Alert archive / Iowa / Tornado Warnings in 2013

Tornado Warning 8, NWS Des Moines, IA

May 20, 2013Hardin County, Marshall County, Story County, Iowa

NWS Des Moines, IA issued this tornado warning at May 20, 2013, 7:24 PM CDT for Hardin County, Marshall County, Story County, Iowa. It was in force for 36 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
May 20, 2013, 7:24 PM CDT (00:24 UTC)
Expired
May 20, 2013, 8:00 PM CDT
In force
36 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Hardin County, IA, Marshall County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 61 km from the middle of the area, began a volume at 00:24 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
May 20, 7:24 PM CDTHAIL 11 Nw Nevada, IAMAINLY PEA SIZE HAIL WITH STONES UP TO QUARTER SIZE.
May 20, 7:25 PM CDTHAIL 0.75Nevada, IA
May 20, 8:10 PM CDTTSTM WND GST 601 S Union, IAPEA TO DIME SIZE HAIL.

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.

IssuedProductOfficeLasted
May 20, 6:35 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.4 hours before the alert went out and 232 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, Davenport, at 00:00Z on 2013-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 195 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, Davenport, at 00:00Z on 2013-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 square meters per square second.1939587897Sfc1 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
195 J/kg
Mixed-layer CIN
-189 J/kg
Mixed-layer LCL
1801 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

234 
WFUS53 KDMX 210024
TORDMX
IAC083-127-169-210100-
/O.NEW.KDMX.TO.W.0008.130521T0024Z-130521T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
724 PM CDT MON MAY 20 2013

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN HARDIN COUNTY IN CENTRAL IOWA...
  NORTHWESTERN MARSHALL COUNTY IN CENTRAL IOWA...
  EASTERN STORY COUNTY IN CENTRAL IOWA...

* UNTIL 800 PM CDT

* AT 719 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED NEAR NEVADA...AND MOVING NORTHEAST AT 45 MPH.

  HAZARD...DEVELOPING TORNADO AND QUARTER SIZE HAIL.

  SOURCE...RADAR INDICATED ROTATION.

  IMPACT...MOBILE HOMES WILL BE HEAVILY DAMAGED OR DESTROYED.
           SIGNIFICANT DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL
           OCCUR. FLYING DEBRIS WILL BE DEADLY TO PEOPLE AND ANIMALS.
           EXTENSIVE TREE DAMAGE IS LIKELY.

* LOCATIONS IMPACTED INCLUDE...
  STATE CENTER...COLO...ZEARING...ST. ANTHONY...CLEMONS...ALBION...
  UNION AND LISCOMB.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4229 9312 4210 9291 4191 9339 4205 9355
TIME...MOT...LOC 0024Z 232DEG 38KT 4202 9337

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

$$

AWB
3 follow-up statements
923 
WWUS53 KDMX 210034
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
734 PM CDT MON MAY 20 2013

IAC083-127-169-210100-
/O.CON.KDMX.TO.W.0008.000000T0000Z-130521T0100Z/
STORY IA-MARSHALL IA-HARDIN IA-
734 PM CDT MON MAY 20 2013

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL HARDIN...
NORTHWESTERN MARSHALL AND NORTHEASTERN STORY COUNTIES UNTIL 800 PM
CDT...

AT 732 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 7 MILES NORTHWEST OF STATE CENTER...AND MOVING NORTHEAST
AT 45 MPH.

HAZARD...DEVELOPING TORNADO AND QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED ROTATION.

IMPACT...MOBILE HOMES WILL BE HEAVILY DAMAGED OR DESTROYED.
         SIGNIFICANT DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL
         OCCUR. FLYING DEBRIS WILL BE DEADLY TO PEOPLE AND ANIMALS.
         EXTENSIVE TREE DAMAGE IS LIKELY.

LOCATIONS IMPACTED INCLUDE...
STATE CENTER...ZEARING...ST. ANTHONY...CLEMONS...ALBION AND LISCOMB.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4195 9331 4209 9349 4229 9312 4210 9291
TIME...MOT...LOC 0034Z 232DEG 38KT 4209 9326

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

$$

AWB
972 
WWUS53 KDMX 210050
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
750 PM CDT MON MAY 20 2013

IAC083-127-169-210100-
/O.CON.KDMX.TO.W.0008.000000T0000Z-130521T0100Z/
STORY IA-MARSHALL IA-HARDIN IA-
750 PM CDT MON MAY 20 2013

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN HARDIN...
NORTHWESTERN MARSHALL AND NORTHEASTERN STORY COUNTIES UNTIL 800 PM
CDT...

AT 750 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 11 MILES WEST OF CONRAD...AND MOVING NORTHEAST AT 45 MPH.

HAZARD...DEVELOPING TORNADO AND QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED ROTATION.

IMPACT...MOBILE HOMES WILL BE HEAVILY DAMAGED OR DESTROYED.
         SIGNIFICANT DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL
         OCCUR. FLYING DEBRIS WILL BE DEADLY TO PEOPLE AND ANIMALS.
         EXTENSIVE TREE DAMAGE IS LIKELY.

LOCATIONS IMPACTED INCLUDE...
LISCOMB.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4199 9322 4215 9338 4229 9312 4210 9291
TIME...MOT...LOC 0051Z 232DEG 38KT 4220 9307

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

$$

AWB
643 
WWUS53 KDMX 210058
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
758 PM CDT MON MAY 20 2013

IAC083-127-169-210108-
/O.EXP.KDMX.TO.W.0008.000000T0000Z-130521T0100Z/
STORY IA-MARSHALL IA-HARDIN IA-
758 PM CDT MON MAY 20 2013

...THE TORNADO WARNING FOR SOUTHEASTERN HARDIN...NORTHWESTERN
MARSHALL AND NORTHEASTERN STORY COUNTIES WILL EXPIRE AT 800 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
 HOWEVER SMALL HAIL...GUSTY WINDS AND HEAVY RAIN ARE STILL POSSIBLE
WITH THIS THUNDERSTORM.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1 AM. 

LAT...LON 4199 9322 4215 9338 4229 9312 4210 9291
TIME...MOT...LOC 0058Z 232DEG 38KT 4225 9299

$$

AWB

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 7:10 PM CDTTornado WarningDMXPolk, Story35 min
May 20, 7:39 PM CDTTornado WarningDMXJasper, Marshall, Polk, Story36 min
May 20, 7:59 PM CDTSevere Thunderstorm WarningDMXGrundy, Hardin, Marshall, Story31 min
May 20, 8:13 PM CDTSevere Thunderstorm WarningDMXGrundy, Marshall, Tama32 min
May 20, 8:21 PM CDTSevere Thunderstorm WarningDMXMadison, Warren24 min
May 20, 8:22 PM CDTSevere Thunderstorm WarningDMXDecatur38 min
May 20, 8:26 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Butler, Grundy, Hardin49 min
May 20, 8:35 PM CDTSevere Thunderstorm WarningDMXFranklin25 min
May 20, 8:45 PM CDTSevere Thunderstorm WarningDMXJasper, Marion, Polk, Warren30 min
May 20, 9:11 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Wayne34 min
May 20, 9:14 PM CDTSevere Thunderstorm WarningDMXMarshall, Tama31 min

Nearby

Tornado Warnings in Iowa, 2013Every tornado warning in 2013Tornadoes in 2013

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.