Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 182, NWS Des Moines, IA

September 7, 20124 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Sep 7, 2012, 3:05 AM CDT for 4 counties in Iowa. It was in force for 40 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
Sep 7, 2012, 3:05 AM CDT (08:05 UTC)
Expired
Sep 7, 2012, 3:45 AM CDT
In force
40 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

What was reported inside it

TimeReportWhereRemark
Sep 7, 3:05 AM CDTHAIL 12 S Stratford, IATIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 8.1 hours before the alert went out and 238 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-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2012-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 275 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2012-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 140 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
275 J/kg
Mixed-layer CIN
-320 J/kg
Mixed-layer LCL
2527 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
140 m²/s²
0-3 km storm-relative helicity
305 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

455 
WUUS53 KDMX 070805
SVRDMX
IAC015-079-169-187-070845-
/O.NEW.KDMX.SV.W.0182.120907T0805Z-120907T0845Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
305 AM CDT FRI SEP 7 2012

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN BOONE COUNTY IN CENTRAL IOWA...
  SOUTHERN HAMILTON COUNTY IN CENTRAL IOWA...
  STORY COUNTY IN CENTRAL IOWA...
  SOUTHERN WEBSTER COUNTY IN CENTRAL IOWA...

* UNTIL 345 AM CDT

* AT 300 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM STORY CITY TO 9 MILES WEST OF OGDEN...AND MOVING SOUTHEAST AT
  50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  AMES...BOONE...NEVADA...HUXLEY...ROLAND...GILBERT...BOONE
  AIRPORT...MCCALLSBURG...LUTHER...AMES AIRPORT...KELLEY...COLO...
  SLATER...SHELDAHL...CAMBRIDGE...MAXWELL AND COLLINS.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 103 AND 133.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR DAMAGING WINDS...FALLING TREES AND FLYING DEBRIS. MOVE
INDOORS AND STAY AWAY FROM WINDOWS. IF YOU ARE IN A MOBILE HOME...
SEEK SHELTER IN A REINFORCED BUILDING.

&&

LAT...LON 4187 9332 4186 9377 4215 9417 4221 9417
      4221 9425 4229 9436 4246 9376 4225 9346
      4221 9346 4221 9341 4208 9323
TIME...MOT...LOC 0805Z 310DEG 43KT 4217 9353 4203 9414
WIND...HAIL 60MPH <.75IN

$$

SKOW
2 follow-up statements
481 
WWUS53 KDMX 070823
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
323 AM CDT FRI SEP 7 2012

IAC187-070833-
/O.CAN.KDMX.SV.W.0182.000000T0000Z-120907T0845Z/
WEBSTER IA-
323 AM CDT FRI SEP 7 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN WEBSTER COUNTY IS
CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE 
WARNED AREA.

LAT...LON 4187 9332 4186 9377 4209 9407 4226 9384
      4242 9373 4225 9346 4221 9346 4221 9341
      4208 9323
TIME...MOT...LOC 0823Z 309DEG 44KT 4211 9332 4191 9380

$$

IAC015-079-169-070845-
/O.CON.KDMX.SV.W.0182.000000T0000Z-120907T0845Z/
STORY IA-HAMILTON IA-BOONE IA-
323 AM CDT FRI SEP 7 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHEASTERN
BOONE...SOUTHEASTERN HAMILTON AND STORY COUNTIES UNTIL 345 AM CDT...

AT 319 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM 10 MILES NORTHEAST OF NEVADA TO 5 MILES NORTH OF MADRID...MOVING
SOUTHEAST AT 50 MPH.

LOCATIONS IMPACTED INCLUDE...
  NEVADA...HUXLEY...KELLEY...SLATER...SHELDAHL...COLO...CAMBRIDGE AND
  MAXWELL.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 103 AND 132.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR DAMAGING WINDS...FALLING TREES AND FLYING DEBRIS. MOVE
INDOORS AND STAY AWAY FROM WINDOWS. IF YOU ARE IN A MOBILE HOME...GET
OUT NOW...AND SEEK SHELTER IN A REINFORCED BUILDING.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS. TURN AROUND DON/T DROWN.

&&

LAT...LON 4187 9332 4186 9377 4209 9407 4226 9384
      4242 9373 4225 9346 4221 9346 4221 9341
      4208 9323
TIME...MOT...LOC 0823Z 309DEG 44KT 4211 9332 4191 9380
WIND...HAIL 60MPH <.75IN

$$

SKOW
454 
WWUS53 KDMX 070838
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
338 AM CDT FRI SEP 7 2012

IAC015-079-169-070849-
/O.EXP.KDMX.SV.W.0182.000000T0000Z-120907T0845Z/
STORY IA-HAMILTON IA-BOONE IA-
338 AM CDT FRI SEP 7 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BOONE...
SOUTHEASTERN HAMILTON AND STORY COUNTIES WILL EXPIRE AT 345 AM CDT...

THE LINE OF STORMS 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 THESE
THUNDERSTORMS.

LAT...LON 4187 9332 4186 9377 4209 9407 4226 9384
      4242 9373 4225 9346 4221 9346 4221 9341
      4208 9323
TIME...MOT...LOC 0839Z 309DEG 44KT 4196 9314 4177 9362

$$

SKOW

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 10:42 PM CDTSevere Thunderstorm WarningDMXCalhoun, Pocahontas, Sac48 min
Sep 6, 11:15 PM CDTSevere Thunderstorm WarningDMXCalhoun, Carroll, Greene, Webster45 min
Sep 6, 11:53 PM CDTSevere Thunderstorm WarningDMXCalhoun, Greene27 min
Sep 7, 1:20 AM CDTSevere Thunderstorm WarningDMXBoone, Greene, Story40 min
Sep 7, 1:45 AM CDTSevere Thunderstorm WarningDMXJasper, Marshall, Poweshiek, Tama45 min
Sep 7, 1:48 AM CDTSevere Thunderstorm WarningDMXCalhoun, Pocahontas, Sac, Webster42 min
Sep 7, 1:58 AM CDTSevere Thunderstorm WarningDMXBoone, Polk, Story47 min
Sep 7, 3:25 AM CDTSevere Thunderstorm WarningDMXJasper, Mahaska, Poweshiek50 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012Every 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.