Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 89, NWS Quad Cities, IA

August 24, 2021Buchanan County, Delaware County, Dubuque County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 24, 2021, 3:03 PM CDT for Buchanan County, Delaware County, Dubuque County, Iowa. It was in force for 42 min. 6 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, 3:03 PM CDT (20:03 UTC)
Expired
Aug 24, 2021, 3:45 PM CDT
In force
42 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Damage threat
Destructive
Hail
0.75 in
Wind
80.0 mph

Counties Buchanan County, IA, Delaware County, IA, Dubuque County, IA

The radar

The Quad Cities radar (KDVN), 117 km from the middle of the area, began a volume at 20:04 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 24, 3:19 PM CDTTSTM WND DMG1 N Manchester Airport, IAEM RELAYED REPORT OF A POLE BARN FLATTENED NORTHWEST OF MANCHESTER. TIME ESTIMATED FROM RADAR.
Aug 24, 3:25 PM CDTTSTM WND DMG1 E Manchester, IAROOF PEELED OFF DOWNTOWN BUILDING. ALSO SEVERAL TREES DOWN IN DOWNTOWN. TIME ESTIMATED FROM RADAR.
Aug 24, 3:26 PM CDTHAIL 1.753 Ne Manchester Airport, IATIME ESTIMATED RADAR.
Aug 24, 3:40 PM CDTTSTM WND DMG1 W Manchester, IAREPORT FROM MPING: TREES UPROOTED OR SNAPPED; ROOF BLOWN OFF.
Aug 24, 3:41 PM CDTTSTM WND GST 60Oneida, IA
Aug 24, 3:44 PM CDTHAIL 0.7Oneida, IA

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.

IssuedProductOfficeLasted
Aug 24, 1:52 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.1 hours before the alert went out and 119 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 2021-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1809 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
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.

111 
WUUS53 KDVN 242003
SVRDVN
IAC019-055-061-242045-
/O.NEW.KDVN.SV.W.0089.210824T2003Z-210824T2045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
303 PM CDT Tue Aug 24 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Northeastern Buchanan County in northeastern Iowa...
  Northwestern Dubuque County in northeastern Iowa...
  Delaware County in northeastern Iowa...

* Until 345 PM CDT.

* At 303 PM CDT, severe thunderstorms were located along a line
  extending from near Lamont to near Masonville to near Winthrop,
  moving east at 45 mph.

  THESE ARE DESTRUCTIVE STORMS FOR northern Buchanan and northern 
Deleware counties!

  HAZARD...80 mph wind gusts.

  SOURCE...Trained weather spotters.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be heavily damaged. Expect 
           considerable damage to roofs, windows, and vehicles. 
           Extensive tree damage and power outages are likely.

* Severe thunderstorms will be near...
  Dundee around 310 PM CDT.
  Manchester and Edgewood around 320 PM CDT.

Other locations in the path of these severe thunderstorms include
Delhi, Greeley, Delaware, Oneida, Earlville, Colesburg, Dyersville,
New Vienna, Worthington, Epworth, Farley, Holy Cross, Luxemburg and
Bankston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

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

&&

LAT...LON 4267 9088 4241 9087 4235 9111 4240 9180
      4253 9176 4264 9175 4265 9090 4267 9090
TIME...MOT...LOC 2003Z 277DEG 40KT 4266 9166 4253 9167 4246 9169 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Ervin
5 follow-up statements
201 
WWUS53 KDVN 242010
SVSDVN

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

IAC019-055-061-242045-
/O.CON.KDVN.SV.W.0089.000000T0000Z-210824T2045Z/
Buchanan IA-Dubuque IA-Delaware IA-
310 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR NORTHEASTERN BUCHANAN...NORTHWESTERN DUBUQUE AND DELAWARE
COUNTIES...

At 309 PM CDT, severe thunderstorms were located along a line
extending from near Strawberry Point to near Dundee to Masonville,
moving east at 45 mph.

THESE ARE DESTRUCTIVE STORMS FOR northeast Buchanan and northern 
Deleware county!

HAZARD...80 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

These severe storms will be near...
  Manchester and Edgewood around 320 PM CDT.

Other locations in the path of these severe thunderstorms include
Delhi, Greeley, Delaware, Oneida, Earlville, Colesburg, Dyersville,
New Vienna, Worthington, Epworth, Farley, Holy Cross, Luxemburg and
Bankston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

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.

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

&&

LAT...LON 4267 9088 4241 9087 4235 9111 4240 9180
      4253 9176 4264 9175 4265 9090 4267 9090
TIME...MOT...LOC 2009Z 277DEG 40KT 4265 9157 4252 9158 4245 9160 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Ervin
546 
WWUS53 KDVN 242015
SVSDVN

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

IAC019-055-061-242045-
/O.CON.KDVN.SV.W.0089.000000T0000Z-210824T2045Z/
Buchanan IA-Dubuque IA-Delaware IA-
315 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR NORTHEASTERN BUCHANAN...NORTHWESTERN DUBUQUE AND DELAWARE
COUNTIES...

At 314 PM CDT, severe thunderstorms were located along a line
extending from near Lamont to near Masonville to near Winthrop,
moving east at 50 mph.

THESE ARE DESTRUCTIVE STORMS FOR northern Deleware and northeast 
Buchanan counties!

HAZARD...80 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

These severe storms will be near...
  Manchester and Edgewood around 325 PM CDT.
  Delhi, Greeley, Delaware and Oneida around 330 PM CDT.

Other locations in the path of these severe thunderstorms include
Earlville, Colesburg, Dyersville, New Vienna, Worthington, Luxemburg,
Farley, Holy Cross, Epworth, Bankston and Rickardsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

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.

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

&&

LAT...LON 4267 9088 4241 9087 4235 9111 4240 9180
      4253 9176 4264 9175 4265 9090 4267 9090
TIME...MOT...LOC 2014Z 280DEG 45KT 4263 9162 4250 9163 4243 9165 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Ervin
444 
WWUS53 KDVN 242020
SVSDVN

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

IAC019-055-061-242045-
/O.CON.KDVN.SV.W.0089.000000T0000Z-210824T2045Z/
Buchanan IA-Dubuque IA-Delaware IA-
320 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR NORTHEASTERN BUCHANAN...NORTHWESTERN DUBUQUE AND DELAWARE
COUNTIES...

At 320 PM CDT, severe thunderstorms were located along a line
extending from near Dundee to near Masonville to 6 miles northwest of
Ryan, moving east at 45 mph.

THESE ARE DESTRUCTIVE STORMS FOR northern Deleware county!

HAZARD...80 mph wind gusts and quarter size hail.

SOURCE...Trained weather spotters.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

These severe storms will be near...
  Manchester around 325 PM CDT.
  Edgewood around 330 PM CDT.
  Delhi, Greeley, Delaware and Oneida around 335 PM CDT.

Other locations in the path of these severe thunderstorms include
Earlville, Colesburg, Dyersville, New Vienna, Worthington, Luxemburg,
Farley, Holy Cross, Epworth, Rickardsville and Bankston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

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.

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

&&

LAT...LON 4267 9088 4241 9087 4235 9111 4240 9180
      4253 9176 4264 9175 4265 9090 4267 9090
TIME...MOT...LOC 2020Z 277DEG 40KT 4262 9153 4249 9154 4242 9156 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Ervin
710 
WWUS53 KDVN 242026
SVSDVN

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

IAC019-055-061-242045-
/O.CON.KDVN.SV.W.0089.000000T0000Z-210824T2045Z/
Buchanan IA-Dubuque IA-Delaware IA-
326 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR NORTHEASTERN BUCHANAN...NORTHWESTERN DUBUQUE AND DELAWARE
COUNTIES...

At 326 PM CDT, severe thunderstorms were located along a line
extending from near Edgewood to Manchester to near Ryan, moving east
at 45 mph.

THESE ARE DESTRUCTIVE STORMS FOR northern Deleware county.

HAZARD...80 mph wind gusts and quarter size hail.

SOURCE...Trained weather spotters.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

These severe storms will be near...
  Edgewood around 330 PM CDT.
  Delhi, Greeley, Delaware and Oneida around 335 PM CDT.
  Earlville around 340 PM CDT.

Other locations in the path of these severe thunderstorms include
Colesburg, Dyersville, New Vienna, Worthington, Farley, Luxemburg,
Holy Cross, Bankston, Epworth and Rickardsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

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.

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

&&

LAT...LON 4267 9088 4241 9087 4235 9111 4240 9180
      4252 9170 4264 9168 4265 9090 4267 9090
TIME...MOT...LOC 2026Z 277DEG 40KT 4261 9147 4248 9148 4241 9150 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Ervin
078 
WWUS53 KDVN 242033
SVSDVN

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

IAC019-242042-
/O.CAN.KDVN.SV.W.0089.000000T0000Z-210824T2045Z/
Buchanan IA-
333 PM CDT Tue Aug 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BUCHANAN COUNTY
IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 700 PM CDT for
northeastern Iowa.

LAT...LON 4267 9088 4241 9087 4235 9111 4239 9160
      4250 9157 4264 9156 4265 9090 4267 9090
TIME...MOT...LOC 2032Z 270DEG 40KT 4260 9139 4247 9140 4240 9142 

$$

IAC055-061-242045-
/O.CON.KDVN.SV.W.0089.000000T0000Z-210824T2045Z/
Dubuque IA-Delaware IA-
333 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR NORTHWESTERN DUBUQUE AND DELAWARE COUNTIES...

At 332 PM CDT, severe thunderstorms were located along a line
extending from Edgewood to near Manchester to near Ryan, moving east
at 45 mph.

THESE ARE DESTRUCTIVE STORMS FOR northern Deleware county.

HAZARD...80 mph wind gusts and golf ball size hail.

SOURCE...Trained weather spotters.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

These severe storms will be near...
  Earlville around 340 PM CDT.
  Colesburg around 345 PM CDT.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

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.

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

&&

LAT...LON 4267 9088 4241 9087 4235 9111 4239 9160
      4250 9157 4264 9156 4265 9090 4267 9090
TIME...MOT...LOC 2032Z 270DEG 40KT 4260 9139 4247 9140 4240 9142 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Ervin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 24, 2:21 PM CDTSevere Thunderstorm WarningDVNBuchanan39 min
Aug 24, 2:49 PM CDTSevere Thunderstorm Warning Considerable damage threatDVNBenton, Buchanan, Delaware, Jones, Linn56 min
Aug 24, 3:38 PM CDTTornado WarningDVNDubuque25 min
Aug 24, 3:42 PM CDTSevere Thunderstorm Warning Destructive damage threatDVNDelaware, Dubuque48 min
Aug 24, 4:07 PM CDTSpecial Weather StatementDVNCedar, Clinton, Jackson, Johnson23 min
Aug 24, 4:17 PM CDTSevere Thunderstorm Warning Considerable damage threatDVNDubuque, Jackson58 min
Aug 24, 4:54 PM CDTSpecial Weather StatementDVNBenton36 min
Aug 24, 5:01 PM CDTSevere Thunderstorm WarningDVNJackson59 min
Aug 24, 5:05 PM CDTSevere Thunderstorm WarningDVNBenton, Iowa40 min
Aug 24, 5:23 PM CDTSevere Thunderstorm WarningDVNClinton, Scott37 min
Aug 24, 5:27 PM CDTSpecial Weather StatementDVNJohnson48 min
Aug 24, 6:07 PM CDTSevere Thunderstorm WarningDVNCedar, Johnson, Linn38 min
Aug 24, 6:49 PM CDTSpecial Weather StatementDVNScott41 min

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.