Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 59, NWS Des Moines, IA

July 9, 20215 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 9, 2021, 1:01 PM CDT for 5 counties in Iowa. It was in force for 44 min. 11 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
Jul 9, 2021, 1:01 PM CDT (18:01 UTC)
Expired
Jul 9, 2021, 1:45 PM CDT
In force
44 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
2.5 in
Wind
60.0 mph

Counties Boone County, IA, Dallas County, IA, Greene County, IA, Polk County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 34 km from the middle of the area, began a volume at 18:04 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

TimeReportWhereRemark
Jul 9, 1:02 PM CDTHAIL 1.75Ogden, IACORRECTS PREVIOUS HAIL REPORT FROM OGDEN.
Jul 9, 1:05 PM CDTHAIL 1.75Ogden, IALASTED ABOUT 2 MIN.
Jul 9, 1:14 PM CDTHAIL 1.754 E Berkley, IA
Jul 9, 1:15 PM CDTHAIL 0.882 N Boone, IA
Jul 9, 1:21 PM CDTHAIL 1.753 Sse Berkley, IA
Jul 9, 1:23 PM CDTHAIL 13 W Luther, IA
Jul 9, 1:27 PM CDTHAIL 1.752 Nnw Woodward, IA
Jul 9, 1:28 PM CDTHAIL 2.75Woodward, IA
Jul 9, 1:29 PM CDTHAIL 2.751 Nne Woodward, IATIME ESTIMATED.
Jul 9, 1:29 PM CDTHAIL 3Woodward, IAREPORT VIA SOCIAL MEDIA.
Jul 9, 1:38 PM CDTHAIL 1.753 S Woodward, IA

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 12:00Z, 6.0 hours before the alert went out and 207 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-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 428 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 404 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
428 J/kg
Mixed-layer CIN
-350 J/kg
Mixed-layer LCL
881 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
404 m²/s²
0-3 km storm-relative helicity
551 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted.

610 
WUUS53 KDMX 091801
SVRDMX
IAC015-049-073-153-169-091845-
/O.NEW.KDMX.SV.W.0059.210709T1801Z-210709T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
101 PM CDT Fri Jul 9 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northwestern Polk County in central Iowa...
  Southeastern Greene County in west central Iowa...
  Southwestern Story County in central Iowa...
  Boone County in central Iowa...
  Northeastern Dallas County in central Iowa...

* Until 145 PM CDT.

* At 100 PM CDT, a severe thunderstorm was located over Ogden, or 10
  miles west of Boone, moving southeast at 30 mph.

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

  SOURCE...Radar indicated. This storm has a history of producing 
           large hail and the storm is intensifying. 

  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.

* Locations impacted include...
  Woodward, Madrid, Granger, Saylorville Lake and Big Creek Lake.

This includes Interstate 35 between mile markers 106 and 109.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4200 9427 4214 9399 4194 9352 4166 9405
TIME...MOT...LOC 1800Z 318DEG 27KT 4201 9406 

HAIL...2.50IN
WIND...60MPH
 
$$

Fowle
3 follow-up statements
248 
WWUS53 KDMX 091818
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
118 PM CDT Fri Jul 9 2021

IAC015-049-073-153-169-091845-
/O.CON.KDMX.SV.W.0059.000000T0000Z-210709T1845Z/
Polk IA-Greene IA-Story IA-Boone IA-Dallas IA-
118 PM CDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR NORTHWESTERN POLK...SOUTHEASTERN GREENE...SOUTHWESTERN STORY...
SOUTHERN BOONE AND NORTHEASTERN DALLAS COUNTIES...

At 116 PM CDT, a severe thunderstorm was located near Woodward, or 9
miles northeast of Perry, moving southeast at 30 mph.

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

SOURCE...Radar indicated. This storm has a history of producing golf 
         ball sized hail and even larger hail is possible. 

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.

Locations impacted include...
Ames, Boone, Perry, Huxley, Madrid, Ogden, Dallas Center, Slater,
Granger, Woodward, Boone Speedway, Big Creek Lake, Saylorville Lake,
Minburn, Sheldahl, Kelley, Rippey, Bouton, Luther and Berkley.

This includes Interstate 35 between mile markers 106 and 109.
 
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.

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 4196 9424 4211 9392 4194 9352 4166 9405
TIME...MOT...LOC 1816Z 317DEG 27KT 4192 9395 

HAIL...2.50IN
WIND...60MPH
 
$$

Fowle
169 
WWUS53 KDMX 091829
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
129 PM CDT Fri Jul 9 2021

IAC015-049-073-153-169-091845-
/O.CON.KDMX.SV.W.0059.000000T0000Z-210709T1845Z/
Polk IA-Greene IA-Story IA-Boone IA-Dallas IA-
129 PM CDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR NORTHWESTERN POLK...SOUTHEASTERN GREENE...SOUTHWESTERN STORY...
SOUTHERN BOONE AND NORTHEASTERN DALLAS COUNTIES...

At 128 PM CDT, a severe thunderstorm was located over Madrid, or 12
miles east of Perry, moving southeast at 30 mph.

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

SOURCE...Radar indicated. This storm has a history of producing 
         large hail to golf ball sized hail with larger hail to 
         tennis ball sized possible. 

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.

Locations impacted include...
Perry, Huxley, Madrid, Dallas Center, Slater, Granger, Woodward, Big
Creek Lake, Saylorville Lake, Minburn, Sheldahl, Kelley, Bouton,
Luther, Perry Municipal Airport, Big Creek State Park and Ledges
State Park.

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.

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 4188 9419 4202 9375 4190 9359 4166 9405
TIME...MOT...LOC 1828Z 318DEG 27KT 4185 9386 

HAIL...2.50IN
WIND...60MPH
 
$$

Fowle
265 
WWUS53 KDMX 091836 CCA
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
136 PM CDT Fri Jul 9 2021

IAC015-049-073-153-169-091845-
/O.COR.KDMX.SV.W.0059.000000T0000Z-210709T1845Z/
Polk IA-Greene IA-Story IA-Boone IA-Dallas IA-
136 PM CDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR NORTHWESTERN POLK...SOUTHEASTERN GREENE...SOUTHWESTERN STORY...
SOUTHERN BOONE AND NORTHEASTERN DALLAS COUNTIES...

At 135 PM CDT, a severe thunderstorm was located near Woodward, or 10
miles north of Grimes, moving southeast at 30 mph.

This is a very dangerous storm.

HAZARD...Baseball size hail and 60 mph wind gusts.

SOURCE...Radar indicated. At 128 pm, baseball sized hail was 
         reported near Woodward with this storm. 

IMPACT...People and animals outdoors will be severely injured. 
         Expect shattered windows, extensive damage to roofs, 
         siding, and vehicles.

Locations impacted include...
Perry, Huxley, Madrid, Dallas Center, Slater, Granger, Woodward, Big
Creek Lake, Saylorville Lake, Minburn, Sheldahl, Kelley, Bouton,
Luther, Perry Municipal Airport, Big Creek State Park and Ledges
State Park.

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.

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 4188 9419 4202 9375 4190 9359 4166 9405
TIME...MOT...LOC 1829Z 325DEG 25KT 4185 9386 

HAIL...2.75IN
WIND...60MPH
 
$$

Fowle

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 2:59 AM CDTFlood WatchDMXAppanoose, Davis, Monroe, Wapello, Wayne13 min
Jul 9, 3:12 AM CDTFlash Flood WatchDMXAppanoose, Clarke, Davis, Decatur, Lucas, Madison and 4 more30 hr
Jul 9, 8:09 AM CDTSevere Thunderstorm WarningDMXAdair, Adams, Union28 min
Jul 9, 9:24 AM CDTSpecial Weather StatementDMXWayne21 min
Jul 9, 12:04 PM CDTSpecial Weather StatementDMXWebster26 min
Jul 9, 12:28 PM CDTSevere Thunderstorm WarningDMXBoone, Greene, Hamilton, Webster47 min
Jul 9, 1:27 PM CDTSevere Thunderstorm WarningDMXBoone, Dallas, Madison, Polk, Story63 min
Jul 9, 2:06 PM CDTSevere Thunderstorm WarningDMXJasper, Madison, Marion, Polk, Warren54 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021Every 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.