Alert archive / Illinois / Tornado Warnings in 2011

Tornado Warning 16, NWS Quad Cities, IA

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

NWS Quad Cities, IA issued this tornado warning at Jul 27, 2011, 9:16 PM CDT for Jackson County, Iowa; Carroll County, Jo Daviess County, Illinois. It was in force for 31 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
Jul 27, 2011, 9:16 PM CDT (02:16 UTC)
Expired
Jul 27, 2011, 9:47 PM CDT
In force
31 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon

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

The radar

The Quad Cities radar (KDVN), 72 km from the middle of the area, began a volume at 02:19 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
Jul 27, 7:43 PM CDTTornado WatchSPC5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.3 hours before the alert went out and 68 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.

396 
WFUS53 KDVN 280216
TORDVN
IAC097-ILC015-085-280300-
/O.NEW.KDVN.TO.W.0016.110728T0216Z-110728T0300Z/

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

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN JACKSON COUNTY IN EAST CENTRAL IOWA...
  CARROLL COUNTY IN NORTHWEST ILLINOIS...
  SOUTHERN JO DAVIESS COUNTY IN NORTHWEST ILLINOIS...

* UNTIL 1000 PM CDT.

* AT 911 PM CDT...DOPPLER RADAR INDICATED A TORNADO NEAR 
  WHITTON...OR 15 MILES SOUTH OF GALENA...MOVING EAST AT 25 MPH.
  SPOTTERS HAVE REPORTED A FUNNEL CLOUD IN NORTHEAST JACKSON COUNTY 
  WITH THIS STORM.


* THE TORNADO WILL BE NEAR...
  WHITTON AND HANOVER AROUND 915 PM CDT...
  GREEN ISLAND AND REECEVILLE AROUND 920 PM CDT...
  MISSISSIPPI PALISADES AROUND 935 PM CDT...
  SABULA AROUND 940 PM CDT...
  SAVANNA AROUND 945 PM CDT...
  CENTER HILL AND WACKER AROUND 955 PM CDT...

THIS WARNING REPLACES THE EARLIER TORNADO WARNING FOR JACKSON COUNTY.

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.

&&

LAT...LON 4216 8980 4194 8991 4215 9049 4231 9041
TIME...MOT...LOC 0214Z 291DEG 21KT 4220 9033

$$

LE
2 follow-up statements
844 
WWUS53 KDVN 280241
SVSDVN

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

ILC085-280250-
/O.CAN.KDVN.TO.W.0016.000000T0000Z-110728T0300Z/
JO DAVIESS IL-
941 PM CDT WED JUL 27 2011

...THE TORNADO WARNING FOR SOUTH CENTRAL JO DAVIESS COUNTY IS
CANCELLED...

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

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING VERY HEAVY 
RAINFALL...AND MAY PRODUCE LOCALIZED FLOODING.

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

LAT...LON 4216 8980 4194 8991 4212 9038 4220 9031
      4220 8997
TIME...MOT...LOC 0240Z 291DEG 21KT 4214 9014

$$

IAC097-ILC015-280300-
/O.CON.KDVN.TO.W.0016.000000T0000Z-110728T0300Z/
JACKSON IA-CARROLL IL-
941 PM CDT WED JUL 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT FOR WESTERN
CARROLL AND SOUTHEASTERN JACKSON COUNTIES...

AT 936 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED APPROXIMATELY NEAR
MISSISSIPPI PALISADES...OR 11 MILES WEST OF MOUNT CARROLL...MOVING
EAST AT 25 MPH.

THE TORNADO WILL BE NEAR...
  SAVANNA AROUND 945 PM CDT...
  CENTER HILL AND WACKER AROUND 955 PM CDT...
  MOUNT CARROLL...ARGO FAY...8 MILES NORTHWEST OF CHADWICK AND 8
  MILES WEST OF LANARK AROUND 1000 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4216 8980 4194 8991 4212 9038 4220 9031
      4220 8997
TIME...MOT...LOC 0240Z 291DEG 21KT 4214 9014

$$

LE
961 
WWUS53 KDVN 280247
SVSDVN

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

IAC097-ILC015-280257-
/O.CAN.KDVN.TO.W.0016.000000T0000Z-110728T0300Z/
JACKSON IA-CARROLL IL-
947 PM CDT WED JUL 27 2011

...THE TORNADO WARNING FOR CARROLL AND SOUTHEASTERN JACKSON COUNTIES
IS CANCELLED...

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

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING VERY HEAVY 
RAINFALL AND LOCALIZED FLOODING.

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

LAT...LON 4216 8980 4194 8991 4212 9038 4220 9031
      4220 8997
TIME...MOT...LOC 0247Z 291DEG 21KT 4212 9009

$$

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 WarningDVNDubuque, Jackson9 hr
Jul 27, 7:35 PM CDTTornado WarningDVNDubuque, Jackson40 min
Jul 27, 8:29 PM CDTTornado WarningDVNDubuque, Jackson46 min
Jul 27, 11:55 PM CDTFlash Flood WarningDVNJackson4 hr
Jul 28, 12:50 AM CDTSpecial Weather StatementDVNDelaware, Dubuque, Jackson55 min
Jul 28, 1:13 AM CDTFlash Flood WarningDVNBuchanan, Delaware5 hr
Jul 28, 4:10 AM CDTAreal Flood WarningDVNDelaware, Dubuque, Jackson, Jones12 hr
Jul 28, 9:26 AM CDTSpecial Weather StatementDVNBenton, Buchanan, Delaware, Linn64 min
Jul 28, 9:40 AM CDTSpecial Weather StatementDVNMuscatine, Scott50 min
Jul 28, 10:15 AM CDTRiver Flood WarningDVNDubuque, Jackson6 hr
Jul 28, 10:15 AM CDTRiver Flood WarningDVNJackson6 hr
Jul 28, 12:03 PM CDTHeat AdvisoryDVNDes Moines, Henry, Jefferson, Keokuk, Lee, Louisa and 2 more10 hr
Jul 27, 7:51 PM CDTTornado WarningDVNJo Daviess, Stephenson39 min
Jul 27, 8:40 PM CDTFlash Flood WarningDVNStephenson8 hr
Jul 28, 10:15 AM CDTRiver Flood WarningDVNStephenson43 hr
Jul 28, 3:39 PM CDTAreal Flood WarningDVNCarroll, Jo Daviess, Stephenson6 hr

Nearby

Tornado Warnings in Illinois, 2011Tornado 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.