Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 5, NWS Quad Cities, IA

May 22, 2011Benton County, Iowa County, Linn County, Iowa

NWS Quad Cities, IA issued this tornado warning at May 22, 2011, 2:45 PM CDT for Benton County, Iowa County, Linn County, Iowa. It was in force for 29 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
May 22, 2011, 2:45 PM CDT (19:45 UTC)
Expired
May 22, 2011, 3:14 PM CDT
In force
29 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon

Counties Benton County, IA, Iowa County, IA, Linn County, IA

The radar

The Quad Cities radar (KDVN), 128 km from the middle of the area, began a volume at 19:47 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.

IssuedProductOfficeLasted
May 22, 12:51 PM CDTTornado WatchSPC10 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.8 hours before the alert went out and 134 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 12:00Z on 2011-05-22Temperature 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 12:00Z on 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 233 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1775 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
233 m²/s²
0-3 km storm-relative helicity
287 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.

300 
WFUS53 KDVN 221945
TORDVN
IAC011-095-113-222030-
/O.NEW.KDVN.TO.W.0005.110522T1945Z-110522T2030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
245 PM CDT SUN MAY 22 2011

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN BENTON COUNTY IN EAST CENTRAL IOWA...
  NORTHWESTERN IOWA COUNTY IN EAST CENTRAL IOWA...
  WEST CENTRAL LINN COUNTY IN EAST CENTRAL IOWA...

* UNTIL 330 PM CDT.

* AT 243 PM CDT...TRAINED SPOTTERS REPORTED A TORNADO NEAR LADORA...
  OR 7 MILES NORTHWEST OF MARENGO...MOVING NORTHEAST AT 30 MPH.

* THE TORNADO WILL BE NEAR...
  BLAIRSTOWN AROUND 255 PM CDT...
  WATKINS AND VAN HORNE AROUND 300 PM CDT...
  NORWAY AROUND 305 PM CDT...
  NEWHALL AROUND 310 PM CDT...
  ATKINS AROUND 320 PM CDT...
  PALO AND SHELLSBURG AROUND 325 PM CDT...

THIS INCLUDES INTERSTATE 380 IN IOWA BETWEEN MILE MARKERS 22 AND 32.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE IN A TORNADO IS IN A BASEMENT OR INTERIOR ROOM
OR HALLWAY ON THE LOWEST FLOOR OF A BUILDING.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM CDT SUNDAY EVENING FOR
EASTERN IOWA AND NORTHWESTERN ILLINOIS AND NORTHEAST MISSOURI.

&&

LAT...LON 4195 9222 4218 9184 4205 9153 4170 9230
      4170 9231
TIME...MOT...LOC 1946Z 236DEG 28KT 4187 9214

$$

ERVIN
3 follow-up statements
299 
WWUS53 KDVN 221952
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
252 PM CDT SUN MAY 22 2011

IAC011-095-113-222030-
/O.CON.KDVN.TO.W.0005.000000T0000Z-110522T2030Z/
LINN IA-IOWA IA-BENTON IA-
252 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM CDT FOR
SOUTHEASTERN BENTON...NORTH CENTRAL IOWA AND WEST CENTRAL LINN
COUNTIES...

AT 247 PM CDT...TRAINED SPOTTERS REPORTED A TORNADO.  THIS TORNADO
WAS LOCATED APPROXIMATELY NEAR BLAIRSTOWN...OR NEAR MARENGO...MOVING
NORTHEAST AT 30 MPH.

THE TORNADO WILL BE NEAR...
  WATKINS AROUND 300 PM CDT...
  NORWAY AROUND 305 PM CDT...
  NEWHALL AROUND 310 PM CDT...
  ATKINS AROUND 315 PM CDT...
  PALO AND SHELLSBURG AROUND 325 PM CDT...
  HIAWATHA...TODDVILLE...ROBINS AND MIDWAY AROUND 330 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS ALREADY PRODUCED A TORNADO AND REMAINS A THREAT.

THIS STORM IS ALSO CAPABLE OF PRODUCING LARGE HAIL THE SIZE OF
QUARTERS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM CDT SUNDAY EVENING FOR
EASTERN IOWA AND NORTHWESTERN ILLINOIS AND NORTHEAST MISSOURI.

&&

LAT...LON 4195 9219 4216 9184 4205 9153 4174 9222
TIME...MOT...LOC 1952Z 236DEG 28KT 4188 9207

$$

ERVIN
426 
WWUS53 KDVN 221959
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
259 PM CDT SUN MAY 22 2011

IAC011-095-113-222030-
/O.CON.KDVN.TO.W.0005.000000T0000Z-110522T2030Z/
LINN IA-IOWA IA-BENTON IA-
259 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM CDT FOR
SOUTHEASTERN BENTON...NORTH CENTRAL IOWA AND WEST CENTRAL LINN
COUNTIES...

AT 251 PM CDT...TRAINED SPOTTERS REPORTED A TORNADO.  THIS TORNADO
WAS LOCATED APPROXIMATELY NEAR WATKINS...OR 7 MILES NORTH OF
MARENGO...MOVING NORTHEAST AT 30 MPH.

THE TORNADO WILL BE NEAR...
  NORWAY AROUND 305 PM CDT...
  NEWHALL AROUND 310 PM CDT...
  ATKINS AROUND 315 PM CDT...
  HIAWATHA AND 8 MILES WEST OF MARION AROUND 330 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM IS ALSO CAPABLE OF PRODUCING LARGE HAIL THE SIZE OF 
QUARTERS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM CDT SUNDAY EVENING FOR
EASTERN IOWA AND NORTHWESTERN ILLINOIS AND NORTHEAST MISSOURI.

&&

LAT...LON 4194 9212 4206 9183 4205 9153 4174 9222
TIME...MOT...LOC 1959Z 236DEG 28KT 4191 9201

$$

ERVIN
439 
WWUS53 KDVN 222014
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
314 PM CDT SUN MAY 22 2011

IAC011-095-113-222024-
/O.CAN.KDVN.TO.W.0005.000000T0000Z-110522T2030Z/
LINN IA-IOWA IA-BENTON IA-
314 PM CDT SUN MAY 22 2011

...THE TORNADO WARNING FOR SOUTHEASTERN BENTON...NORTH CENTRAL IOWA
AND WEST CENTRAL LINN COUNTIES IS CANCELLED...

THE THUNDERSTORM THAT WAS CAPABLE OF PRODUCING  TORNADO HAS 
WEAKENED. THEREFORE THE TORNADO WARNING HAS BEEN CANCELLED.

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING BREIF HEAVY RAIN

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM CDT SUNDAY EVENING FOR
EASTERN IOWA AND NORTHWESTERN ILLINOIS AND NORTHEAST MISSOURI.

LAT...LON 4194 9212 4206 9183 4205 9153 4174 9222
TIME...MOT...LOC 2014Z 236DEG 28KT 4197 9188

$$

ERVIN

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 10:09 PM CDTSpecial Weather StatementDVNIowa, Jefferson, Keokuk51 min
May 22, 2:01 PM CDTSevere Thunderstorm WarningDVNBenton, Iowa44 min
May 22, 2:06 PM CDTSevere Thunderstorm WarningDVNIowa, Keokuk, Washington54 min
May 22, 2:34 PM CDTSevere Thunderstorm WarningDVNBenton, Iowa, Linn33 min
May 22, 2:38 PM CDTTornado WarningDVNBenton, Iowa, Johnson, Keokuk, Linn67 min
May 22, 3:22 PM CDTTornado WarningDVNCedar, Iowa, Johnson53 min
May 22, 3:25 PM CDTSevere Thunderstorm WarningDVNCedar, Iowa, Johnson, Jones, Linn65 min
May 22, 3:43 PM CDTSevere Thunderstorm WarningDVNIowa, Johnson, Keokuk, Washington47 min
May 22, 4:12 PM CDTSevere Thunderstorm WarningDVNCedar, Clinton, Jackson, Jones63 min
May 22, 4:17 PM CDTSevere Thunderstorm WarningDVNJefferson, Keokuk, Washington43 min
May 22, 4:17 PM CDTSevere Thunderstorm WarningDVNIowa, Johnson, Keokuk, Washington43 min
May 22, 4:32 PM CDTSevere Thunderstorm WarningDVNCedar, Clinton, Johnson58 min
May 22, 4:47 PM CDTSevere Thunderstorm WarningDVNClinton, Jackson58 min
May 22, 4:56 PM CDTSevere Thunderstorm WarningDVNCedar, Clinton, Jackson, Scott64 min
May 22, 5:25 PM CDTSevere Thunderstorm WarningDVNCedar, Clinton, Jackson, Muscatine, Scott50 min
May 22, 5:28 PM CDTSevere Thunderstorm WarningDVNClinton, Jackson62 min
May 22, 5:47 PM CDTSevere Thunderstorm WarningDVNClinton, Scott31 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.