Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 57, NWS Des Moines, IA

August 6, 2011Lucas County, Marion County, Monroe County, Iowa

NWS Des Moines, IA issued this tornado warning at Aug 6, 2011, 11:36 PM CDT for Lucas County, Marion County, Monroe County, Iowa. It was in force for 24 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: Aug 6, 2011, 11:36 PM CDT (04:36 UTC)
Expired: Aug 7, 2011, 12:00 AM CDT
In force: 24 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon

Counties Lucas County, IA, Marion County, IA, Monroe County, IA

The radar

The Des Moines radar (KDMX), 87 km from the middle of the area, began a volume at 04:37 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
Aug 6, 11:50 PM CDT	TSTM WND DMG	Williamson, IA	CAMPER BLOWN OFF ITS JACKS

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
Aug 6, 10:14 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.6 hours before the alert went out and 221 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: 1118 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 1057 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 5.1

Open this sounding in Storm Lab

The text

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

594 
WFUS53 KDMX 070436
TORDMX
IAC117-125-135-070515-
/O.NEW.KDMX.TO.W.0057.110807T0436Z-110807T0515Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1136 PM CDT SAT AUG 6 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN LUCAS COUNTY IN SOUTH CENTRAL IOWA...
  SOUTHEASTERN MARION COUNTY IN SOUTH CENTRAL IOWA...
  NORTHWESTERN MONROE COUNTY IN SOUTH CENTRAL IOWA...

* UNTIL 1215 AM CDT

* AT 1132 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 8 MILES EAST OF CHARITON...OR 27 MILES NORTHWEST
  OF CENTERVILLE...AND MOVING NORTHEAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  MARYSVILLE...LOVILIA...HAMILTON AND BUSSEY.

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 4126 9289 4108 9286 4094 9329 4109 9337
TIME...MOT...LOC 0436Z 245DEG 39KT 4108 9312

$$

VACHALEK

2 follow-up statements

670 
WWUS53 KDMX 070449
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1149 PM CDT SAT AUG 6 2011

IAC117-070459-
/O.CAN.KDMX.TO.W.0057.000000T0000Z-110807T0515Z/
LUCAS IA-
1149 PM CDT SAT AUG 6 2011

...THE TORNADO WARNING FOR EASTERN LUCAS COUNTY IS CANCELLED...

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

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN DES MOINES.

LAT...LON 4109 9310 4110 9310 4116 9310 4116 9317
      4126 9289 4108 9286 4100 9310
TIME...MOT...LOC 0449Z 262DEG 34KT 4107 9288

$$

IAC125-135-070515-
/O.CON.KDMX.TO.W.0057.000000T0000Z-110807T0515Z/
MONROE IA-MARION IA-
1149 PM CDT SAT AUG 6 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN MARION AND
NORTHWESTERN MONROE COUNTIES UNTIL 1215 AM CDT...

AT 1146 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 ALBIA...OR 21 MILES SOUTHWEST
OF OSKALOOSA...MOVING EAST AT 40 MPH.

LOCATIONS IMPACTED INCLUDE...
  BUSSEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN DES MOINES.

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

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

&&

LAT...LON 4109 9310 4110 9310 4116 9310 4116 9317
      4126 9289 4108 9286 4100 9310
TIME...MOT...LOC 0449Z 262DEG 34KT 4107 9288

$$

VACHALEK

032 
WWUS53 KDMX 070500
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1200 AM CDT SUN AUG 7 2011

IAC125-135-070509-
/O.CAN.KDMX.TO.W.0057.000000T0000Z-110807T0515Z/
MONROE IA-MARION IA-
1200 AM CDT SUN AUG 7 2011

...THE TORNADO WARNING FOR SOUTHEASTERN MARION AND NORTHWESTERN
MONROE COUNTIES IS CANCELLED...

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

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 5 AM CDT SUNDAY.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN DES MOINES.

REMEMBER...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR THE 
WARNED AREA AS WELL UNTIL 1215 AM CDT SUNDAY MORNING.

LAT...LON 4109 9310 4110 9310 4116 9310 4116 9317
      4126 9289 4108 9286 4100 9310
TIME...MOT...LOC 0459Z 262DEG 34KT 4099 9274

$$

VACHALEK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 7:34 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	26 min
Aug 6, 7:57 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll, Crawford	48 min
Aug 6, 8:32 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass, Guthrie	43 min
Aug 6, 9:08 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Audubon, Cass, Guthrie	52 min
Aug 6, 9:26 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Cass, Ringgold, Taylor, Union	49 min
Aug 6, 9:41 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Audubon, Cass	49 min
Aug 6, 9:58 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Guthrie, Madison	47 min
Aug 6, 10:16 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Madison, Ringgold, Taylor, Union	44 min
Aug 6, 10:30 PM CDT	Tornado Warning	DMX	Adair, Madison	28 min
Aug 6, 10:45 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur	45 min
Aug 6, 10:46 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Madison, Warren	29 min
Aug 6, 11:08 PM CDT	Severe Thunderstorm Warning	DMX	Lucas, Wayne	52 min
Aug 6, 11:09 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Jasper, Lucas, Madison, Marion, Polk and 1 more	51 min
Aug 6, 11:32 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Monroe	43 min
Aug 6, 11:48 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion, Poweshiek	57 min
Aug 7, 12:02 AM CDT	Severe Thunderstorm Warning	DMX	Davis, Wapello	58 min
Aug 7, 3:19 AM CDT	Severe Thunderstorm Warning	DMX	Butler, Franklin	41 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.