Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 23, NWS Omaha, NE

June 26, 2011Harrison County, Monona County, Iowa

NWS Omaha, NE issued this tornado warning at Jun 26, 2011, 7:54 PM CDT for Harrison County, Monona County, Iowa. It was in force for 23 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 26, 2011, 7:54 PM CDT (00:54 UTC)
Expired
Jun 26, 2011, 8:17 PM CDT
In force
23 min
Issued by
NWS Omaha, NE
Area
Storm-based polygon

Counties Harrison County, IA, Monona County, IA

The radar

The Omaha radar (KOAX), 75 km from the middle of the area, began a volume at 00:54 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 26, 4:56 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.9 hours before the alert went out and 75 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 00:00Z on 2011-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2873 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 00:00Z on 2011-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 248 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
2873 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
501 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
248 m²/s²
0-3 km storm-relative helicity
308 m²/s²
Significant tornado parameter
6.2
Supercell composite
26.5

Open this sounding in Storm Lab

The text

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

722 
WFUS53 KOAX 270054
TOROAX
IAC085-133-270130-
/O.NEW.KOAX.TO.W.0023.110627T0054Z-110627T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
754 PM CDT SUN JUN 26 2011

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN HARRISON COUNTY IN SOUTHWEST IOWA...
  SOUTHEASTERN MONONA COUNTY IN WEST CENTRAL IOWA...

* UNTIL 830 PM CDT

* AT 750 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR PISGAH...OR 40 MILES NORTH OF OMAHA...AND
  MOVING EAST AT 40 MPH.

* LOCATIONS IMPACTED INCLUDE...
  PREPARATION CANYON STATE PARK AND DUNLAP.

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 4179 9605 4192 9600 4192 9567 4187 9567
      4186 9556 4174 9556
TIME...MOT...LOC 0055Z 274DEG 37KT 4185 9593

$$

CHERMOK
3 follow-up statements
657 
WWUS53 KOAX 270101
SVSOAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
801 PM CDT SUN JUN 26 2011

IAC085-133-270130-
/O.CON.KOAX.TO.W.0023.000000T0000Z-110627T0130Z/
MONONA IA-HARRISON IA-
801 PM CDT SUN JUN 26 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN HARRISON AND
SOUTHEASTERN MONONA COUNTIES UNTIL 830 PM CDT...

AT 759 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
DANGEROUS STORM WAS LOCATED 6 MILES EAST OF PISGAH...OR 40 MILES
NORTH OF OMAHA...MOVING EAST AT 60 MPH.

LOCATIONS IMPACTED INCLUDE...
  DUNLAP.

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 4178 9589 4190 9585 4192 9567 4187 9567
      4186 9556 4174 9556
TIME...MOT...LOC 0102Z 275DEG 54KT 4182 9576

$$

CHERMOK/MAYES
996 
WWUS53 KOAX 270108
SVSOAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
808 PM CDT SUN JUN 26 2011

IAC133-270119-
/O.CAN.KOAX.TO.W.0023.000000T0000Z-110627T0130Z/
MONONA IA-
808 PM CDT SUN JUN 26 2011

...THE TORNADO WARNING FOR SOUTHEASTERN MONONA COUNTY IS CANCELLED...

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

LAT...LON 4177 9578 4186 9575 4186 9556 4174 9556
TIME...MOT...LOC 0109Z 275DEG 54KT 4181 9562

$$

IAC085-270130-
/O.CON.KOAX.TO.W.0023.000000T0000Z-110627T0130Z/
HARRISON IA-
808 PM CDT SUN JUN 26 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN HARRISON
COUNTY UNTIL 830 PM CDT...

AT 804 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
DANGEROUS STORM WAS LOCATED 10 MILES SOUTHEAST OF MOORHEAD...OR 41
MILES NORTH OF OMAHA...MOVING EAST AT 60 MPH.

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF NORTHEASTERN HARRISON COUNTY.

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 4177 9578 4186 9575 4186 9556 4174 9556
TIME...MOT...LOC 0109Z 275DEG 54KT 4181 9562

$$

CHERMOK/MAYES
355 
WWUS53 KOAX 270117
SVSOAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
817 PM CDT SUN JUN 26 2011

IAC085-270127-
/O.CAN.KOAX.TO.W.0023.000000T0000Z-110627T0130Z/
HARRISON IA-
817 PM CDT SUN JUN 26 2011

...THE TORNADO WARNING FOR NORTHEASTERN HARRISON COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND MOVED OUT OF
THE WARNED AREA.  HOWEVER GUSTY WINDS ARE STILL POSSIBLE WITH THIS
THUNDERSTORM.

REMEMBER...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR 
EASTERN HARRISON COUNTY UNTIL 845 PM.

LAT...LON 4177 9578 4186 9575 4186 9556 4174 9556
TIME...MOT...LOC 0117Z 275DEG 54KT 4180 9546

$$

CHERMOK/MAYES

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 7:22 PM CDTSevere Thunderstorm WarningOAXMonona53 min
Jun 26, 7:33 PM CDTSevere Thunderstorm WarningOAXHarrison, Monona, Pottawattamie, Shelby42 min
Jun 26, 8:07 PM CDTSevere Thunderstorm WarningOAXHarrison, Monona, Pottawattamie, Shelby38 min
Jun 26, 8:22 PM CDTSevere Thunderstorm WarningOAXMills, Pottawattamie38 min
Jun 26, 8:33 PM CDTSevere Thunderstorm WarningOAXMills, Pottawattamie42 min
Jun 26, 8:41 PM CDTSevere Thunderstorm WarningOAXMills, Montgomery, Pottawattamie, Shelby49 min
Jun 26, 8:45 PM CDTAreal Flood AdvisoryOAXHarrison, Monona, Pottawattamie, Shelby3 hr
Jun 26, 8:53 PM CDTSevere Thunderstorm WarningOAXFremont, Mills, Montgomery52 min
Jun 26, 9:08 PM CDTAreal Flood AdvisoryOAXFremont, Harrison, Mills, Montgomery, Pottawattamie, Shelby2 hr
Jun 26, 9:31 PM CDTSevere Thunderstorm WarningOAXFremont, Mills, Montgomery, Page44 min
Jun 26, 10:01 PM CDTAreal Flood AdvisoryOAXFremont, Montgomery, Page86 min
Jun 27, 12:30 AM CDTRiver Flood WarningOAXPage14 hr
Jun 27, 12:49 AM CDTSevere Thunderstorm WarningOAXFremont, Page56 min
Jun 27, 1:25 AM CDTRiver Flood WarningOAXFremont38 hr
Jun 27, 1:25 AM CDTRiver Flood WarningOAXFremont5 hr
Jun 27, 2:15 AM CDTSevere Thunderstorm WarningOAXFremont, Mills45 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.