Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 6, NWS Quad Cities, IA

June 20, 2021Des Moines County, Lee County, Iowa; Hancock County, Henderson County, Illinois

NWS Quad Cities, IA issued this tornado warning at Jun 20, 2021, 8:37 PM CDT for Des Moines County, Lee County, Iowa; Hancock County, Henderson County, Illinois. It was in force for 39 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: Jun 20, 2021, 8:37 PM CDT (01:37 UTC)
Expired: Jun 20, 2021, 9:16 PM CDT
In force: 39 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.5 in

Counties Des Moines County, IA, Lee County, IA, Hancock County, IL, Henderson County, IL

The radar

The Quad Cities radar (KDVN), 131 km from the middle of the area, began a volume at 01:40 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 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, 1.6 hours before the alert went out and 136 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.

775 
WFUS53 KDVN 210137
TORDVN
ILC067-071-IAC057-111-210230-
/O.NEW.KDVN.TO.W.0006.210621T0137Z-210621T0230Z/

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

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Northwestern Hancock County in west central Illinois...
  Southwestern Henderson County in west central Illinois...
  South central Des Moines County in southeastern Iowa...
  Central Lee County in southeastern Iowa...

* Until 930 PM CDT.
    
* At 837 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Franklin, or 8 miles west of Fort Madison, moving
  east at 30 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.

* This dangerous storm will be near...
  Nauvoo and Montrose around 850 PM CDT.
  Fort Madison around 855 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Niota, Dallas City, Colusa and Adrian.

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 4057 9159 4073 9158 4074 9102 4042 9123
TIME...MOT...LOC 0137Z 278DEG 27KT 4064 9152 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

Speck

3 follow-up statements

214 
WWUS53 KDVN 210153
SVSDVN

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

ILC067-071-IAC057-111-210230-
/O.CON.KDVN.TO.W.0006.000000T0000Z-210621T0230Z/
Hancock IL-Henderson IL-Des Moines IA-Lee IA-
853 PM CDT Sun Jun 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 PM CDT FOR
NORTHWESTERN HANCOCK...SOUTHWESTERN HENDERSON...SOUTH CENTRAL DES
MOINES AND NORTHEASTERN LEE COUNTIES...
    
At 853 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Fort Madison, moving east at 30 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...
  Niota, Dallas City and Colusa.

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 4055 9144 4073 9145 4074 9102 4047 9120
TIME...MOT...LOC 0153Z 278DEG 27KT 4062 9136 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

Speck

286 
WWUS53 KDVN 210209 RRA
SVSDVN

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

ILC067-071-IAC057-111-210230-
/O.CON.KDVN.TO.W.0006.000000T0000Z-210621T0230Z/
Hancock IL-Henderson IL-Des Moines IA-Lee IA-
909 PM CDT Sun Jun 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 PM CDT FOR NORTH
CENTRAL HANCOCK...SOUTHWESTERN HENDERSON...SOUTH CENTRAL DES MOINES
AND NORTHEASTERN LEE COUNTIES...
    
At 909 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Dallas City, or 7 miles east of Fort Madison, moving
east at 30 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...
Fort Madison, Dallas City, Carman, Colusa, Niota, Lomax, Pontoosuc
and Wever.

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 4057 9129 4073 9127 4074 9102 4053 9116
TIME...MOT...LOC 0209Z 278DEG 27KT 4060 9120 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

Speck

529 
WWUS53 KDVN 210216
SVSDVN

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

IAC057-111-ILC067-071-210226-
/O.CAN.KDVN.TO.W.0006.000000T0000Z-210621T0230Z/
Hancock IL-Henderson IL-Des Moines IA-Lee IA-
916 PM CDT Sun Jun 20 2021

...THE TORNADO WARNING FOR NORTH CENTRAL HANCOCK...SOUTHWESTERN
HENDERSON...SOUTH CENTRAL DES MOINES AND NORTHEASTERN LEE COUNTIES IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.  However gusty winds are
still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
west central Illinois...and southeastern Iowa.

LAT...LON 4057 9129 4073 9127 4074 9102 4053 9116
TIME...MOT...LOC 0214Z 278DEG 27KT 4059 9113 

$$

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, 8:28 PM CDT	Tornado Warning	DVN	Keokuk, Washington	32 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
Jun 20, 9:18 PM CDT	Special Weather Statement	DVN	Henderson	42 min
Jun 20, 9:47 PM CDT	Special Weather Statement	DVN	Bureau, Henry	43 min
Jun 20, 10:03 PM CDT	Special Weather Statement	DVN	Hancock, McDonough	27 min
Jun 20, 10:23 PM CDT	Severe Thunderstorm Warning	DVN	McDonough	22 min

Nearby

Tornado Warnings in Iowa, 2021 Tornado Warnings in Illinois, 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.