Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 26, NWS Quad Cities, IA

August 26, 2021Jefferson County, Keokuk County, Iowa

NWS Quad Cities, IA issued this tornado warning at Aug 26, 2021, 11:20 PM CDT for Jefferson County, Keokuk County, Iowa. It was in force for 27 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 26, 2021, 11:20 PM CDT (04:20 UTC)
Expired: Aug 26, 2021, 11:47 PM CDT
In force: 27 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Jefferson County, IA, Keokuk County, IA

The radar

The Quad Cities radar (KDVN), 128 km from the middle of the area, began a volume at 04:23 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 00:00Z, 4.3 hours before the alert went out and 135 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: 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

Open this sounding in Storm Lab

The text

As transmitted.

707 
WFUS53 KDVN 270420
TORDVN
IAC101-107-270500-
/O.NEW.KDVN.TO.W.0026.210827T0420Z-210827T0500Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
1120 PM CDT Thu Aug 26 2021

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Southeastern Keokuk County in southeastern Iowa...
  Northwestern Jefferson County in southeastern Iowa...

* Until midnight CDT.
    
* At 1120 PM CDT, a severe thunderstorm capable of producing a
  tornado was located near Packwood, or 12 miles southeast of
  Sigourney, moving southeast at 20 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Richland and Packwood around 1130 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Maharishi Vedic City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4128 9206 4117 9194 4116 9194 4116 9193
      4109 9186 4101 9202 4122 9217
TIME...MOT...LOC 0420Z 320DEG 19KT 4118 9208 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Gibbs

3 follow-up statements

165 
WWUS53 KDVN 270426
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1126 PM CDT Thu Aug 26 2021

IAC101-107-270500-
/O.CON.KDVN.TO.W.0026.000000T0000Z-210827T0500Z/
Keokuk IA-Jefferson IA-
1126 PM CDT Thu Aug 26 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT FOR
SOUTHEASTERN KEOKUK AND NORTHWESTERN JEFFERSON COUNTIES...
    
At 1125 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Packwood, or 11 miles northwest of Fairfield, moving
southeast at 20 mph.

HAZARD...Tornado and golf ball size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
  Maharishi Vedic City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

This is a dangerous storm, capable of producing large hail driven by
severe winds! SEEK SHELTER NOW inside a sturdy structure and stay
away from windows! If you are caught outdoors, cover your head and
neck.

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

&&

LAT...LON 4128 9206 4117 9194 4116 9194 4116 9193
      4109 9186 4101 9202 4122 9217
TIME...MOT...LOC 0425Z 320DEG 19KT 4116 9205 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.75 IN

$$

Gibbs

161 
WWUS53 KDVN 270440
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1140 PM CDT Thu Aug 26 2021

IAC101-107-270500-
/O.CON.KDVN.TO.W.0026.000000T0000Z-210827T0500Z/
Keokuk IA-Jefferson IA-
1140 PM CDT Thu Aug 26 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT FOR
SOUTHEASTERN KEOKUK AND NORTH CENTRAL JEFFERSON COUNTIES...
    
At 1140 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Richland, or 10 miles north of Fairfield, moving
southeast at 20 mph.

HAZARD...Tornado and ping pong ball size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Richland and Ollie. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

This is a dangerous storm, capable of producing large hail driven by
severe winds! SEEK SHELTER NOW inside a sturdy structure and stay
away from windows! If you are caught outdoors, cover your head and
neck.

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

&&

LAT...LON 4117 9194 4116 9194 4116 9193 4109 9186
      4108 9199 4120 9209 4122 9199
TIME...MOT...LOC 0440Z 294DEG 18KT 4115 9195 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.50 IN

$$

Gibbs

809 
WWUS53 KDVN 270447
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1147 PM CDT Thu Aug 26 2021

IAC101-107-270456-
/O.CAN.KDVN.TO.W.0026.000000T0000Z-210827T0500Z/
Keokuk IA-Jefferson IA-
1147 PM CDT Thu Aug 26 2021

...THE TORNADO WARNING FOR SOUTHEASTERN KEOKUK AND NORTH CENTRAL
JEFFERSON COUNTIES IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has weakened. 
Therefore, the warning has been cancelled.  However small hail, 
gusty winds and heavy rain are still possible with this thunderstorm.

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

Remember, a Severe Thunderstorm Warning still remains in effect for
Jefferson County through 1230 AM CDT.

LAT...LON 4117 9194 4116 9194 4116 9193 4109 9186
      4108 9199 4120 9209 4122 9199
TIME...MOT...LOC 0445Z 320DEG 19KT 4112 9192 

$$

Gibbs

The 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, 9:21 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Keokuk	39 min
Aug 26, 9:58 PM CDT	Severe Thunderstorm Warning Considerable damage threat	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 Considerable damage threat	DVN	Keokuk, Washington	47 min
Aug 26, 10:57 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DVN	Jefferson, Washington	48 min
Aug 26, 11:39 PM CDT	Severe Thunderstorm Warning Considerable damage threat	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

Tornado Warnings in Iowa, 2021 Every tornado warning in 2021 Tornadoes 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.