Alert archive / Iowa / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 13, NWS Des Moines, IA

April 13, 20184 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 13, 2018, 8:19 PM CDT for 4 counties in Iowa. It was in force for 41 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: Apr 13, 2018, 8:19 PM CDT (01:19 UTC)
Expired: Apr 13, 2018, 9:00 PM CDT
In force: 41 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Butler County, IA, Cerro Gordo County, IA, Franklin County, IA, Grundy County, IA

The radar

The Des Moines radar (KDMX), 122 km from the middle of the area, began a volume at 01:19 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.

Issued	Product	Office	Lasted
Apr 13, 3:22 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.3 hours before the alert went out and 234 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 834 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 524 m²/s²
0-3 km storm-relative helicity: 713 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

831 
WUUS53 KDMX 140119
SVRDMX
IAC023-033-069-075-140200-
/O.NEW.KDMX.SV.W.0013.180414T0119Z-180414T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
819 PM CDT FRI APR 13 2018

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Eastern Franklin County in north central Iowa...
  Northwestern Grundy County in central Iowa...
  Butler County in north central Iowa...
  Southeastern Cerro Gordo County in north central Iowa...

* Until 900 PM CDT.

* At 819 PM CDT, severe thunderstorms were located along a line
  extending from 7 miles west of Sheffield to 6 miles southeast of
  Hampton to near Eldora, moving northeast at 40 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Trained weather spotters. At 815 pm...a 59 mph wind gust 
           was reported at the Iowa Falls Airport.  

  IMPACT...Expect damage to roofs, siding, and trees. 

* Locations impacted include...
  Hampton, Allison, Parkersburg, Ackley, Clarksville, Shell Rock,
  Sheffield, Greene, Aplington, Rockwell, Wellsburg, Dumont, New
  Hartford, Stout, Geneva, Bristow, Hansell, Chapin, Aredale and
  Dougherty.

This includes Interstate 35 between mile markers 173 and 176.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4238 9300 4247 9300 4247 9303 4256 9303
      4256 9311 4264 9314 4287 9339 4314 9302
      4291 9302 4291 9259 4283 9255 4260 9255
TIME...MOT...LOC 0119Z 223DEG 33KT 4288 9336 4266 9315 4241 9303 

HAIL...<.75IN
WIND...60MPH
 
$$

MF

3 follow-up statements

442 
WWUS53 KDMX 140135 RRA
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
835 PM CDT FRI APR 13 2018

IAC075-140145-
/O.CAN.KDMX.SV.W.0013.000000T0000Z-180414T0200Z/
Grundy IA-
835 PM CDT FRI APR 13 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN GRUNDY COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of
the warned area. Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until 900 PM CDT for
northeastern Iowa.

LAT...LON 4256 9303 4261 9301 4267 9306 4288 9336
      4314 9302 4291 9302 4291 9259 4283 9255
      4260 9255 4256 9263
TIME...MOT...LOC 0135Z 230DEG 44KT 4297 9318 4278 9294 4255 9284 

$$

IAC023-033-069-140200-
/O.CON.KDMX.SV.W.0013.000000T0000Z-180414T0200Z/
Franklin IA-Butler IA-Cerro Gordo IA-
835 PM CDT FRI APR 13 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM CDT
FOR NORTHEASTERN FRANKLIN...BUTLER AND SOUTHEASTERN CERRO GORDO
COUNTIES...

At 835 PM CDT, severe thunderstorms were located along a line
extending from Rockwell to 7 miles west of Allison to near Aplington,
moving northeast at 50 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Trained weather spotters. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Allison, Parkersburg, Clarksville, Shell Rock, Sheffield, Greene,
Aplington, Rockwell, Dumont, New Hartford, Bristow, Hansell, Chapin,
Aredale, Dougherty and Allison Municipal Airport.

This includes Interstate 35 near mile marker 176.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4256 9303 4261 9301 4267 9306 4288 9336
      4314 9302 4291 9302 4291 9259 4283 9255
      4260 9255 4256 9263
TIME...MOT...LOC 0135Z 230DEG 44KT 4297 9318 4278 9294 4255 9284 

HAIL...<.75IN
WIND...60MPH
 
$$

MF

810 
WWUS53 KDMX 140144
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
844 PM CDT FRI APR 13 2018

IAC023-033-069-140200-
/O.CON.KDMX.SV.W.0013.000000T0000Z-180414T0200Z/
Franklin IA-Butler IA-Cerro Gordo IA-
844 PM CDT FRI APR 13 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM CDT
FOR NORTHEASTERN FRANKLIN...NORTHERN BUTLER AND SOUTHEASTERN CERRO
GORDO COUNTIES...

At 844 PM CDT, severe thunderstorms were located along a line
extending from near Rockwell to near Greene to near Clarksville,
moving northeast at 40 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Allison, Clarksville, Shell Rock, Greene, Rockwell, Bristow, Aredale,
Dougherty and Allison Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4266 9274 4267 9286 4277 9296 4297 9323
      4314 9302 4291 9302 4291 9259 4283 9255
      4271 9255 4266 9260
TIME...MOT...LOC 0144Z 222DEG 33KT 4303 9311 4284 9287 4272 9268 

HAIL...<.75IN
WIND...60MPH
 
$$

MF

199 
WWUS53 KDMX 140155
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
855 PM CDT FRI APR 13 2018

IAC023-033-069-140205-
/O.EXP.KDMX.SV.W.0013.000000T0000Z-180414T0200Z/
Franklin IA-Butler IA-Cerro Gordo IA-
855 PM CDT FRI APR 13 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN FRANKLIN...
NORTHERN BUTLER AND SOUTHEASTERN CERRO GORDO COUNTIES WILL EXPIRE AT
900 PM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore the warning will be allowed to expire.  However gusty winds
and heavy rain are still possible with these thunderstorms.

LAT...LON 4266 9274 4267 9286 4277 9296 4297 9323
      4314 9302 4291 9302 4291 9259 4283 9255
      4271 9255 4266 9260
TIME...MOT...LOC 0155Z 223DEG 33KT 4310 9302 4291 9278 4279 9259 

$$

MF

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 13, 7:05 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Cass	40 min
Apr 13, 7:18 PM CDT	Severe Thunderstorm Warning	DMX	Adams, Taylor	42 min
Apr 13, 7:23 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Hamilton, Hardin, Marshall, Story	52 min
Apr 13, 7:49 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Madison, Union	41 min
Apr 13, 7:52 PM CDT	Severe Thunderstorm Warning	DMX	Franklin, Hamilton, Hardin, Marshall, Story, Wright	39 min
Apr 13, 7:59 PM CDT	Severe Thunderstorm Warning	DMX	Adams, Ringgold, Taylor, Union	36 min
Apr 13, 8:32 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Madison, Union	37 min
Apr 13, 8:43 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Polk	36 min
Apr 14, 1:31 AM CDT	Wind Advisory	DMX	Black Hawk, Bremer, Butler, Dallas, Grundy, Hardin and 6 more	14 hr
Apr 14, 6:52 AM CDT	River Flood Warning	DMX	Cerro Gordo, Floyd, Worth	11 hr
Apr 14, 10:42 AM CDT	River Flood Warning	DMX	Black Hawk	12 days

Nearby

Severe Thunderstorm Warnings in Iowa, 2018 Every severe thunderstorm warning in 2018

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.