Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 5, NWS Quad Cities, IA

June 20, 2021Keokuk County, Washington County, Iowa

NWS Quad Cities, IA issued this tornado warning at Jun 20, 2021, 8:28 PM CDT for Keokuk County, Washington County, Iowa. It was in force for 32 min. 3 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: Jun 20, 2021, 8:28 PM CDT (01:28 UTC)
Expired: Jun 20, 2021, 9:00 PM CDT
In force: 32 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Keokuk County, IA, Washington County, IA

The radar

The Quad Cities radar (KDVN), 113 km from the middle of the area, began a volume at 01:27 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
Jun 20, 8:47 PM CDT	HAIL 1.25	2 W West Chester, IA	METEOROLOGIST CHASING STORMS REPORT. LOTS OF QUARTER SIZE HAIL AND A FEW HALF DOLLAR SIZE. DELAYED REPORT FROM JUNE 20, 2021.
Jun 20, 8:49 PM CDT	HAIL 0.25	Washington, IA
Jun 20, 8:59 PM CDT	TSTM WND DMG	Washington, IA	FEW DOWNED LIMBS, ROOF OFF BASEBALL CLUBHOUSE (OUTBUILDING), UNSPECIFIED DAMAGE AT THE FAIRGROUNDS, POWER OUT IN SPOTS AROUND TOWN.

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
Jun 20, 4:01 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.5 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-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: 1058 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 1009 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 174 m²/s²
0-3 km storm-relative helicity: 230 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 7.8

Open this sounding in Storm Lab

The text

As transmitted.

083 
WFUS53 KDVN 210128
TORDVN
IAC107-183-210200-
/O.NEW.KDVN.TO.W.0005.210621T0128Z-210621T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
828 PM CDT Sun Jun 20 2021

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  East central Keokuk County in southeastern Iowa...
  Southwestern Washington County in southeastern Iowa...

* Until 900 PM CDT.
    
* At 828 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Harper, or 12 miles east of Sigourney, moving east
  at 30 mph.

  HAZARD...Tornado and quarter 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...
  Washington.

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.

&&

LAT...LON 4124 9202 4135 9203 4137 9160 4118 9161
TIME...MOT...LOC 0128Z 278DEG 27KT 4129 9197 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Speck

2 follow-up statements

010 
WWUS53 KDVN 210140
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
840 PM CDT Sun Jun 20 2021

IAC107-210150-
/O.CAN.KDVN.TO.W.0005.000000T0000Z-210621T0200Z/
Keokuk IA-
840 PM CDT Sun Jun 20 2021

...THE TORNADO WARNING FOR EAST CENTRAL KEOKUK COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
southeastern Iowa.

LAT...LON 4122 9190 4133 9187 4133 9161 4118 9161
TIME...MOT...LOC 0140Z 278DEG 27KT 4128 9185 

$$

IAC183-210200-
/O.CON.KDVN.TO.W.0005.000000T0000Z-210621T0200Z/
Washington IA-
840 PM CDT Sun Jun 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 900 PM CDT FOR
SOUTHWESTERN WASHINGTON COUNTY...
    
At 840 PM CDT, a severe thunderstorm capable of producing a tornado
was located 7 miles north of Brighton, or 8 miles west of Washington,
moving east at 30 mph.

HAZARD...Tornado and quarter 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...
Washington, Washington County Fairgrounds and Washington Airport. 

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.

&&

LAT...LON 4122 9190 4133 9187 4133 9161 4118 9161
TIME...MOT...LOC 0140Z 278DEG 27KT 4128 9185 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Speck

590 
WWUS53 KDVN 210150
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
850 PM CDT Sun Jun 20 2021

IAC183-210200-
/O.EXP.KDVN.TO.W.0005.000000T0000Z-210621T0200Z/
Washington IA-
850 PM CDT Sun Jun 20 2021

...THE TORNADO WARNING FOR SOUTHWESTERN WASHINGTON COUNTY WILL EXPIRE
AT 900 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
southeastern Iowa.

LAT...LON 4122 9190 4133 9187 4133 9161 4118 9161
TIME...MOT...LOC 0150Z 278DEG 27KT 4127 9176 

$$

Speck

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 7:08 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Keokuk	38 min
Jun 20, 7:08 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque, Jones, Linn	52 min
Jun 20, 7:37 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan, Linn	38 min
Jun 20, 7:48 PM CDT	Tornado Warning	DVN	Dubuque, Jackson, Jones	42 min
Jun 20, 8:04 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Lee, Van Buren	41 min
Jun 20, 8:18 PM CDT	Severe Thunderstorm Warning	DVN	Keokuk, Washington	42 min
Jun 20, 8:19 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jackson, Jones	41 min
Jun 20, 8:27 PM CDT	Tornado Warning Tornado observed	DVN	Jackson	33 min
Jun 20, 8:37 PM CDT	Tornado Warning	DVN	Des Moines, Lee	39 min
Jun 20, 8:47 PM CDT	Special Weather Statement	DVN	Jones, Linn	43 min
Jun 20, 8:53 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jackson	67 min
Jun 20, 8:59 PM CDT	Special Weather Statement	DVN	Louisa	31 min
Jun 20, 9:29 PM CDT	Special Weather Statement	DVN	Lee	46 min
Jun 20, 9:36 PM CDT	Special Weather Statement	DVN	Scott	39 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.