Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 78, NWS Des Moines, IA

May 6, 2012Dallas County, Polk County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 6, 2012, 7:59 AM CDT for Dallas County, Polk County, Iowa. It was in force for 46 min. 2 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 6, 2012, 7:59 AM CDT (12:59 UTC)
Expired: May 6, 2012, 8:45 AM CDT
In force: 46 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Dallas County, IA, Polk County, IA

The radar

The Des Moines radar (KDMX), 5 km from the middle of the area, began a volume at 13:00 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 6, 8:32 AM CDT	TSTM WND GST 71	4 Ene Dallas Center, IA	DELAYED REPORT CORRECTED
May 6, 8:32 AM CDT	NON-TSTM WND GST 71	4 Ene Dallas Center, IA	DELAYED REPORT

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 6, 7:17 AM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 1.0 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 880 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: -415 m²/s²
0-3 km storm-relative helicity: -233 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

411 
WUUS53 KDMX 061259
SVRDMX
IAC049-153-061345-
/O.NEW.KDMX.SV.W.0078.120506T1259Z-120506T1345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
759 AM CDT SUN MAY 6 2012

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN DALLAS COUNTY IN CENTRAL IOWA...
  POLK COUNTY IN CENTRAL IOWA...

* UNTIL 845 AM CDT

* AT 756 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  DALLAS CENTER...OR 23 MILES WEST OF DES MOINES...AND MOVING EAST AT
  40 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WAUKEE...WOODWARD...GRIMES...CLIVE...URBANDALE...WINDSOR HEIGHTS...
  JOHNSTON...POLK CITY...ANKENY...ALTOONA...BONDURANT...GRANGER...
  SAYLORVILLE LAKE...SAYLORVILLE...ALLEMAN...ANKENY AIRPORT...ELKHART
  AND MITCHELLVILLE.

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 112 AND 149.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 72 AND 102.

THIS INCLUDES INTERSTATE 235 BETWEEN MILE MARKERS 1 AND 14.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO AN INTERIOR ROOM AND STAY AWAY FROM WINDOWS. IF YOU ARE IN A
MOBILE HOME...GET OUT NOW...AND SEEK SHELTER IN A REINFORCED
BUILDING.

&&

LAT...LON 4153 9397 4183 9415 4186 9384 4186 9335
      4166 9335
TIME...MOT...LOC 1300Z 258DEG 33KT 4169 9399
WIND...HAIL 60MPH 1.00IN

$$

ZOGG

2 follow-up statements

906 
WWUS53 KDMX 061328
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
828 AM CDT SUN MAY 6 2012

IAC049-153-061345-
/O.CON.KDMX.SV.W.0078.000000T0000Z-120506T1345Z/
POLK IA-DALLAS IA-
828 AM CDT SUN MAY 6 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHEASTERN
DALLAS AND POLK COUNTIES UNTIL 845 AM CDT...

AT 823 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR POLK
CITY...OR 12 MILES NORTHWEST OF DES MOINES...MOVING EAST AT 40 MPH.

LOCATIONS IMPACTED INCLUDE...
  ANKENY...ALTOONA...BONDURANT...ALLEMAN...ANKENY AIRPORT...ELKHART
  AND MITCHELLVILLE.

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 122 AND 149.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 72 AND 102.

THIS INCLUDES INTERSTATE 235 BETWEEN MILE MARKERS 1 AND 14.

LAT...LON 4157 9377 4184 9405 4186 9384 4186 9335
      4166 9335
TIME...MOT...LOC 1328Z 258DEG 33KT 4174 9365
WIND...HAIL 60MPH 1.00IN

$$

671 
WWUS53 KDMX 061343
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
843 AM CDT SUN MAY 6 2012

IAC049-153-061353-
/O.EXP.KDMX.SV.W.0078.000000T0000Z-120506T1345Z/
POLK IA-DALLAS IA-
843 AM CDT SUN MAY 6 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DALLAS AND POLK
COUNTIES WILL EXPIRE AT 845 AM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
 HOWEVER GUSTY WINDS ARE STILL POSSIBLE WITH THIS THUNDERSTORM.

LAT...LON 4157 9377 4184 9405 4186 9384 4186 9335
      4166 9335
TIME...MOT...LOC 1343Z 258DEG 33KT 4177 9347

$$

ZOGG

The office that day

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

Issued	Product	Office	Counties	Lasted
May 6, 4:32 AM CDT	Severe Thunderstorm Warning	DMX	Hamilton, Wright	43 min
May 6, 5:52 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Guthrie	53 min
May 6, 6:30 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Cass	45 min
May 6, 7:05 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Dallas, Guthrie, Madison	25 min
May 6, 7:09 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Madison	22 min
May 6, 7:29 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Dallas, Guthrie, Madison	31 min
May 6, 8:27 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion, Polk, Warren	48 min
May 6, 9:03 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion	42 min
May 6, 9:12 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion	48 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012 Every severe thunderstorm warning in 2012

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.