Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 7, NWS Des Moines, IA

June 16, 2021Calhoun County, Sac County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 16, 2021, 8:57 PM CDT for Calhoun County, Sac County, Iowa. It was in force for 63 min. 7 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 16, 2021, 8:57 PM CDT (01:57 UTC)
Expired: Jun 16, 2021, 10:00 PM CDT
In force: 63 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Calhoun County, IA, Sac County, IA

The radar

The Des Moines radar (KDMX), 145 km from the middle of the area, began a volume at 01:59 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 16, 9:09 PM CDT	TSTM WND GST 60	3 Nnw Schaller, IA	HAILED FOR ABOUT 10 MINUTES. PEA TO DIME SIZE HAIL WITH THE STRONG WINDS.
Jun 16, 9:15 PM CDT	TSTM WND DMG	Schaller, IA	NUMEROUS 3 TO 6 INCH DIAMETER TREE LIMBS DOWN ACROSS SCHALLER WITH ONE LARGE PORTION OF A TREE ESTIMATED AT 12 INCHES IN DIAMETER SNAPPED OFF AND DOWN IN FRONT OF A RESIDENCE. TOWN WAS OUT OF POWER AS OF 1025PM. TIME OF DAMAGE ESTIMATED FROM RADAR.
Jun 16, 9:16 PM CDT	HAIL 1	1 Sse Schaller, IA	DIME TO QUARTER SIZED HAIL LAYING ON THE GROUND BEHIND SEVERE STORM AT US 20 AND HIGHWAY 110. TIME ESTIMATED FROM RADAR.
Jun 16, 9:18 PM CDT	HAIL 1.5	Schaller, IA
Jun 16, 9:24 PM CDT	HAIL 0.75	3 Se Schaller, IA	REPORT FROM MPING: DIME (0.75 IN.).
Jun 16, 9:30 PM CDT	TSTM WND DMG	2 Ene Odebolt, IA	HEALTHY 13 INCH DIAMETER TREE LIMB DOWN. TIME ESTIMATED FROM RADAR.
Jun 16, 9:34 PM CDT	TSTM WND DMG	Odebolt, IA	STRONG WINDS HAVE BROUGHT DOWN NUMEROUS 12 TO 16 INCH DIAMETER TREE LIMBS THROUGHOUT THE CITY OF ODEBOLDT WITH NUMEROUS ROADS BLOCKED. SOME DOWNED TREES LIMBS DO HAVE ROTTEN CENTERS. LARGE AREA OF ELECTRICITY OUT. DIME SIZED HAIL AS WELL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.0 hours before the alert went out and 157 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: 2997 J/kg
Mixed-layer CIN: -144 J/kg
Mixed-layer LCL: 1946 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 120 m²/s²
0-3 km storm-relative helicity: 435 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 27.9

Open this sounding in Storm Lab

The text

As transmitted.

425 
WUUS53 KDMX 170157
SVRDMX
IAC025-161-170300-
/O.NEW.KDMX.SV.W.0007.210617T0157Z-210617T0300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
857 PM CDT Wed Jun 16 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Sac County in west central Iowa...
  Western Calhoun County in west central Iowa...

* Until 1000 PM CDT.

* At 856 PM CDT, a severe thunderstorm was located near Storm Lake,
  moving south at 45 mph.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Lake View and Odebolt around 925 PM CDT.
  Black Hawk Lake around 930 PM CDT.

Other locations impacted by this severe thunderstorm include Wall
Lake, Wall Lake Municipal Airport, Lytton, Sac City Municipal
Airport, Nemaha, Auburn, Early, Schaller, Blackhawk Lake State Park
and Yetter.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

If on or near a lake, get away from the water and move indoors or 
inside a vehicle. Remember, lightning can strike out to 15 miles 
from the parent thunderstorm. If you can hear thunder, you are close 
enough to be struck by lightning. Move to safe shelter now!  Do not 
be caught on the water in a thunderstorm.

&&

LAT...LON 4256 9539 4256 9487 4221 9472 4221 9532
      4247 9532 4248 9539
TIME...MOT...LOC 0156Z 342DEG 41KT 4263 9526 

HAIL...1.50IN
WIND...60MPH
 
$$

Small

3 follow-up statements

370 
WWUS53 KDMX 170209
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
909 PM CDT Wed Jun 16 2021

IAC025-161-170300-
/O.CON.KDMX.SV.W.0007.000000T0000Z-210617T0300Z/
Sac IA-Calhoun IA-
909 PM CDT Wed Jun 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR SAC AND WESTERN CALHOUN COUNTIES...

At 908 PM CDT, a severe thunderstorm was located 7 miles southwest of
Lakeside, or 8 miles south of Storm Lake, moving south at 45 mph.

HAZARD...Two inch hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

This severe storm will be near...
  Odebolt around 925 PM CDT.
  Lake View and Black Hawk Lake around 930 PM CDT.

Other locations impacted by this severe thunderstorm include Wall
Lake, Wall Lake Municipal Airport, Lytton, Sac City Municipal
Airport, Nemaha, Auburn, Early, Schaller, Blackhawk Lake State Park
and Yetter.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.

If on or near a lake, get away from the water and move indoors or 
inside a vehicle. remember, lightning can strike out to 15 miles 
from the parent thunderstorm. If you can hear thunder, you are close 
enough to be struck by lightning. Move to safe shelter now!  Do not 
be caught on the water in a thunderstorm.

&&

LAT...LON 4256 9539 4256 9487 4221 9472 4221 9532
      4247 9532 4248 9539
TIME...MOT...LOC 0208Z 341DEG 41KT 4252 9525 

HAIL...2.00IN
WIND...60MPH
 
$$

Small

663 
WWUS53 KDMX 170234
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
934 PM CDT Wed Jun 16 2021

IAC025-170243-
/O.CAN.KDMX.SV.W.0007.000000T0000Z-210617T0300Z/
Calhoun IA-
934 PM CDT Wed Jun 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN CALHOUN COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has weakened and 
moved out of the warned area. Therefore, the warning has been 
cancelled.

LAT...LON 4247 9501 4221 9486 4221 9532 4243 9532
TIME...MOT...LOC 0233Z 340DEG 34KT 4231 9516 

$$

IAC161-170300-
/O.CON.KDMX.SV.W.0007.000000T0000Z-210617T0300Z/
Sac IA-
934 PM CDT Wed Jun 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR SOUTHERN SAC COUNTY...

At 933 PM CDT, a severe thunderstorm was located near Odebolt, or 11
miles southwest of Sac City, moving south at 40 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
southern Sac County, including the following locations... Wall Lake,
Wall Lake Municipal Airport, Blackhawk Lake State Park, Sac City
Municipal Airport and Auburn.

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.

&&

LAT...LON 4247 9501 4221 9486 4221 9532 4243 9532
TIME...MOT...LOC 0233Z 340DEG 34KT 4231 9516 

HAIL...1.75IN
WIND...60MPH
 
$$

Small

292 
WWUS53 KDMX 170300
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1000 PM CDT Wed Jun 16 2021

IAC161-170307-
/O.EXP.KDMX.SV.W.0007.000000T0000Z-210617T0300Z/
Sac IA-
1000 PM CDT Wed Jun 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN SAC COUNTY WILL
EXPIRE AT 1000 PM CDT...
        
The storm which prompted the warning has exited the warned area. 
Therefore, the warning will be allowed to expire.

However gusty winds, possibly from 40 to 55 mph, are still possible 
with this thunderstorm in its wake after the precipitation has ended.

LAT...LON 4247 9501 4221 9486 4221 9532 4243 9532
TIME...MOT...LOC 0257Z 342DEG 41KT 4207 9506 

$$

Small

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 16, 9:39 PM CDT	Severe Thunderstorm Warning	DMX	Carroll, Crawford	51 min
Jun 16, 10:18 PM CDT	Special Weather Statement	DMX	Audubon, Guthrie	42 min
Jun 16, 10:23 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll, Greene, Guthrie	53 min
Jun 16, 10:53 PM CDT	Special Weather Statement	DMX	Adair, Cass, Madison	52 min
Jun 16, 11:31 PM CDT	Special Weather Statement	DMX	Adams, Ringgold, Taylor, Union	59 min
Jun 17, 2:54 PM CDT	Special Weather Statement	DMX	Cerro Gordo, Hancock, Winnebago, Worth	66 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 Every 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.