Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 37, NWS Des Moines, IA

May 22, 2011Black Hawk County, Bremer County, Iowa

NWS Des Moines, IA issued this tornado warning at May 22, 2011, 2:42 PM CDT for Black Hawk County, Bremer County, Iowa. It was in force for 33 min. 6 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 22, 2011, 2:42 PM CDT (19:42 UTC)
Expired
May 22, 2011, 3:15 PM CDT
In force
33 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon

Counties Black Hawk County, IA, Bremer County, IA

The radar

The La Crosse radar (KARX), 154 km from the middle of the area, began a volume at 19:43 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 22, 2:47 PM CDTFUNNEL CLOUD5 Nnw Cedar Falls, IATRAINED SPOTTER REPORTED FUNNEL CLOUD NORTHWEST OF CEDAR FALLS...
May 22, 2:50 PM CDTFUNNEL CLOUD2 S Waverly, IA
May 22, 2:50 PM CDTHAIL 1Tripoli, IA
May 22, 3:13 PM CDTFUNNEL CLOUD2 Se Tripoli, IAFUNNEL CLOUD REACHED ABOUT 3/4 OF THE WAY TO THE GROUND BEFORE RETREATING INTO THE WALL CLOUD.
May 22, 3:15 PM CDTHAIL 1Tripoli, IA
May 22, 3:25 PM CDTHAIL 2Sumner, IAUTILITY WORKERS REPORT. EAST SIDE OF SUMNER.

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 22, 12:51 PM CDTTornado WatchSPC10 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.7 hours before the alert went out and 195 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 12:00Z on 2011-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 233 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1775 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
233 m²/s²
0-3 km storm-relative helicity
287 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

005 
WFUS53 KDMX 221942
TORDMX
IAC013-017-222015-
/O.NEW.KDMX.TO.W.0037.110522T1942Z-110522T2015Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
242 PM CDT SUN MAY 22 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN BLACK HAWK COUNTY IN NORTHEAST IOWA...
  BREMER COUNTY IN NORTHEAST IOWA...

* UNTIL 315 PM CDT

* AT 238 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 6 MILES NORTHWEST OF CEDAR FALLS...OR 11 MILES
  NORTHWEST OF WATERLOO...AND MOVING NORTHEAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WAVERLY...DENVER...TRIPOLI...SUMNER...JANESVILLE...READLYN AND
  FREDERIKA.

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 4253 9253 4256 9256 4267 9255 4291 9231
      4291 9208 4290 9207 4275 9208
TIME...MOT...LOC 1942Z 226DEG 37KT 4261 9249

$$

COGIL
2 follow-up statements
748 
WWUS53 KDMX 221951
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
251 PM CDT SUN MAY 22 2011

IAC013-017-222015-
/O.CON.KDMX.TO.W.0037.000000T0000Z-110522T2015Z/
BLACK HAWK IA-BREMER IA-
251 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR BREMER AND NORTHWESTERN
BLACK HAWK COUNTIES UNTIL 315 PM CDT...

AT 246 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD.  A
TORNADO MAY DEVELOP AT ANY TIME. THIS DANGEROUS STORM WAS LOCATED 7
MILES SOUTH OF WAVERLY...OR 12 MILES NORTHWEST OF WATERLOO...MOVING
NORTHEAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE...
  WAVERLY...DENVER...TRIPOLI...SUMNER...READLYN AND FREDERIKA.

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 4257 9245 4259 9255 4267 9255 4291 9231
      4291 9208 4290 9207 4275 9208
TIME...MOT...LOC 1951Z 219DEG 38KT 4267 9245

$$

COGIL
385 
WWUS53 KDMX 222002
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
302 PM CDT SUN MAY 22 2011

IAC013-222012-
/O.CAN.KDMX.TO.W.0037.000000T0000Z-110522T2015Z/
BLACK HAWK IA-
302 PM CDT SUN MAY 22 2011

...THE TORNADO WARNING FOR NORTHWESTERN BLACK HAWK COUNTY IS
CANCELLED...

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

LAT...LON 4265 9229 4267 9242 4275 9245 4291 9231
      4291 9208 4290 9207 4275 9208
TIME...MOT...LOC 2002Z 226DEG 39KT 4274 9231

$$

IAC017-222015-
/O.CON.KDMX.TO.W.0037.000000T0000Z-110522T2015Z/
BREMER IA-
302 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR BREMER COUNTY UNTIL 315 PM
CDT...

AT 259 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR DENVER...OR 16 MILES NORTH OF WATERLOO...
MOVING NORTHEAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE...
  TRIPOLI...SUMNER...READLYN AND FREDERIKA.

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 4265 9229 4267 9242 4275 9245 4291 9231
      4291 9208 4290 9207 4275 9208
TIME...MOT...LOC 2002Z 226DEG 39KT 4274 9231

$$

COGIL

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 7:28 PM CDTSevere Thunderstorm WarningDMXEmmet32 min
May 21, 7:51 PM CDTSevere Thunderstorm WarningDMXAdair39 min
May 21, 7:57 PM CDTSevere Thunderstorm WarningDMXEmmet33 min
May 21, 8:21 PM CDTSevere Thunderstorm WarningDMXGuthrie24 min
May 21, 8:39 PM CDTSevere Thunderstorm WarningDMXDallas, Madison36 min
May 21, 8:41 PM CDTSevere Thunderstorm WarningDMXCrawford34 min
May 21, 8:59 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Warren, Wayne31 min
May 21, 9:03 PM CDTSevere Thunderstorm WarningDMXMadison, Warren27 min
May 21, 9:44 PM CDTSevere Thunderstorm WarningDMXAppanoose, Lucas, Monroe, Wayne31 min
May 21, 10:19 PM CDTSevere Thunderstorm WarningDMXMahaska, Poweshiek26 min
May 22, 9:19 AM CDTRiver Flood WarningDMXEmmet17 days
May 22, 9:19 AM CDTRiver Flood WarningDMXHumboldt11 days
May 22, 9:19 AM CDTRiver Flood WarningDMXHumboldt, Kossuth12 days
May 22, 1:38 PM CDTSevere Thunderstorm WarningDMXJasper, Poweshiek, Tama52 min
May 22, 2:02 PM CDTSevere Thunderstorm WarningDMXMahaska, Poweshiek43 min
May 22, 2:23 PM CDTTornado WarningDMXPoweshiek17 min
May 22, 2:29 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Bremer, Butler, Grundy46 min
May 22, 3:14 PM CDTTornado WarningDMXBremer31 min
May 22, 4:12 PM CDTSevere Thunderstorm WarningDMXAppanoose, Davis, Wapello27 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.