Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 101, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 26, 2021, 9:21 PM CDT for Iowa County, Keokuk County, Iowa. It was in force for 39 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 26, 2021, 9:21 PM CDT (02:21 UTC)
- Expired
- Aug 26, 2021, 10:00 PM CDT
- In force
- 39 min
- Issued by
- NWS Quad Cities, IA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Iowa County, IA, Keokuk County, IA
The radar
The Des Moines radar (KDMX), 122 km from the middle of the area, began a volume at 02:21 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 26, 9:38 PM CDT | TSTM WND DMG | 3 N Thornburg, IA | LARGE TREE DOWN. VIA BROADCAST MEDIA. TIME OF THE EVENT WAS ESTIMATED USING 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 00:00Z, 2.4 hours before the alert went out and 150 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.
- Mixed-layer CAPE
- 673 J/kg
- Mixed-layer CIN
- -189 J/kg
- Mixed-layer LCL
- 1469 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- -106 m²/s²
- 0-3 km storm-relative helicity
- -64 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -1.7
The text
As transmitted.
302
WUUS53 KDVN 270221
SVRDVN
IAC095-107-270300-
/O.NEW.KDVN.SV.W.0101.210827T0221Z-210827T0300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
921 PM CDT Thu Aug 26 2021
The National Weather Service in the Quad Cities has issued a
* Severe Thunderstorm Warning for...
Northwestern Keokuk County in southeastern Iowa...
Southwestern Iowa County in east central Iowa...
* Until 1000 PM CDT.
* At 921 PM CDT, a severe thunderstorm was located near What Cheer,
or 11 miles southeast of Montezuma, moving southeast 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 thunderstorm will be near...
What Cheer around 930 PM CDT.
Other locations in the path of this severe thunderstorm include
Delta, Sigourney and Hayesville.
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 4151 9241 4151 9230 4170 9230 4157 9211
4125 9210 4125 9241
TIME...MOT...LOC 0221Z 323DEG 20KT 4143 9242
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Gibbs2 follow-up statements
943
WWUS53 KDVN 270231
SVSDVN
Severe Weather Statement
National Weather Service Quad Cities IA/IL
931 PM CDT Thu Aug 26 2021
IAC095-107-270300-
/O.CON.KDVN.SV.W.0101.000000T0000Z-210827T0300Z/
Keokuk IA-Iowa IA-
931 PM CDT Thu Aug 26 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR NORTHWESTERN KEOKUK AND SOUTHWESTERN IOWA COUNTIES...
At 931 PM CDT, a severe thunderstorm was located over What Cheer, or
10 miles northwest of Sigourney, moving southeast at 15 mph.
HAZARD...70 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect considerable
tree damage. Wind damage is also likely to mobile homes,
roofs, and outbuildings.
This severe storm will be near...
What Cheer around 935 PM CDT.
Other locations in the path of this severe thunderstorm include
Keswick, Delta, Sigourney and Hayesville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4151 9241 4151 9230 4161 9229 4152 9212
4125 9210 4125 9241
TIME...MOT...LOC 0231Z 315DEG 15KT 4141 9239
TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH
$$
Gibbs039
WWUS53 KDVN 270241
SVSDVN
Severe Weather Statement
National Weather Service Quad Cities IA/IL
941 PM CDT Thu Aug 26 2021
IAC095-107-270300-
/O.CON.KDVN.SV.W.0101.000000T0000Z-210827T0300Z/
Keokuk IA-Iowa IA-
941 PM CDT Thu Aug 26 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR NORTHWESTERN KEOKUK AND SOUTHWESTERN IOWA COUNTIES...
At 941 PM CDT, a severe thunderstorm was located near What Cheer, or
11 miles northwest of Sigourney, moving southeast at 20 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.
This severe storm will be near...
What Cheer around 950 PM CDT.
Other locations in the path of this severe thunderstorm include
Keswick, Delta, Sigourney and Hayesville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.
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 4151 9241 4151 9230 4161 9229 4152 9212
4125 9210 4125 9241
TIME...MOT...LOC 0241Z 324DEG 15KT 4145 9237
TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH
$$
GibbsThe office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 8:23 PM CDT | Special Weather Statement | DVN | Benton | 52 min |
| Aug 26, 9:58 PM CDT | Severe Thunderstorm Warning | DVN | Keokuk | 47 min |
| Aug 26, 10:29 PM CDT | Flash Flood Warning | DVN | Keokuk | 4 hr |
| Aug 26, 10:43 PM CDT | Severe Thunderstorm Warning | DVN | Keokuk, Washington | 47 min |
| Aug 26, 10:57 PM CDT | Severe Thunderstorm Warning | DVN | Jefferson, Washington | 48 min |
| Aug 26, 11:20 PM CDT | Tornado Warning | DVN | Jefferson, Keokuk | 27 min |
| Aug 26, 11:39 PM CDT | Severe Thunderstorm Warning | DVN | Jefferson, Washington | 31 min |
| Aug 27, 1:34 PM CDT | Heat Advisory | DVN | Lee | 29 hr |
| Aug 27, 3:07 PM CDT | Heat Advisory | DVN | Des Moines, Henry, Van Buren | 28 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.