Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 13, NWS Quad Cities, IA

July 27, 2011Jo Daviess County, Illinois; Dubuque County, Jackson County, Iowa

NWS Quad Cities, IA issued this tornado warning at Jul 27, 2011, 7:35 PM CDT for Jo Daviess County, Illinois; Dubuque County, Jackson County, Iowa. It was in force for 40 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
Jul 27, 2011, 7:35 PM CDT (00:35 UTC)
Expired
Jul 27, 2011, 8:15 PM CDT
In force
40 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon

Counties Dubuque County, IA, Jackson County, IA, Jo Daviess County, IL

The radar

The Quad Cities radar (KDVN), 89 km from the middle of the area, began a volume at 00:37 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
Jul 27, 7:55 PM CDTTORNADO3 Ne Stockton, ILPOSSIBLE TORNADO TOUCHDOWN NEAR JO DAVIES / STEPHENSON COUNTY LINE...RELAYED EMERGENCY MANAGER.
Jul 27, 8:04 PM CDTHAIL 1Apple Canyon Lake, ILTIME 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

Davenport, (KDVN), launched 00:00Z, 0.6 hours before the alert went out and 88 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 2011-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4556 joules per kilogram.LCLLFCEL10008507005003002001001 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 2011-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 141 square meters per square second.193958Sfc1 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
4556 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
962 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
316 m²/s²
Significant tornado parameter
3.9
Supercell composite
19.4

Open this sounding in Storm Lab

The text

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

491 
WFUS53 KDVN 280035
TORDVN
IAC061-097-ILC085-280115-
/O.NEW.KDVN.TO.W.0013.110728T0035Z-110728T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
735 PM CDT WED JUL 27 2011

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTH CENTRAL JACKSON COUNTY IN EAST CENTRAL IOWA...
  SOUTHEASTERN DUBUQUE COUNTY IN NORTHEAST IOWA...
  JO DAVIESS COUNTY IN NORTHWEST ILLINOIS...

* UNTIL 815 PM CDT.

* AT 728 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  A POSSIBLE TORNADO NEAR DUBUQUE REGIONAL AIRPORT...OR 8 MILES 
  SOUTH OF DUBUQUE...MOVING EAST AT 25 MPH.  ANOTHER STORM WITH A 
  POSSIBLE TORNADO IS 5 MILES SOUTHEAST OF GALENA...ALSO MOVING EAST 
  AT 25 MPH.

* THE TORNADO WILL BE NEAR...
  MASSEY AROUND 740 PM CDT...
  ST. DONATUS AROUND 745 PM CDT...
  GALENA...AIKEN...RICE AND SMITHS THROUGH 800 PM CDT...
  GALENA TERRITORY AND RODDEN THROUGH 810 PM CDT...
  GUILFORD THROUGH 815 PM CDT...

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.

PLEASE REPORT ANY SEVERE WEATHER OR DAMAGE TO YOUR LOCAL LAW
ENFORCEMENT AGENCY FOR RELAY TO THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 4248 9060 4248 8993 4226 8993 4231 9074
      4243 9074
TIME...MOT...LOC 0033Z 266DEG 21KT 4239 9063

$$

LE
2 follow-up statements
185 
WWUS53 KDVN 280056
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
756 PM CDT WED JUL 27 2011

IAC061-097-280104-
/O.CAN.KDVN.TO.W.0013.000000T0000Z-110728T0115Z/
JACKSON IA-DUBUQUE IA-
756 PM CDT WED JUL 27 2011

...THE TORNADO WARNING FOR SOUTHEASTERN DUBUQUE AND NORTH CENTRAL
JACKSON COUNTIES IS CANCELLED...

THE THUNDERSTORM THAT WAS CAPABLE OF PRODUCING A TORNADO HAS MOVED 
EAST OUT OF THE WARNED AREA. THEREFORE THE TORNADO WARNING HAS BEEN 
CANCELLED.

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING VERY HEAVY 
RAINFALL WITH RAINFALL RATES OF OVER AN INCH AN HOUR.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 AM CDT THURSDAY MORNING
FOR NORTHEASTERN IOWA AND NORTHWEST ILLINOIS.

LAT...LON 4248 8993 4226 8993 4229 9041 4233 9042
      4238 9047 4248 9045
TIME...MOT...LOC 0054Z 266DEG 21KT 4240 9046

$$

ILC085-280115-
/O.CON.KDVN.TO.W.0013.000000T0000Z-110728T0115Z/
JO DAVIESS IL-
756 PM CDT WED JUL 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR CENTRAL
JO DAVIESS COUNTY...

AT 750 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A POSSIBLE TORNADO.  THIS TORNADO WAS LOCATED APPROXIMATELY 
NEAR GALENA...MOVING EAST AT 25 MPH.

THE TORNADO WILL BE NEAR...
  GALENA...AIKEN AND RICE AROUND 800 PM CDT...
  GALENA TERRITORY AND RODDEN AROUND 810 PM CDT...
  GUILFORD...SCHAPVILLE...SCALES MOUND AND APPLE CANYON LAKE AROUND
  815 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT ANY SEVERE WEATHER OR DAMAGE TO YOUR LOCAL LAW
ENFORCEMENT AGENCY FOR RELAY TO THE NATIONAL WEATHER SERVICE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 AM CDT THURSDAY MORNING
FOR NORTHEASTERN IOWA AND NORTHWEST ILLINOIS.

&&

LAT...LON 4248 8993 4226 8993 4229 9041 4233 9042
      4238 9047 4248 9045
TIME...MOT...LOC 0054Z 266DEG 21KT 4240 9046

$$

LE
856 
WWUS53 KDVN 280114
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
814 PM CDT WED JUL 27 2011

ILC085-280124-
/O.EXP.KDVN.TO.W.0013.000000T0000Z-110728T0115Z/
JO DAVIESS IL-
814 PM CDT WED JUL 27 2011

...THE TORNADO WARNING FOR CENTRAL JO DAVIESS COUNTY WILL EXPIRE AT
815 PM CDT...

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING VERY HEAVY 
RAINFALL...STRONG GUSTY WINDS AND SMALL HAIL.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 AM CDT THURSDAY MORNING
FOR NORTHEASTERN IOWA AND NORTHWEST ILLINOIS.

LAT...LON 4248 8993 4226 8993 4229 9041 4233 9042
      4238 9047 4248 9045
TIME...MOT...LOC 0114Z 266DEG 21KT 4241 9030

$$

LE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 7:10 PM CDTFlash Flood WarningDVNJo Daviess9 hr
Jul 27, 7:51 PM CDTTornado WarningDVNJo Daviess, Stephenson39 min
Jul 27, 8:40 PM CDTFlash Flood WarningDVNStephenson8 hr
Jul 27, 9:16 PM CDTTornado WarningDVNCarroll, Jo Daviess31 min
Jul 27, 11:55 PM CDTFlash Flood WarningDVNCarroll4 hr
Jul 28, 12:50 AM CDTSpecial Weather StatementDVNCarroll, Jo Daviess, Stephenson55 min
Jul 28, 4:10 AM CDTAreal Flood WarningDVNCarroll, Jo Daviess, Stephenson12 hr
Jul 28, 9:40 AM CDTSpecial Weather StatementDVNRock Island, Whiteside50 min
Jul 28, 10:15 AM CDTRiver Flood WarningDVNJo Daviess6 hr
Jul 28, 10:15 AM CDTRiver Flood WarningDVNCarroll, Jo Daviess6 hr
Jul 28, 10:15 AM CDTRiver Flood WarningDVNStephenson43 hr
Jul 28, 12:03 PM CDTHeat AdvisoryDVNHancock, Henderson, McDonough, Mercer, Warren10 hr
Jul 28, 3:39 PM CDTAreal Flood WarningDVNCarroll, Jo Daviess, Stephenson6 hr
Jul 27, 8:29 PM CDTTornado WarningDVNDubuque, Jackson46 min
Jul 28, 1:13 AM CDTFlash Flood WarningDVNBuchanan, Delaware5 hr
Jul 28, 9:26 AM CDTSpecial Weather StatementDVNBenton, Buchanan, Delaware, Linn64 min

Nearby

Tornado Warnings in Iowa, 2011Tornado Warnings in Illinois, 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.