Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 4, NWS Des Moines, IA

June 20, 2021Mahaska County, Marion County, Iowa

NWS Des Moines, IA issued this tornado warning at Jun 20, 2021, 6:59 PM CDT for Mahaska County, Marion County, Iowa. It was in force for 31 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, 6:59 PM CDT (23:59 UTC)
Expired: Jun 20, 2021, 7:30 PM CDT
In force: 31 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Mahaska County, IA, Marion County, IA

The radar

The Des Moines radar (KDMX), 87 km from the middle of the area, began a volume at 00:00 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 12:00Z, 12.0 hours before the alert went out and 191 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2060 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 102 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

965 
WFUS53 KDMX 202359
TORDMX
IAC123-125-210030-
/O.NEW.KDMX.TO.W.0004.210620T2359Z-210621T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
659 PM CDT Sun Jun 20 2021

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  East central Marion County in south central Iowa...
  Northwestern Mahaska County in south central Iowa...

* Until 730 PM CDT.
    
* At 659 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Pella, moving east at 25 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.

* Locations impacted include...
  New Sharon.

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.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Des Moines .

&&

LAT...LON 4138 9290 4146 9289 4148 9260 4134 9259
TIME...MOT...LOC 2359Z 266DEG 22KT 4142 9280 

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

$$

REV

2 follow-up statements

748 
WWUS53 KDMX 210008
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
708 PM CDT Sun Jun 20 2021

IAC125-210018-
/O.CAN.KDMX.TO.W.0004.000000T0000Z-210621T0030Z/
Marion IA-
708 PM CDT Sun Jun 20 2021

...THE TORNADO WARNING FOR EAST CENTRAL MARION 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
south central Iowa.

LAT...LON 4134 9259 4138 9287 4146 9287 4148 9260
TIME...MOT...LOC 0008Z 266DEG 22KT 4142 9274 

$$

IAC123-210030-
/O.CON.KDMX.TO.W.0004.000000T0000Z-210621T0030Z/
Mahaska IA-
708 PM CDT Sun Jun 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR
NORTHWESTERN MAHASKA COUNTY...
    
At 708 PM CDT, a severe thunderstorm capable of producing a tornado
was located near New Sharon, or 9 miles east of Pella, moving east at
25 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.

Locations impacted include...
New Sharon.

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.

If a tornado or other severe weather is spotted, report it to the
National Weather Service or your local nearest law enforcement agency
who will send your report. This act may save lives of others in the
path of dangerous weather.

&&

LAT...LON 4134 9259 4138 9287 4146 9287 4148 9260
TIME...MOT...LOC 0008Z 266DEG 22KT 4142 9274 

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

$$

REV

744 
WWUS53 KDMX 210025
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
725 PM CDT Sun Jun 20 2021

IAC123-210035-
/O.EXP.KDMX.TO.W.0004.000000T0000Z-210621T0030Z/
Mahaska IA-
725 PM CDT Sun Jun 20 2021

...THE TORNADO WARNING FOR NORTHWESTERN MAHASKA COUNTY WILL EXPIRE AT
730 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.  However small hail
and gusty winds are still possible with this thunderstorm.

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

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

LAT...LON 4134 9259 4138 9287 4146 9287 4148 9260
TIME...MOT...LOC 0025Z 266DEG 22KT 4143 9262 

$$

REV

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 3:38 PM CDT	Special Weather Statement	DMX	Dallas	37 min
Jun 20, 4:20 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Madison, Union	55 min
Jun 20, 4:47 PM CDT	Severe Thunderstorm Warning	DMX	Jasper	43 min
Jun 20, 4:53 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Ringgold, Union	52 min
Jun 20, 4:54 PM CDT	Severe Thunderstorm Warning	DMX	Bremer, Butler, Franklin	51 min
Jun 20, 5:33 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Poweshiek	42 min
Jun 20, 5:35 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Lucas, Wayne	40 min
Jun 20, 5:55 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion	50 min
Jun 20, 5:59 PM CDT	Severe Thunderstorm Warning	DMX	Decatur, Wayne	46 min
Jun 20, 6:04 PM CDT	Tornado Warning	DMX	Decatur	26 min
Jun 20, 6:13 PM CDT	Severe Thunderstorm Warning	DMX	Poweshiek	62 min
Jun 20, 6:15 PM CDT	Severe Thunderstorm Warning	DMX	Decatur, Wayne	30 min
Jun 20, 6:20 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk	55 min
Jun 20, 6:37 PM CDT	Tornado Warning	DMX	Mahaska, Marion	23 min
Jun 20, 6:43 PM CDT	Severe Thunderstorm Warning	DMX	Decatur, Wayne	47 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.