Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 33, NWS Des Moines, IA

May 11, 2011Adams County, Taylor County, Iowa

NWS Des Moines, IA issued this tornado warning at May 11, 2011, 4:11 PM CDT for Adams County, Taylor County, Iowa. It was in force for 49 min. 4 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 11, 2011, 4:11 PM CDT (21:11 UTC)
Expired
May 11, 2011, 5:00 PM CDT
In force
49 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon

Counties Adams County, IA, Taylor County, IA

The radar

The Des Moines radar (KDMX), 123 km from the middle of the area, began a volume at 21:15 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 11, 4:22 PM CDTTORNADOSharpsburg, IABRIEF TORNADO NEAR SHARPSBURG. FROM GRAVITY FIRE DEPARTMENT SPOTTER. WALL CLOUD STILL ROTATING ALTHOUGH CURRENTLY NO TORNADO.
May 11, 4:25 PM CDTTORNADO5 Sw Lenox, IABRIEF TWIN TORNADOES OCCURRED. LOCATION ESTIMATED. TRAINED SPOTTER LOOKING AT STORM FROM LENOX.
May 11, 4:40 PM CDTTORNADOLenox, IATAYLOR COUNTY EMERGENCY MANAGER REPORTS 20 SQUARE BLOCKS OF DAMAGE IN TOWN...EXTENT UNKNOWN AT THIS TIME.
May 11, 4:50 PM CDTTORNADOLenox, IAMULTIPLE TORNADOES IN AND AROUND LENOX. TORNADO DAMAGE ON THE WEST SIDE OF LENOX. HOMES AND TRAILERS DAMAGED AND POWER LINES DOWN.

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 11, 2:53 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.2 hours before the alert went out and 153 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 2011-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 909 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 2011-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939Sfc1 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
909 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
1123 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

017 
WFUS53 KDMX 112111
TORDMX
IAC003-173-112200-
/O.NEW.KDMX.TO.W.0033.110511T2111Z-110511T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
411 PM CDT WED MAY 11 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN ADAMS COUNTY IN SOUTHWEST IOWA...
  NORTH CENTRAL TAYLOR COUNTY IN SOUTHWEST IOWA...

* UNTIL 500 PM CDT

* AT 405 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 8 MILES NORTH OF BEDFORD...OR 19 MILES EAST OF
  CLARINDA...AND MOVING NORTH AT 10 MPH.

* LOCATIONS IMPACTED INCLUDE...
  LENOX AND SHARPSBURG.

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 4095 9471 4094 9449 4076 9460 4076 9473
TIME...MOT...LOC 2111Z 201DEG 9KT 4080 9466

$$

COGIL
5 follow-up statements
422 
WWUS53 KDMX 112119
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
419 PM CDT WED MAY 11 2011

IAC003-173-112200-
/O.CON.KDMX.TO.W.0033.000000T0000Z-110511T2200Z/
TAYLOR IA-ADAMS IA-
419 PM CDT WED MAY 11 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN ADAMS AND
NORTH CENTRAL TAYLOR COUNTIES UNTIL 500 PM CDT...

AT 415 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 7 MILES SOUTHWEST OF LENOX...OR 20 MILES EAST OF
CLARINDA...MOVING NORTH AT 10 MPH.

LOCATIONS IMPACTED INCLUDE...
  LENOX.

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 4079 9471 4095 9465 4094 9449 4076 9460
      4076 9461
TIME...MOT...LOC 2119Z 201DEG 9KT 4082 9465

$$

COGIL
116 
WWUS53 KDMX 112127
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
427 PM CDT WED MAY 11 2011

IAC003-173-112200-
/O.CON.KDMX.TO.W.0033.000000T0000Z-110511T2200Z/
TAYLOR IA-ADAMS IA-
427 PM CDT WED MAY 11 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN ADAMS AND
NORTH CENTRAL TAYLOR COUNTIES UNTIL 500 PM CDT...

AT 424 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO.  THIS 
TORNADO WAS LOCATED SOUTHWEST OF LENOX...OR 20 MILES SOUTHWEST OF 
CRESTON...MOVING NORTHEAST AT 15 MPH.

AT 422 PM...STORM SPOTTERS FROM THE GRAVITY FIRE DEPARTMENT REPORTED 
A BRIEF TORNADO NEAR SHARPSBURG.  THERE WERE NO REPORTS OF DAMAGE AS 
OF YET.

LOCATIONS IMPACTED INCLUDE...
  LENOX.

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 4082 9470 4095 9465 4094 9449 4078 9459
TIME...MOT...LOC 2127Z 214DEG 12KT 4085 9460

$$

COGIL
352 
WWUS53 KDMX 112136
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
436 PM CDT WED MAY 11 2011

IAC003-173-112200-
/O.CON.KDMX.TO.W.0033.000000T0000Z-110511T2200Z/
TAYLOR IA-ADAMS IA-
436 PM CDT WED MAY 11 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN ADAMS AND
NORTH CENTRAL TAYLOR COUNTIES UNTIL 500 PM CDT...

AT 433 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO.  THIS
TORNADO WAS LOCATED NEAR LENOX...OR 18 MILES SOUTHWEST OF CRESTON...
MOVING NORTHEAST AT 15 MPH.

AT 425 PM...TRAINED SPOTTERS REPORTED BRIEF TORNADO TOUCHDOWNS 5 
MILES SOUTHWEST OF LENOX.  ALTHOUGH THE SPOTTER REPORTED THE TORNADO 
HAD LIFTED TEMPORARILY...RADAR TRENDS INDICATE THE STORM 
STRENGTHENING AGAIN AND THE TORNADO POTENTIAL INCREASING AS IT MOVES 
TOWARD LENOX. 

LOCATIONS IMPACTED INCLUDE...
  LENOX.

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 4082 9470 4095 9465 4094 9449 4078 9459
TIME...MOT...LOC 2135Z 215DEG 14KT 4087 9457

$$

COGIL
255 
WWUS53 KDMX 112149
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
449 PM CDT WED MAY 11 2011

IAC003-173-112200-
/O.CON.KDMX.TO.W.0033.000000T0000Z-110511T2200Z/
TAYLOR IA-ADAMS IA-
449 PM CDT WED MAY 11 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN ADAMS AND
NORTHEASTERN TAYLOR COUNTIES UNTIL 500 PM CDT...

AT 447 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR LENOX...OR 15 MILES SOUTHWEST OF CRESTON...
MOVING NORTHEAST AT 15 MPH.

THIS STORM HAS HAD A HISTORY OF PRODUCING TORNADOES. 

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF EXTREME NORTHEASTERN TAYLOR AND EXTREME
  SOUTHEASTERN ADAMS COUNTIES.

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 4087 9462 4095 9461 4094 9449 4083 9456
TIME...MOT...LOC 2148Z 214DEG 11KT 4090 9455

$$

COGIL
613 
WWUS53 KDMX 112200
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
500 PM CDT WED MAY 11 2011

IAC003-173-112209-
/O.EXP.KDMX.TO.W.0033.000000T0000Z-110511T2200Z/
TAYLOR IA-ADAMS IA-
500 PM CDT WED MAY 11 2011

...THE TORNADO WARNING FOR SOUTHEASTERN ADAMS AND NORTHEASTERN TAYLOR
COUNTIES WILL EXPIRE AT 500 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WARNING REMAINS IN EFFECT FOR SOUTHEAST ADAMS AND SOUTHWEST UNION 
COUNTY UNTIL 530 PM CDT.

LAT...LON 4087 9462 4095 9461 4094 9449 4083 9456
TIME...MOT...LOC 2159Z 214DEG 11KT 4093 9453

$$

COGIL

The office that day

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

IssuedProductOfficeCountiesLasted
May 11, 12:43 PM CDTSevere Thunderstorm WarningDMXAdams, Cass47 min
May 11, 2:05 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor55 min
May 11, 2:22 PM CDTTornado WarningDMXAdams23 min
May 11, 2:43 PM CDTFlash Flood WarningDMXAdams, Taylor6 hr
May 11, 2:51 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor39 min
May 11, 4:01 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor44 min
May 11, 4:42 PM CDTFlash Flood WarningDMXAdams, Taylor6 hr
May 11, 4:50 PM CDTTornado WarningDMXAdams, Union40 min
May 11, 4:57 PM CDTSevere Thunderstorm WarningDMXAdams, Taylor38 min
May 11, 5:32 PM CDTSevere Thunderstorm WarningDMXAdams, Ringgold, Taylor, Union43 min
May 11, 5:42 PM CDTTornado WarningDMXUnion33 min
May 11, 5:44 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Madison, Ringgold, Warren46 min
May 11, 6:03 PM CDTFlash Flood WarningDMXUnion6 hr
May 11, 6:06 PM CDTSevere Thunderstorm WarningDMXAdair, Clarke, Madison, Union54 min
May 11, 6:37 PM CDTSevere Thunderstorm WarningDMXDallas, Madison, Polk, Warren53 min
May 11, 6:42 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Warren48 min
May 11, 6:46 PM CDTSevere Thunderstorm WarningDMXWayne44 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.