/
Louisa IA-Washington IA-
1157 PM CDT Fri Jun 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR WESTERN LOUISA AND SOUTHEASTERN WASHINGTON COUNTIES...

At 1157 PM CDT, a severe thunderstorm was located over Ainsworth, or
7 miles east of Washington, moving east at 35 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

This severe storm will be near...
  Cotter and Wyman around 1205 AM CDT.

Other locations in the path of this severe thunderstorm include
Columbus Junction, Columbus City and Letts.

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 4137 9154 4137 9137 4134 9137 4133 9122
      4123 9117 4113 9131 4114 9137 4116 9137
      4116 9147 4122 9178 4129 9163
TIME...MOT...LOC 0457Z 279DEG 32KT 4128 9155 

HAIL...1.00IN
WIND...<50MPH
 
$$

Gibbs

738 
WWUS53 KDVN 190501
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1201 AM CDT Sat Jun 19 2021

IAC183-190511-
/O.CAN.KDVN.SV.W.0010.000000T0000Z-210619T0530Z/
Washington IA-
1201 AM CDT Sat Jun 19 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WASHINGTON COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 500 AM CDT for
southeastern and east central Iowa.

LAT...LON 4134 9140 4134 9133 4133 9122 4123 9117
      4113 9131 4114 9137 4116 9137 4116 9148
      4132 9149
TIME...MOT...LOC 0501Z 279DEG 32KT 4127 9150 

$$

IAC115-190530-
/O.CON.KDVN.SV.W.0010.000000T0000Z-210619T0530Z/
Louisa IA-
1201 AM CDT Sat Jun 19 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR SOUTHWESTERN LOUISA COUNTY...

At 1201 AM CDT, a severe thunderstorm was located over Cotter, or 7
miles west of Columbus Junction, moving east at 35 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

This severe storm will be near...
  Columbus Junction around 1210 AM CDT.
  Columbus City around 1215 AM CDT.

Other locations in the path of this severe thunderstorm include
Letts.

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 4134 9140 4134 9133 4133 9122 4123 9117
      4113 9131 4114 9137 4116 9137 4116 9148
      4132 9149
TIME...MOT...LOC 0501Z 279DEG 32KT 4127 9150 

HAIL...1.00IN
WIND...<50MPH
 
$$

Gibbs

192 
WWUS53 KDVN 190516
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1216 AM CDT Sat Jun 19 2021

IAC115-190526-
/O.CAN.KDVN.SV.W.0010.000000T0000Z-210619T0530Z/
Louisa IA-
1216 AM CDT Sat Jun 19 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN LOUISA COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However small hail and
heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 500 AM CDT for
southeastern and east central Iowa.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
the Quad Cities.

LAT...LON 4134 9140 4134 9133 4133 9122 4123 9117
      4113 9131 4114 9137 4116 9137 4116 9148
      4132 9149
TIME...MOT...LOC 0514Z 279DEG 32KT 4125 9132 

$$

Gibbs

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 18, 10:17 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Louisa, Washington	58 min
Jun 18, 11:03 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines	27 min
Jun 18, 11:21 PM CDT	Severe Thunderstorm Warning	DVN	Henry, Jefferson	39 min
Jun 18, 11:29 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Louisa	46 min
Jun 19, 12:02 AM CDT	Severe Thunderstorm Warning	DVN	Keokuk, Washington	43 min
Jun 19, 12:12 AM CDT	Severe Thunderstorm Warning	DVN	Jefferson, Keokuk, Van Buren, Washington	48 min
Jun 19, 12:27 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Louisa	27 min
Jun 19, 1:08 AM CDT	Severe Thunderstorm Warning	DVN	Lee, Van Buren	49 min
Jun 19, 1:28 AM CDT	Special Weather Statement	DVN	Louisa	2 hr
Jun 19, 2:01 AM CDT	Special Weather Statement	DVN	Lee, Van Buren	59 min
Jun 19, 4:33 AM CDT	Severe Thunderstorm Warning	DVN	Lee, Van Buren	57 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.