Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 51, NWS Des Moines, IA

July 5, 2011Boone County, Webster County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 5, 2011, 5:52 PM CDT for Boone County, Webster County, Iowa. It was in force for 23 min. 1 report 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 5, 2011, 5:52 PM CDT (22:52 UTC)
Expired
Jul 5, 2011, 6:15 PM CDT
In force
23 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon

Counties Boone County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 63 km from the middle of the area, began a volume at 22:52 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 5, 6:15 PM CDTTSTM WND DMG1 N Boxholm, IACORN FLATTENED BY WIND GUST.

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, 10.9 hours before the alert went out and 212 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 2011-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 939 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 2011-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 square meters per square second.193958Sfc1 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
939 J/kg
Mixed-layer CIN
-259 J/kg
Mixed-layer LCL
1038 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.8

Open this sounding in Storm Lab

The text

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

916 
WFUS53 KDMX 052252
TORDMX
IAC015-187-052315-
/O.NEW.KDMX.TO.W.0051.110705T2252Z-110705T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
552 PM CDT TUE JUL 5 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN BOONE COUNTY IN CENTRAL IOWA...
  SOUTH CENTRAL WEBSTER COUNTY IN CENTRAL IOWA...

* UNTIL 615 PM CDT

* AT 547 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 9 MILES EAST OF GOWRIE...OR 15 MILES SOUTH OF
  FORT DODGE...AND MOVING SOUTH AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  DAYTON...BOXHOLM...PILOT MOUND AND FRASER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IMMEDIATELY SEEK SHELTER IN A BASEMENT...
OR IN AN INTERIOR ROOM OF A REINFORCED BUILDING. STAY AWAY FROM
WINDOWS.

IF YOU ARE OUTSIDE...IN A MOBILE HOME...OR IN A VEHICLE...SEEK
SHELTER IN A NEARBY REINFORCED BUILDING. AS A LAST RESORT...FIND THE
LOWEST SPOT AVAILABLE AND COVER YOUR HEAD.

&&

LAT...LON 4236 9404 4209 9394 4205 9416 4214 9417
      4221 9417 4221 9418 4233 9420
TIME...MOT...LOC 2252Z 342DEG 27KT 4226 9410

$$

ZOGG
2 follow-up statements
884 
WWUS53 KDMX 052258
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
558 PM CDT TUE JUL 5 2011

IAC015-187-052315-
/O.CON.KDMX.TO.W.0051.000000T0000Z-110705T2315Z/
BOONE IA-WEBSTER IA-
558 PM CDT TUE JUL 5 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL WEBSTER AND
NORTHWESTERN BOONE COUNTIES UNTIL 615 PM CDT...

AT 556 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 10 MILES EAST OF GOWRIE...OR 18 MILES SOUTH OF FORT
DODGE...MOVING SOUTH AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
  BOXHOLM...PILOT MOUND AND FRASER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IMMEDIATELY SEEK SHELTER IN A BASEMENT...
OR IN AN INTERIOR ROOM OF A REINFORCED BUILDING. STAY AWAY FROM
WINDOWS.

IF YOU ARE OUTSIDE...IN A MOBILE HOME...OR IN A VEHICLE...SEEK
SHELTER IN A NEARBY REINFORCED BUILDING. AS A LAST RESORT...FIND THE
LOWEST SPOT AVAILABLE AND COVER YOUR HEAD.

&&

LAT...LON 4231 9419 4234 9404 4209 9394 4205 9416
TIME...MOT...LOC 2259Z 339DEG 23KT 4224 9408

$$

ZOGG
998 
WWUS53 KDMX 052309
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
609 PM CDT TUE JUL 5 2011

IAC015-187-052319-
/O.EXP.KDMX.TO.W.0051.000000T0000Z-110705T2315Z/
BOONE IA-WEBSTER IA-
609 PM CDT TUE JUL 5 2011

...THE TORNADO WARNING FOR SOUTH CENTRAL WEBSTER AND NORTHWESTERN
BOONE COUNTIES WILL EXPIRE AT 615 PM CDT...

THE TORNADO THREAT HAS DIMINISHED...THEREFORE THE TORNADO WARNING HAS
EXPIRED. HOWEVER...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT
FOR THE AREA.  HOWEVER GUSTY WINDS ARE STILL POSSIBLE WITH THIS
THUNDERSTORM.

LAT...LON 4231 9419 4234 9404 4209 9394 4205 9416
TIME...MOT...LOC 2309Z 339DEG 23KT 4218 9405

$$

ZOGG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 5, 3:10 PM CDTSevere Thunderstorm WarningDMXHancock, Kossuth27 min
Jul 5, 3:36 PM CDTSevere Thunderstorm WarningDMXHumboldt, Kossuth39 min
Jul 5, 4:45 PM CDTSevere Thunderstorm WarningDMXHamilton, Humboldt, Webster, Wright45 min
Jul 5, 5:43 PM CDTSevere Thunderstorm WarningDMXBoone, Greene, Webster47 min
Jul 5, 6:28 PM CDTSevere Thunderstorm WarningDMXBoone, Dallas47 min

Nearby

Tornado Warnings in Iowa, 2011Every tornado warning in 2011Tornadoes in 2011

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.