Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 91, NWS Quad Cities, IA

August 24, 2021Dubuque County, Jackson County, Iowa; Jo Daviess County, Stephenson County, Illinois

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 24, 2021, 4:17 PM CDT for Dubuque County, Jackson County, Iowa; Jo Daviess County, Stephenson County, Illinois. It was in force for 58 min. 5 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: Aug 24, 2021, 4:17 PM CDT (21:17 UTC)
Expired: Aug 24, 2021, 5:15 PM CDT
In force: 58 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Damage threat: Considerable
Hail: 1.0 in
Wind: 70.0 mph

Counties Dubuque County, IA, Jackson County, IA, Jo Daviess County, IL, Stephenson County, IL

The radar

The Quad Cities radar (KDVN), 97 km from the middle of the area, began a volume at 21:16 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
Aug 24, 4:25 PM CDT	TSTM WND GST 50	1 Se Asbury, IA	40 TO 50 MPH GUSTS ESTIMATED.
Aug 24, 4:33 PM CDT	HAIL 1	Dubuque Regional Arpt, IA	SOCIAL MEDIA REPORT WITH PICTURE.
Aug 24, 4:36 PM CDT	TSTM WND GST 60	Dubuque Regional Arpt, IA
Aug 24, 4:55 PM CDT	TSTM WND DMG	Bellevue, IA	SEVERAL 2+ INCH TREE LIMBS DOWN IN TOWN.
Aug 24, 4:58 PM CDT	TSTM WND DMG	Hanover, IL	LARGE TREES DOWN IN HANOVER. TIME ESTIMATED FROM RADAR.

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
Aug 24, 1:52 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.3 hours before the alert went out and 95 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: 1809 J/kg
Mixed-layer CIN: -127 J/kg
Mixed-layer LCL: 1284 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

653 
WUUS53 KDVN 242117
SVRDVN
ILC085-177-IAC061-097-242215-
/O.NEW.KDVN.SV.W.0091.210824T2117Z-210824T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
417 PM CDT Tue Aug 24 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Jo Daviess County in northwestern Illinois...
  Western Stephenson County in northwestern Illinois...
  Northwestern Jackson County in east central Iowa...
  Eastern Dubuque County in northeastern Iowa...

* Until 515 PM CDT.

* At 417 PM CDT, severe thunderstorms were located along a line
  extending from near Sherrill to near Bernard, moving east at 40
  mph.

  HAZARD...70 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Severe thunderstorms will be near...
  Sageville around 420 PM CDT.
  Zwingle around 425 PM CDT.
  La Motte around 430 PM CDT.
  St. Donatus around 435 PM CDT.

Other locations in the path of these severe thunderstorms include
Bellevue, Hanover, Elizabeth, Woodbine and Massbach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4263 9070 4251 9064 4250 8974 4220 8983
      4220 9075 4265 9079
TIME...MOT...LOC 2117Z 271DEG 37KT 4264 9070 4229 9078 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Ervin

3 follow-up statements

175 
WWUS53 KDVN 242143
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
443 PM CDT Tue Aug 24 2021

ILC085-177-IAC061-097-242215-
/O.CON.KDVN.SV.W.0091.000000T0000Z-210824T2215Z/
Jo Daviess IL-Stephenson IL-Jackson IA-Dubuque IA-
443 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR JO DAVIESS...WESTERN STEPHENSON...NORTHWESTERN JACKSON AND
EASTERN DUBUQUE COUNTIES...

At 443 PM CDT, severe thunderstorms were located along a line
extending from near Menominee to near Bellevue, moving east at 50
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...
  Hanover, Scales Mound, Schapville, Woodbine, Apple River, 
  Massbach, Warren, Stockton, Nora, Pearl City, Lena and Winslow.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4263 9070 4251 9064 4250 8974 4220 8983
      4220 9075 4265 9079
TIME...MOT...LOC 2143Z 275DEG 44KT 4249 9047 4221 9044 

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

$$

Ervin

579 
WWUS53 KDVN 242154
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
454 PM CDT Tue Aug 24 2021

ILC085-177-IAC061-097-242215-
/O.CON.KDVN.SV.W.0091.000000T0000Z-210824T2215Z/
Jo Daviess IL-Stephenson IL-Jackson IA-Dubuque IA-
454 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR JO DAVIESS...WESTERN STEPHENSON...NORTH CENTRAL JACKSON AND EAST
CENTRAL DUBUQUE COUNTIES...

At 453 PM CDT, severe thunderstorms were located along a line
extending from Council Hill to near Hanover, moving east at 45 mph.

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

SOURCE...Trained weather spotters.

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

Locations impacted include...
Dubuque, Galena, Lena, Bellevue, Stockton, East Dubuque, Warren,
Hanover, Pearl City, Elizabeth, Woodbine, Scales Mound, Apple River,
Winslow, Menominee, Council Hill, St. Donatus, Nora, Schapville and
Massbach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4243 9067 4251 9070 4250 8974 4220 8983
      4220 9066 4230 9060
TIME...MOT...LOC 2153Z 271DEG 37KT 4249 9034 4221 9031 

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

$$

Ervin

258 
WWUS53 KDVN 242209
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
509 PM CDT Tue Aug 24 2021

IAC061-097-ILC085-177-242218-
/O.EXP.KDVN.SV.W.0091.000000T0000Z-210824T2215Z/
Jo Daviess IL-Stephenson IL-Jackson IA-Dubuque IA-
509 PM CDT Tue Aug 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR JO DAVIESS...WESTERN
STEPHENSON...NORTH CENTRAL JACKSON AND EAST CENTRAL DUBUQUE COUNTIES
WILL EXPIRE AT 515 PM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 700 PM CDT for
northwestern Illinois...and northeastern and east central Iowa.

Remember, a Severe Thunderstorm Warning still remains in effect for 
eastern Jo Daviess, southeast Jackson, and all of Stephenson County 
until 6 PM.

LAT...LON 4243 9067 4251 9070 4250 8974 4220 8983
      4220 9066 4230 9060
TIME...MOT...LOC 2208Z 271DEG 37KT 4249 9015 4221 9012 

$$

Ervin

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 24, 2:21 PM CDT	Severe Thunderstorm Warning	DVN	Buchanan	39 min
Aug 24, 2:49 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	Benton, Buchanan, Delaware, Jones, Linn	56 min
Aug 24, 3:03 PM CDT	Severe Thunderstorm Warning Destructive damage threat	DVN	Buchanan, Delaware, Dubuque	42 min
Aug 24, 3:38 PM CDT	Tornado Warning	DVN	Dubuque	25 min
Aug 24, 3:42 PM CDT	Severe Thunderstorm Warning Destructive damage threat	DVN	Delaware, Dubuque	48 min
Aug 24, 4:07 PM CDT	Special Weather Statement	DVN	Cedar, Clinton, Jackson, Johnson	23 min
Aug 24, 4:54 PM CDT	Special Weather Statement	DVN	Benton	36 min
Aug 24, 5:01 PM CDT	Severe Thunderstorm Warning	DVN	Jackson	59 min
Aug 24, 5:05 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Iowa	40 min
Aug 24, 5:23 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Scott	37 min
Aug 24, 5:27 PM CDT	Special Weather Statement	DVN	Johnson	48 min
Aug 24, 6:07 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Johnson, Linn	38 min
Aug 24, 6:49 PM CDT	Special Weather Statement	DVN	Scott	41 min
Aug 24, 5:46 PM CDT	Severe Thunderstorm Warning	DVN	Bureau, Henry, Mercer, Rock Island, Whiteside	44 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 Severe Thunderstorm Warnings in Illinois, 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.