Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 84, NWS Quad Cities, IA

August 11, 2021Delaware County, Dubuque County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 11, 2021, 4:26 PM CDT for Delaware County, Dubuque County, Iowa. It was in force for 49 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: Aug 11, 2021, 4:26 PM CDT (21:26 UTC)
Expired: Aug 11, 2021, 5:15 PM CDT
In force: 49 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Delaware County, IA, Dubuque County, IA

The radar

The Quad Cities radar (KDVN), 106 km from the middle of the area, began a volume at 21:29 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 nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.4 hours before the alert went out and 109 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: 2852 J/kg
Mixed-layer CIN: -107 J/kg
Mixed-layer LCL: 1040 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 170 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.7

Open this sounding in Storm Lab

The text

As transmitted.

925 
WUUS53 KDVN 112126
SVRDVN
IAC055-061-112215-
/O.NEW.KDVN.SV.W.0084.210811T2126Z-210811T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
426 PM CDT Wed Aug 11 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Western Dubuque County in northeastern Iowa...
  Delaware County in northeastern Iowa...

* Until 515 PM CDT.

* At 425 PM CDT, a severe thunderstorm was located over Manchester,
  moving east at 30 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 thunderstorm will be near...
  Delaware around 430 PM CDT.
  Delhi, Greeley and Oneida around 435 PM CDT.
  Earlville around 440 PM CDT.

Other locations in the path of this severe thunderstorm include
Worthington, Dyersville, New Vienna, Farley, Luxemburg, Holy Cross,
Epworth and Bankston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4230 9094 4230 9160 4256 9156 4265 9106
      4265 9093
TIME...MOT...LOC 2125Z 262DEG 25KT 4247 9142 

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

$$

Ervin

4 follow-up statements

222 
WWUS53 KDVN 112137
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
437 PM CDT Wed Aug 11 2021

IAC055-061-112215-
/O.CON.KDVN.SV.W.0084.000000T0000Z-210811T2215Z/
Dubuque IA-Delaware IA-
437 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR WESTERN DUBUQUE AND DELAWARE COUNTIES...

At 437 PM CDT, a severe thunderstorm was located over Earlville, or 8
miles east of Manchester, moving east at 30 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.

Locations impacted include...
  Worthington, Dyersville, New Vienna, Farley, Epworth and Bankston.

LAT...LON 4230 9094 4230 9160 4245 9158 4265 9106
      4265 9093
TIME...MOT...LOC 2137Z 264DEG 25KT 4246 9129 

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

$$

Ervin

319 
WWUS53 KDVN 112146
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
446 PM CDT Wed Aug 11 2021

IAC055-061-112215-
/O.CON.KDVN.SV.W.0084.000000T0000Z-210811T2215Z/
Dubuque IA-Delaware IA-
446 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR WESTERN DUBUQUE AND DELAWARE COUNTIES...

At 446 PM CDT, a severe thunderstorm was located over Delhi, or 7
miles southeast of Manchester, 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.

Locations impacted include...
  Earlville, Hopkinton, Dyersville, Farley and Worthington.

LAT...LON 4230 9094 4230 9160 4245 9158 4265 9106
      4265 9093
TIME...MOT...LOC 2146Z 271DEG 20KT 4240 9135 

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

$$

Ervin

790 
WWUS53 KDVN 112154
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
454 PM CDT Wed Aug 11 2021

IAC055-061-112215-
/O.CON.KDVN.SV.W.0084.000000T0000Z-210811T2215Z/
Dubuque IA-Delaware IA-
454 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR SOUTHWESTERN DUBUQUE AND SOUTHEASTERN DELAWARE COUNTIES...

At 454 PM CDT, a severe thunderstorm was located over Delhi, or 10
miles southeast of Manchester, 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...
  Hopkinton around 500 PM CDT.

Other locations in the path of this severe thunderstorm include
Dyersville, Worthington, Cascade, Epworth and Farley.

LAT...LON 4230 9094 4230 9148 4243 9149 4256 9115
      4255 9094
TIME...MOT...LOC 2154Z 271DEG 20KT 4240 9129 

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

$$

Ervin

447 
WWUS53 KDVN 112203
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
503 PM CDT Wed Aug 11 2021

IAC055-061-112215-
/O.CON.KDVN.SV.W.0084.000000T0000Z-210811T2215Z/
Dubuque IA-Delaware IA-
503 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR SOUTHWESTERN DUBUQUE AND SOUTHEASTERN DELAWARE COUNTIES...

At 503 PM CDT, a severe thunderstorm was located near Hopkinton, or
13 miles southeast of Manchester, 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.

Locations impacted include...
  Dyersville, Worthington and Farley.

LAT...LON 4232 9102 4236 9140 4244 9134 4250 9115
      4248 9098
TIME...MOT...LOC 2203Z 271DEG 20KT 4240 9122 

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

$$

Ervin

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 5:38 AM CDT	Special Weather Statement	DVN	Lee	37 min
Aug 11, 5:56 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Lee	19 min
Aug 11, 6:10 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Lee	20 min
Aug 11, 6:24 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines	22 min
Aug 11, 6:38 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Louisa	37 min
Aug 11, 6:59 AM CDT	Flash Flood Warning	DVN	Des Moines, Lee	3 hr
Aug 11, 7:04 AM CDT	Special Weather Statement	DVN	Muscatine	26 min
Aug 11, 8:16 AM CDT	High Wind Warning	DVN	Clinton, Des Moines, Louisa, Muscatine, Scott	104 min
Aug 11, 9:46 AM CDT	Areal Flood Warning	DVN	Des Moines, Lee	3 hr
Aug 11, 10:24 AM CDT	Special Weather Statement	DVN	Lee	21 min
Aug 11, 3:36 PM CDT	Special Weather Statement	DVN	Washington	24 min
Aug 11, 5:11 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque, Jackson, Jones	49 min
Aug 11, 5:38 PM CDT	Tornado Warning	DVN	Dubuque	13 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.