Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 53, NWS Des Moines, IA

July 11, 2011Marshall County, Tama County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 11, 2011, 4:32 AM CDT for Marshall County, Tama County, Iowa. It was in force for 28 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: Jul 11, 2011, 4:32 AM CDT (09:32 UTC)
Expired: Jul 11, 2011, 5:00 AM CDT
In force: 28 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon

Counties Marshall County, IA, Tama County, IA

The radar

The Des Moines radar (KDMX), 105 km from the middle of the area, began a volume at 09:32 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

Time	Report	Where	Remark
Jul 11, 4:35 AM CDT	TSTM WND DMG	Gladbrook, IA	NUMEROUS TREES DOWN. NO ELECTRICITY IN NEIGHBORHOOD. TIME ESTIMATED FROM RADAR. REPORT RELAYED BY KWWL TV.
Jul 11, 4:40 AM CDT	TSTM WND DMG	Dysart, IA	NUMEROUS TREES DOWN...WINDOWS BROKE OUT AND RESCUE CREWS CALLED OUT. TIME ESTIMATED FROM RADAR. REPORT RELAYED BY KWWL TV.
Jul 11, 4:41 AM CDT	TSTM WND DMG	Dysart, IA	TREES LIMBS DOWN AND POWER OUT. SWING SET WRAPPED AROUND A TREE.

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.

Issued	Product	Office	Lasted
Jul 11, 1:21 AM CDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 9.5 hours before the alert went out and 187 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3733 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 850 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 84 m²/s²
0-3 km storm-relative helicity: 165 m²/s²
Significant tornado parameter: 3.4
Supercell composite: 14.3

Open this sounding in Storm Lab

The text

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

127 
WFUS53 KDMX 110932
TORDMX
IAC127-171-111000-
/O.NEW.KDMX.TO.W.0053.110711T0932Z-110711T1000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
432 AM CDT MON JUL 11 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN MARSHALL COUNTY IN CENTRAL IOWA...
  NORTHERN TAMA COUNTY IN CENTRAL IOWA...

* UNTIL 500 AM CDT

* AT 427 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 7 MILES SOUTHEAST OF CONRAD...OR 9 MILES
  NORTHEAST OF MARSHALLTOWN...AND MOVING EAST AT 55 MPH.

* LOCATIONS IMPACTED INCLUDE...
  DYSART AND TRAER.

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.

TORNADOES ARE DIFFICULT TO SEE AT NIGHT...ACT QUICKLY. TAKE COVER
NOW!

&&

LAT...LON 4214 9229 4201 9279 4220 9286 4221 9285
      4221 9283 4221 9277 4223 9276 4230 9248
      4229 9229
TIME...MOT...LOC 0932Z 251DEG 48KT 4216 9270

$$

DONAVON

2 follow-up statements

245 
WWUS53 KDMX 110941
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
441 AM CDT MON JUL 11 2011

IAC127-110951-
/O.CAN.KDMX.TO.W.0053.000000T0000Z-110711T1000Z/
MARSHALL IA-
441 AM CDT MON JUL 11 2011

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

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

LAT...LON 4202 9277 4221 9277 4223 9276 4230 9248
      4229 9229 4214 9229
TIME...MOT...LOC 0941Z 252DEG 95KT 4223 9239

$$

IAC171-111000-
/O.CON.KDMX.TO.W.0053.000000T0000Z-110711T1000Z/
TAMA IA-
441 AM CDT MON JUL 11 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHERN TAMA COUNTY UNTIL
500 AM CDT...

AT 436 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 9 MILES SOUTH OF REINBECK...OR 21 MILES NORTHEAST
OF MARSHALLTOWN...MOVING EAST AT 110 MPH.

LOCATIONS IMPACTED INCLUDE...
  DYSART.

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.

TORNADOES ARE DIFFICULT TO SEE AT NIGHT...ACT QUICKLY. TAKE COVER
NOW.

&&

LAT...LON 4202 9277 4221 9277 4223 9276 4230 9248
      4229 9229 4214 9229
TIME...MOT...LOC 0941Z 252DEG 95KT 4223 9239

$$

DONAVON

509 
WWUS53 KDMX 110955
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
455 AM CDT MON JUL 11 2011

IAC171-111006-
/O.EXP.KDMX.TO.W.0053.000000T0000Z-110711T1000Z/
TAMA IA-
455 AM CDT MON JUL 11 2011

...THE TORNADO WARNING FOR NORTHERN TAMA COUNTY WILL EXPIRE AT 500 AM
CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 8 AM.

LAT...LON 4202 9277 4221 9277 4223 9276 4230 9248
      4229 9229 4214 9229
TIME...MOT...LOC 0956Z 252DEG 95KT 4234 9187

$$

DONAVON

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 1:12 AM CDT	Severe Thunderstorm Warning	DMX	Emmet, Kossuth, Palo Alto	48 min
Jul 11, 2:10 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Audubon, Cass, Guthrie	50 min
Jul 11, 2:24 AM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Hancock, Winnebago, Worth	51 min
Jul 11, 2:41 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Dallas, Guthrie, Madison, Polk, Warren	49 min
Jul 11, 2:52 AM CDT	Severe Thunderstorm Warning	DMX	Hamilton, Humboldt, Webster, Wright	38 min
Jul 11, 3:25 AM CDT	Severe Thunderstorm Warning	DMX	Boone, Marshall, Story	50 min
Jul 11, 3:34 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion, Marshall, Polk, Story, Warren	41 min
Jul 11, 3:53 AM CDT	Tornado Warning	DMX	Marshall, Story	37 min
Jul 11, 4:02 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Poweshiek, Tama	43 min
Jul 11, 4:18 AM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Tama	42 min
Jul 11, 4:57 AM CDT	Severe Thunderstorm Warning	DMX	Black Hawk	18 min

Nearby

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