Alert archive / Iowa / Tornado Warnings in 2014

Tornado Warning 12, NWS Des Moines, IA

May 11, 2014Boone County, Hamilton County, Story County, Iowa

NWS Des Moines, IA issued this tornado warning at May 11, 2014, 10:47 PM CDT for Boone County, Hamilton County, Story 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: May 11, 2014, 10:47 PM CDT (03:47 UTC)
Expired: May 11, 2014, 11:15 PM CDT
In force: 28 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Boone County, IA, Hamilton County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 44 km from the middle of the area, began a volume at 03:49 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
May 11, 10:50 PM CDT	TSTM WND DMG	1 W Ames, IA	TREES DOWN ALONG FRANKLIN AVE ON THE WEST SIDE OF AMES. TIME ESTIMATED BY RADAR. VIA SOCIAL MEDIA.
May 11, 10:50 PM CDT	TSTM WND DMG	2 W Ames, IA	LARGE TREE LIMB DOWN. TIME ESTIMATED BY RADAR.
May 11, 10:51 PM CDT	TSTM WND DMG	2 Wnw Ames, IA	2 TO 4 INCH TREE LIMBS DOWN. LEE PARK. TIME ESTIMATED BY RADAR.

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
May 11, 7:49 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 3.8 hours before the alert went out and 248 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: 2520 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 967 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 274 m²/s²
0-3 km storm-relative helicity: 254 m²/s²
Significant tornado parameter: 4.5
Supercell composite: 18.8

Open this sounding in Storm Lab

The text

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

798 
WFUS53 KDMX 120347
TORDMX
IAC015-079-169-120415-
/O.NEW.KDMX.TO.W.0012.140512T0347Z-140512T0415Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1047 PM CDT SUN MAY 11 2014

THE NATIONAL WEATHER SERVICE IN DES MOINES  HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN BOONE COUNTY IN CENTRAL IOWA...
  NORTHWESTERN STORY COUNTY IN CENTRAL IOWA...
  SOUTHEASTERN HAMILTON COUNTY IN CENTRAL IOWA...

* UNTIL 1115 PM CDT
    
* AT 1046 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED NEAR IOWA STATE CENTER...OR 7 MILES SOUTHWEST
  OF AMES...MOVING NORTHEAST AT 45 MPH.

  HAZARD...TORNADO...QUARTER SIZE HAIL AND 60 MPH WIND GUSTS. 

  SOURCE...RADAR INDICATED ROTATION. 

  IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
           SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. 
           DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE 
           DAMAGE IS LIKELY. 

* THIS DANGEROUS STORM WILL BE NEAR...
  IOWA STATE CENTER AROUND 1055 PM CDT.
  AMES AND GILBERT AROUND 1100 PM CDT.
  STORY CITY AND ROLAND AROUND 1110 PM CDT.

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE AMES
MUNICIPAL AIRPORT...LUTHER...RANDALL...MCCALLSBURG AND KELLEY.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 112 AND 130.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 4189 9371 4195 9384 4232 9367 4222 9346
      4221 9346 4221 9343 4218 9336
TIME...MOT...LOC 0346Z 211DEG 41KT 4198 9375 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

SMALL

2 follow-up statements

951 
WWUS53 KDMX 120402
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1102 PM CDT SUN MAY 11 2014

IAC015-120412-
/O.CAN.KDMX.TO.W.0012.000000T0000Z-140512T0415Z/
BOONE IA-

1102 PM CDT SUN MAY 11 2014

...THE TORNADO WARNING FOR EASTERN BOONE COUNTY IS CANCELLED...
    
THE TORNADIC THUNDERSTORM WHICH PROMPTED THE WARNING HAS MOVED OUT 
OF THE WARNED AREA. THEREFORE THE WARNING HAS BEEN CANCELLED.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 300 AM CDT MONDAY MORNING FOR
IOWA.

LAT...LON 4202 9363 4206 9370 4208 9370 4230 9362
      4222 9346 4221 9346 4221 9343 4218 9336
TIME...MOT...LOC 0402Z 212DEG 39KT 4211 9362 

$$

IAC079-169-120415-
/O.CON.KDMX.TO.W.0012.000000T0000Z-140512T0415Z/
STORY IA-HAMILTON IA-
1102 PM CDT SUN MAY 11 2014

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT FOR
NORTHWESTERN STORY AND SOUTHEASTERN HAMILTON COUNTIES...
    
AT 1102 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED OVER GILBERT...OR NEAR AMES...MOVING NORTHEAST AT 45 MPH.

HAZARD...TORNADO. 

SOURCE...RADAR INDICATED ROTATION. 

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
         SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE 
         TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE DAMAGE IS 
         LIKELY. 

THIS DANGEROUS STORM WILL BE NEAR...
  ROLAND AROUND 1110 PM CDT.

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
RANDALL AND MCCALLSBURG.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 117 AND 130.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A BASEMENT OR 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.

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 4202 9363 4206 9370 4208 9370 4230 9362
      4222 9346 4221 9346 4221 9343 4218 9336
TIME...MOT...LOC 0402Z 212DEG 39KT 4211 9362 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

SMALL

178 
WWUS53 KDMX 120411
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1111 PM CDT SUN MAY 11 2014

IAC079-169-120420-
/O.EXP.KDMX.TO.W.0012.000000T0000Z-140512T0415Z/
STORY IA-HAMILTON IA-
1111 PM CDT SUN MAY 11 2014

...THE TORNADO WARNING FOR NORTHWESTERN STORY AND SOUTHEASTERN
HAMILTON COUNTIES WILL EXPIRE AT 1115 PM CDT...
                
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER APPEARS CAPABLE OF PRODUCING A TORNADO. 
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.  HOWEVER STRONG 
GUSTY WINDS AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS THUNDERSTORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 300 AM CDT MONDAY MORNING FOR
IOWA.

REMEMBER...A SEVERE THUNDERSTORM WARNING STILL REMAINS IN EFFECT FOR 
THE AREA UNTIL MIDNIGHT.

LAT...LON 4202 9363 4206 9370 4208 9370 4230 9362
      4222 9346 4221 9346 4221 9343 4218 9336
TIME...MOT...LOC 0407Z 211DEG 41KT 4211 9362 

$$

SMALL

The office that day

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

Issued	Product	Office	Counties	Lasted
May 11, 7:58 PM CDT	Special Weather Statement	DMX	Adair, Audubon, Carroll, Cass, Crawford, Guthrie	2 hr
May 11, 8:08 PM CDT	Severe Thunderstorm Warning	DMX	Emmet, Kossuth	37 min
May 11, 8:24 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll, Cass, Crawford	66 min
May 11, 9:05 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Cass	40 min
May 11, 9:15 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Carroll, Crawford, Greene, Sac	45 min
May 11, 9:21 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Audubon, Carroll, Dallas, Greene, Guthrie	39 min
May 11, 9:30 PM CDT	Flash Flood Warning	DMX	Audubon, Carroll, Cass, Crawford	6 hr
May 11, 9:45 PM CDT	Tornado Warning	DMX	Dallas, Guthrie	30 min
May 11, 9:59 PM CDT	Tornado Warning	DMX	Boone, Dallas, Greene, Guthrie	46 min
May 11, 10:03 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Boone, Dallas, Greene, Guthrie, Hamilton and 6 more	57 min
May 11, 10:26 PM CDT	Tornado Warning	DMX	Dallas, Polk, Story	34 min
May 11, 10:45 PM CDT	Severe Thunderstorm Warning	DMX	Adams, Cass	45 min
May 11, 10:55 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Hamilton, Hardin, Jasper, Marion, Marshall and 3 more	65 min
May 11, 11:13 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Cass, Union	47 min
May 12, 12:31 AM CDT	Flash Flood Warning	DMX	Adair	6 hr
May 12, 12:47 AM CDT	Severe Thunderstorm Warning	DMX	Clarke, Ringgold, Union	43 min
May 12, 1:32 AM CDT	Severe Thunderstorm Warning	DMX	Clarke, Lucas, Marion, Warren	43 min
May 12, 3:05 AM CDT	Special Weather Statement	DMX	Carroll	25 min
May 12, 4:45 AM CDT	Special Weather Statement	DMX	Hardin	30 min
May 12, 9:34 AM CDT	Special Weather Statement	DMX	Mahaska, Monroe, Wayne	56 min
May 12, 10:34 AM CDT	Flash Flood Watch	DMX	Appanoose, Black Hawk, Bremer, Butler, Clarke, Davis and 14 more	7 hr
May 12, 1:39 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Ringgold, Wayne	36 min
May 12, 2:47 PM CDT	Flash Flood Warning	DMX	Lucas	6 hr
May 12, 3:14 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Marion, Monroe, Poweshiek, Wapello	46 min
May 12, 3:36 PM CDT	Severe Thunderstorm Warning	DMX	Davis	39 min
May 12, 4:18 PM CDT	Flash Flood Warning	DMX	Marion, Monroe	6 hr

Nearby

Tornado Warnings in Iowa, 2014 Every tornado warning in 2014 Tornadoes in 2014

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.