Alert archive / Iowa / Tornado Warnings in 2011
Tornado Warning 22, NWS Des Moines, IA
NWS Des Moines, IA issued this tornado warning at Apr 9, 2011, 9:55 PM CDT for Palo Alto County, Pocahontas County, Iowa. It was in force for 35 min. 5 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
- Apr 9, 2011, 9:55 PM CDT (02:55 UTC)
- Expired
- Apr 9, 2011, 10:30 PM CDT
- In force
- 35 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
Counties Palo Alto County, IA, Pocahontas County, IA
The radar
The Des Moines radar (KDMX), 144 km from the middle of the area, began a volume at 02:55 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 |
|---|---|---|---|
| Apr 9, 9:55 PM CDT | TORNADO | Varina, IA | LOCATION APPROXIMATE. NEAR VARINA TOWARD THE POCAHONTAS/BUENA VISTA COUNTY LINE. |
| Apr 9, 10:03 PM CDT | HAIL 1 | 2 Ese Laurens, IA | |
| Apr 9, 10:09 PM CDT | HAIL 1.5 | 1 Nw Pocahontas, IA | |
| Apr 9, 10:17 PM CDT | TORNADO | 1 W Pocahontas, IA | LARGE WEDGE TORNADO IN PROGRESS. |
| Apr 9, 10:35 PM CDT | HAIL 2.75 | Laurens, IA | PUBLIC REPORTED BASEBALL SIZE HAIL AND URBAN FLOODING |
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 |
|---|---|---|---|
| Apr 9, 5:48 PM CDT | Tornado Watch | SPC | 7 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 2.9 hours before the alert went out and 224 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.
- Mixed-layer CAPE
- 3327 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 1533 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 270 m²/s²
- 0-3 km storm-relative helicity
- 403 m²/s²
- Significant tornado parameter
- 3.7
- Supercell composite
- 19.0
The text
As transmitted, in the capitals the NWS used until 2016.
386
WFUS53 KDMX 100255
TORDMX
IAC147-151-100330-
/O.NEW.KDMX.TO.W.0022.110410T0255Z-110410T0330Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
955 PM CDT SAT APR 9 2011
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
* TORNADO WARNING FOR...
SOUTHEASTERN PALO ALTO COUNTY IN NORTHWEST IOWA...
POCAHONTAS COUNTY IN NORTHWEST IOWA...
* UNTIL 1030 PM CDT
* AT 951 PM CDT...LOCAL LAW ENFORCEMENT REPORTED A TORNADO 7 MILES
SOUTHEAST OF ALBERT CITY...OR 18 MILES EAST OF STORM LAKE. DOPPLER
RADAR SHOWED THIS TORNADO MOVING NORTHEAST AT 25 MPH.
* LOCATIONS IMPACTED INCLUDE...
LAURENS...POCAHONTAS...HAVELOCK...MALLARD...PLOVER...ROLFE...WEST
BEND AND RODMAN.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TO REPEAT...A TORNADO IS ON THE GROUND. THIS IS A DANGEROUS STORM.
IMMEDIATELY SEEK SHELTER IN A BASEMENT...OR IN AN INTERIOR ROOM OF A
REINFORCED BUILDING. STAY AWAY FROM WINDOWS.
IF YOU ARE OUTSIDE...IN A MOBILE HOME...OR IN A VEHICLE...SEEK
SHELTER IN A NEARBY REINFORCED BUILDING. AS A LAST RESORT...FIND THE
LOWEST SPOT AVAILABLE AND COVER YOUR HEAD.
&&
LAT...LON 4306 9445 4280 9444 4275 9445 4257 9492
4286 9492
TIME...MOT...LOC 0255Z 237DEG 22KT 4273 9482
$$3 follow-up statements
329
WWUS53 KDMX 100305
SVSDMX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1005 PM CDT SAT APR 9 2011
IAC147-151-100330-
/O.CON.KDMX.TO.W.0022.000000T0000Z-110410T0330Z/
POCAHONTAS IA-PALO ALTO IA-
1005 PM CDT SAT APR 9 2011
...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN PALO ALTO AND
POCAHONTAS COUNTIES UNTIL 1030 PM CDT...
AT 1004 PM CDT...LOCAL LAW ENFORCEMENT REPORTED A TORNADO. THIS
TORNADO WAS LOCATED NEAR POCAHONTAS...OR 24 MILES EAST OF STORM
LAKE...MOVING NORTHEAST AT 25 MPH.
THIS STORM HAS A HISTORY OF TORNADO DAMAGE...AND MULTIPLE REPORTS OF
A CONFIRMED TORNADO.
LOCATIONS IMPACTED INCLUDE...
POCAHONTAS...HAVELOCK...MALLARD...PLOVER...ROLFE...WEST BEND AND
RODMAN.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS IS A DANGEROUS STORM. IMMEDIATELY SEEK SHELTER IN A BASEMENT...
OR IN AN INTERIOR ROOM OF A REINFORCED BUILDING. STAY AWAY FROM
WINDOWS.
IF YOU ARE OUTSIDE...IN A MOBILE HOME...OR IN A VEHICLE...SEEK
SHELTER IN A NEARBY REINFORCED BUILDING. AS A LAST RESORT...FIND THE
LOWEST SPOT AVAILABLE AND COVER YOUR HEAD.
&&
LAT...LON 4306 9445 4280 9444 4275 9445 4257 9492
4286 9492
TIME...MOT...LOC 0305Z 237DEG 22KT 4276 9475
$$060
WWUS53 KDMX 100315
SVSDMX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1015 PM CDT SAT APR 9 2011
IAC147-151-100330-
/O.CON.KDMX.TO.W.0022.000000T0000Z-110410T0330Z/
POCAHONTAS IA-PALO ALTO IA-
1015 PM CDT SAT APR 9 2011
...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN PALO ALTO AND
NORTHERN POCAHONTAS COUNTIES UNTIL 1030 PM CDT...
AT 1012 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
STORM WAS LOCATED 6 MILES NORTHWEST OF POCAHONTAS...OR 27 MILES
NORTHEAST OF STORM LAKE...MOVING NORTHEAST AT 25 MPH.
LOCATIONS IMPACTED INCLUDE...
HAVELOCK...PLOVER...MALLARD...ROLFE...WEST BEND AND RODMAN.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS IS A DANGEROUS STORM. IMMEDIATELY SEEK SHELTER IN A BASEMENT...
OR IN AN INTERIOR ROOM OF A REINFORCED BUILDING. STAY AWAY FROM
WINDOWS.
IF YOU ARE OUTSIDE...IN A MOBILE HOME...OR IN A VEHICLE...SEEK
SHELTER IN A NEARBY REINFORCED BUILDING. AS A LAST RESORT...FIND THE
LOWEST SPOT AVAILABLE AND COVER YOUR HEAD.
&&
LAT...LON 4306 9445 4280 9444 4275 9445 4266 9469
4286 9491
TIME...MOT...LOC 0316Z 229DEG 21KT 4282 9470
$$630
WWUS53 KDMX 100320
SVSDMX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1020 PM CDT SAT APR 9 2011
IAC147-151-100330-
/O.CON.KDMX.TO.W.0022.000000T0000Z-110410T0330Z/
POCAHONTAS IA-PALO ALTO IA-
1020 PM CDT SAT APR 9 2011
...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN PALO ALTO AND
NORTHEASTERN POCAHONTAS COUNTIES UNTIL 1030 PM CDT...
AT 1017 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
STORM WAS LOCATED 6 MILES NORTH OF POCAHONTAS...OR 28 MILES SOUTHWEST
OF ALGONA...MOVING NORTHEAST AT 30 MPH.
LOCATIONS IMPACTED INCLUDE...
MALLARD...PLOVER...ROLFE...WEST BEND AND RODMAN.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS IS A DANGEROUS STORM. IMMEDIATELY SEEK SHELTER IN A BASEMENT...
OR IN AN INTERIOR ROOM OF A REINFORCED BUILDING. STAY AWAY FROM
WINDOWS.
IF YOU ARE OUTSIDE...IN A MOBILE HOME...OR IN A VEHICLE...SEEK
SHELTER IN A NEARBY REINFORCED BUILDING. AS A LAST RESORT...FIND THE
LOWEST SPOT AVAILABLE AND COVER YOUR HEAD.
&&
LAT...LON 4306 9445 4280 9444 4275 9445 4270 9459
4291 9478
TIME...MOT...LOC 0320Z 246DEG 27KT 4282 9464
$$The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 7:09 PM CDT | Tornado Warning | DMX | Crawford | 51 min |
| Apr 9, 7:58 PM CDT | Tornado Warning | DMX | Sac | 47 min |
| Apr 9, 8:23 PM CDT | Tornado Warning | DMX | Sac | 22 min |
| Apr 9, 8:41 PM CDT | Tornado Warning | DMX | Sac | 34 min |
| Apr 9, 8:57 PM CDT | Severe Thunderstorm Warning | DMX | Kossuth, Palo Alto | 33 min |
| Apr 9, 9:11 PM CDT | Tornado Warning | DMX | Calhoun, Pocahontas, Sac | 49 min |
| Apr 9, 9:19 PM CDT | Severe Thunderstorm Warning | DMX | Sac | 26 min |
| Apr 9, 9:48 PM CDT | Severe Thunderstorm Warning | DMX | Hancock, Kossuth, Winnebago | 42 min |
| Apr 9, 10:12 PM CDT | Tornado Warning | DMX | Hancock, Kossuth | 33 min |
| Apr 9, 10:18 PM CDT | Tornado Warning | DMX | Cerro Gordo, Hancock, Winnebago, Worth | 42 min |
| Apr 9, 10:22 PM CDT | Tornado Warning | DMX | Pocahontas | 38 min |
| Apr 9, 10:28 PM CDT | Tornado Warning | DMX | Humboldt, Kossuth, Palo Alto, Pocahontas | 47 min |
| Apr 9, 10:54 PM CDT | Tornado Warning | DMX | Humboldt, Kossuth, Palo Alto, Pocahontas | 51 min |
| Apr 9, 10:58 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Worth | 25 min |
| Apr 9, 11:11 PM CDT | Tornado Warning | DMX | Kossuth, Palo Alto | 12 min |
| Apr 9, 11:24 PM CDT | Severe Thunderstorm Warning | DMX | Emmet, Kossuth, Palo Alto | 36 min |
| Apr 9, 11:29 PM CDT | Tornado Warning | DMX | Hancock, Kossuth, Winnebago | 33 min |
| Apr 9, 11:36 PM CDT | Tornado Warning | DMX | Emmet, Palo Alto | 39 min |
| Apr 9, 11:41 PM CDT | Severe Thunderstorm Warning | DMX | Kossuth, Winnebago | 49 min |
| Apr 9, 11:55 PM CDT | Tornado Warning | DMX | Kossuth, Palo Alto | 35 min |
| Apr 9, 11:58 PM CDT | Severe Thunderstorm Warning | DMX | Winnebago, Worth | 32 min |
| Apr 10, 12:24 AM CDT | Severe Thunderstorm Warning | DMX | Hancock, Kossuth, Winnebago, Worth | 31 min |
| Apr 10, 12:53 AM CDT | Severe Thunderstorm Warning | DMX | Worth | 22 min |
| Apr 10, 1:07 AM CDT | Severe Thunderstorm Warning | DMX | Sac | 38 min |
| Apr 10, 1:38 AM CDT | Severe Thunderstorm Warning | DMX | Calhoun, Humboldt, Pocahontas, Webster | 52 min |
| Apr 10, 3:54 AM CDT | Wind Advisory | DMX | Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 33 more | 15 hr |
Nearby
Tornado Warnings in Iowa, 2011Every tornado warning in 2011Tornadoes 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.