Alert archive / Iowa / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 2, NWS Des Moines, IA

March 20, 20114 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Mar 20, 2011, 5:27 AM CDT for 4 counties in Iowa. It was in force for 48 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
Mar 20, 2011, 5:27 AM CDT (10:27 UTC)
Expired
Mar 20, 2011, 6:15 AM CDT
In force
48 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Black Hawk County, IA, Grundy County, IA, Marshall County, IA, Tama County, IA

The radar

The Des Moines radar (KDMX), 118 km from the middle of the area, began a volume at 10:28 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

TimeReportWhereRemark
Mar 20, 6:01 AM CDTHAIL 0.88Cedar Falls, IATRAINED SPOTTER IN CEDAR FALLS REPORTS NICKEL SIZED HAIL.

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

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 10.5 hours before the alert went out and 191 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, Davenport, at 00:00Z on 2011-03-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2011-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
0 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
262 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.

444 
WUUS53 KDMX 201027
SVRDMX
IAC013-075-127-171-201115-
/O.NEW.KDMX.SV.W.0002.110320T1027Z-110320T1115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
527 AM CDT SUN MAR 20 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BLACK HAWK COUNTY IN NORTHEAST IOWA...
  SOUTHEASTERN GRUNDY COUNTY IN CENTRAL IOWA...
  NORTHEASTERN MARSHALL COUNTY IN CENTRAL IOWA...
  NORTHWESTERN TAMA COUNTY IN CENTRAL IOWA...

* UNTIL 615 AM CDT

* AT 524 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR CONRAD...OR 11 MILES NORTH OF
  MARSHALLTOWN...AND MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WATERLOO...REINBECK...HUDSON...CEDAR FALLS...EVANSDALE...
  GLADBROOK...LINCOLN...MORRISON...WATERLOO AIRPORT...ELK RUN HEIGHTS
  AND RAYMOND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LARGE HAIL CAN CAUSE INJURY AND PROPERTY DAMAGE. SEEK SAFETY INDOORS
UNTIL THE STORM PASSES.

&&

LAT...LON 4212 9285 4220 9294 4264 9239 4264 9234
      4249 9215
TIME...MOT...LOC 1027Z 228DEG 42KT 4221 9282
WIND...HAIL <50MPH 1.00IN

$$

COGIL
4 follow-up statements
123 
WWUS53 KDMX 201036
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
536 AM CDT SUN MAR 20 2011

IAC127-201046-
/O.CAN.KDMX.SV.W.0002.000000T0000Z-110320T1115Z/
MARSHALL IA-
536 AM CDT SUN MAR 20 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MARSHALL COUNTY
IS CANCELLED...

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

LAT...LON 4219 9272 4228 9284 4264 9239 4264 9234
      4249 9215
TIME...MOT...LOC 1036Z 231DEG 43KT 4226 9268

$$

IAC013-075-171-201115-
/O.CON.KDMX.SV.W.0002.000000T0000Z-110320T1115Z/
BLACK HAWK IA-GRUNDY IA-TAMA IA-
536 AM CDT SUN MAR 20 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
TAMA...SOUTHEASTERN GRUNDY AND BLACK HAWK COUNTIES UNTIL 615 AM
CDT...

AT 532 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
STORM WAS LOCATED 7 MILES EAST OF CONRAD...OR 16 MILES NORTHEAST OF
MARSHALLTOWN...MOVING NORTHEAST AT 50 MPH.

LOCATIONS IMPACTED INCLUDE...
  WATERLOO...REINBECK...HUDSON...CEDAR FALLS...EVANSDALE...
  MORRISON...WATERLOO AIRPORT...ELK RUN HEIGHTS AND RAYMOND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR LARGE HAIL AND DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE
OUTSIDE SHOULD MOVE TO A REINFORCED BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 4219 9272 4228 9284 4264 9239 4264 9234
      4249 9215
TIME...MOT...LOC 1036Z 231DEG 43KT 4226 9268
WIND...HAIL <50MPH 1.00IN

$$

COGIL
837 
WWUS53 KDMX 201047
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
547 AM CDT SUN MAR 20 2011

IAC171-201057-
/O.CAN.KDMX.SV.W.0002.000000T0000Z-110320T1115Z/
TAMA IA-
547 AM CDT SUN MAR 20 2011

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

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

LAT...LON 4229 9253 4230 9256 4239 9271 4264 9239
      4264 9234 4249 9215
TIME...MOT...LOC 1047Z 228DEG 45KT 4236 9255

$$

IAC013-075-201115-
/O.CON.KDMX.SV.W.0002.000000T0000Z-110320T1115Z/
BLACK HAWK IA-GRUNDY IA-
547 AM CDT SUN MAR 20 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR EAST CENTRAL
GRUNDY AND BLACK HAWK COUNTIES UNTIL 615 AM CDT...

AT 545 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
STORM WAS LOCATED NEAR REINBECK...OR 15 MILES SOUTHWEST OF
WATERLOO...MOVING NORTHEAST AT 50 MPH.

LOCATIONS IMPACTED INCLUDE...
  WATERLOO...HUDSON...CEDAR FALLS...EVANSDALE...WATERLOO AIRPORT...
  ELK RUN HEIGHTS AND RAYMOND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR LARGE HAIL AND DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE
OUTSIDE SHOULD MOVE TO A REINFORCED BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 4229 9253 4230 9256 4239 9271 4264 9239
      4264 9234 4249 9215
TIME...MOT...LOC 1047Z 228DEG 45KT 4236 9255
WIND...HAIL <50MPH 1.00IN

$$

COGIL
302 
WWUS53 KDMX 201055
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
555 AM CDT SUN MAR 20 2011

IAC075-201105-
/O.CAN.KDMX.SV.W.0002.000000T0000Z-110320T1115Z/
GRUNDY IA-
555 AM CDT SUN MAR 20 2011

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL GRUNDY COUNTY IS
CANCELLED...

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

LAT...LON 4231 9249 4251 9256 4264 9239 4264 9234
      4249 9215
TIME...MOT...LOC 1055Z 233DEG 47KT 4243 9243

$$

IAC013-201115-
/O.CON.KDMX.SV.W.0002.000000T0000Z-110320T1115Z/
BLACK HAWK IA-
555 AM CDT SUN MAR 20 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR BLACK HAWK
COUNTY UNTIL 615 AM CDT...

AT 553 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
STORM WAS LOCATED NEAR HUDSON...OR 8 MILES SOUTHWEST OF WATERLOO...
MOVING NORTHEAST AT 55 MPH.

LOCATIONS IMPACTED INCLUDE...
  WATERLOO...CEDAR FALLS...EVANSDALE...WATERLOO AIRPORT...ELK RUN
  HEIGHTS AND RAYMOND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR LARGE HAIL AND DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE
OUTSIDE SHOULD MOVE TO A REINFORCED BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 4231 9249 4251 9256 4264 9239 4264 9234
      4249 9215
TIME...MOT...LOC 1055Z 233DEG 47KT 4243 9243
WIND...HAIL <50MPH 1.00IN

$$

COGIL
659 
WWUS53 KDMX 201112
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
612 AM CDT SUN MAR 20 2011

IAC013-201122-
/O.EXP.KDMX.SV.W.0002.000000T0000Z-110320T1115Z/
BLACK HAWK IA-
612 AM CDT SUN MAR 20 2011

...THE SEVERE THUNDERSTORM WARNING FOR BLACK HAWK COUNTY WILL EXPIRE
AT 615 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 SMALL HAIL IS STILL POSSIBLE WITH THIS THUNDERSTORM.

LAT...LON 4231 9249 4251 9256 4264 9239 4264 9234
      4249 9215
TIME...MOT...LOC 1112Z 233DEG 36KT 4256 9226

$$

COGIL

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 20, 3:28 AM CDTSevere Thunderstorm WarningDMXAudubon, Carroll47 min
Mar 20, 11:11 AM CDTRiver Flood WarningDMXBlack Hawk8 days

Nearby

Severe Thunderstorm Warnings in Iowa, 2011Every severe thunderstorm warning 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.