Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 73, NWS Quad Cities, IA

August 4, 201211 counties in Iowa; Rock Island County, Illinois

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 4, 2012, 12:38 PM CDT for 11 counties in Iowa; Rock Island County, Illinois. It was in force for 67 min. 11 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
Aug 4, 2012, 12:38 PM CDT (17:38 UTC)
Expired
Aug 4, 2012, 1:45 PM CDT
In force
67 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Cedar County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Washington County, IA, Rock Island County, IL

The radar

The Quad Cities radar (KDVN), 40 km from the middle of the area, began a volume at 17:40 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
Aug 4, 1:12 PM CDTTSTM WND DMG1 Ene Dewitt, IAA 5 INCH TREE LIMB DOWN. REPORT WAS DELAYED.
Aug 4, 1:14 PM CDTTSTM WND GST 652 E Bennett, IA
Aug 4, 1:14 PM CDTTSTM WND GST 722 S Clarence, IAREPORT VIA ESPOTTER.
Aug 4, 1:16 PM CDTTSTM WND GST 705 E Ryan, IAESTIMATED 60 TO 70 MPH WINDS. RELAYED BY DELAWARE COUNTY SHERIFFS OFFICE.
Aug 4, 1:17 PM CDTTSTM WND GST 60Tipton, IAREPORT VIA ESPOTTER
Aug 4, 1:20 PM CDTTSTM WND GST 70Wheatland, IATIME ESTIMATED
Aug 4, 1:35 PM CDTTSTM WND DMG1 S Low Moor, IAFRUIT TREE DOWNED
Aug 4, 1:47 PM CDTHAIL 0.253 Sse Charlotte, IAE50 MPH WINDS WITH 2-3 INCH BRANCHES DOWN
Aug 4, 1:53 PM CDTTSTM WND GST 50Davenport, IAESTIMATED 40-50 MPH WITH NO HAIL YET. VIA ESPOTTER.
Aug 4, 1:54 PM CDTTSTM WND GST 57Clinton Municipal Airpo, IA
Aug 4, 1:54 PM CDTTSTM WND GST 60Davenport, IA

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.

IssuedProductOfficeLasted
Aug 4, 10:50 AM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 5.6 hours before the alert went out and 44 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 2012-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1247 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 12:00Z on 2012-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
1247 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1158 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

780 
WUUS53 KDVN 041738
SVRDVN
IAC031-045-055-061-097-103-105-115-139-163-183-ILC161-041845-
/O.NEW.KDVN.SV.W.0073.120804T1738Z-120804T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1238 PM CDT SAT AUG 4 2012

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CEDAR COUNTY IN EAST CENTRAL IOWA...
  CLINTON COUNTY IN EAST CENTRAL IOWA...
  JACKSON COUNTY IN EAST CENTRAL IOWA...
  SOUTHEASTERN JOHNSON COUNTY IN EAST CENTRAL IOWA...
  JONES COUNTY IN EAST CENTRAL IOWA...
  MUSCATINE COUNTY IN EAST CENTRAL IOWA...
  SCOTT COUNTY IN EAST CENTRAL IOWA...
  SOUTHEASTERN DELAWARE COUNTY IN NORTHEAST IOWA...
  DUBUQUE COUNTY IN NORTHEAST IOWA...
  CENTRAL ROCK ISLAND COUNTY IN NORTHWEST ILLINOIS...
  NORTHWESTERN LOUISA COUNTY IN SOUTHEAST IOWA...
  EAST CENTRAL WASHINGTON COUNTY IN SOUTHEAST IOWA...

* UNTIL 145 PM CDT.

* AT 1232 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS
  IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED APPROXIMATELY ALONG
  A LINE EXTENDING FROM DELHI TO LETTS...OR ALONG A LINE EXTENDING
  FROM 8 MILES SOUTHEAST OF MANCHESTER TO 7 MILES NORTHEAST OF
  COLUMBUS JUNCTION...AND MOVING EAST AT 30 MPH.

THIS STORM HAS A HISTORY OF PRODUCING 60 TO 70 MPH WINDS.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO   
ANAMOSA...FRUITLAND...MONTICELLO...TIPTON...DYERSVILLE...BLUE 
GRASS...MAQUOKETA...DUBUQUE...DAVENPORT...ELDRIDGE...DEWITT...  
CLINTON.

THIS INCLUDES INTERSTATE 80 IN IOWA BETWEEN MILE MARKERS 254 AND 298.

THIS INCLUDES INTERSTATE 74 IN IOWA BETWEEN MILE MARKERS 1 AND 5.

THIS INCLUDES INTERSTATE 280 BETWEEN MILE MARKERS 1 AND 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. MOVE IMMEDIATELY INDOORS AND STAY AWAY
FROM WINDOWS.

&&

LAT...LON 4239 9061 4238 9048 4222 9039 4212 9017
      4181 9018 4173 9032 4177 9053 4152 9049
      4142 9103 4134 9107 4133 9107 4130 9153
      4149 9152 4142 9137 4230 9136 4230 9148
      4244 9147 4259 9068
TIME...MOT...LOC 1735Z 270DEG 26KT 4239 9134 4134 9123
WIND...HAIL 70MPH <1.00IN

$$

NICHOLS
2 follow-up statements
348 
WWUS53 KDVN 041817
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
117 PM CDT SAT AUG 4 2012

IAC103-115-183-041823-
/O.CAN.KDVN.SV.W.0073.000000T0000Z-120804T1845Z/
WASHINGTON IA-LOUISA IA-JOHNSON IA-
117 PM CDT SAT AUG 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN JOHNSON...
NORTHERN LOUISA AND EAST CENTRAL WASHINGTON COUNTIES IS CANCELLED...

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

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING GUSTY WINDS OVER 
40 MPH.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 500 PM CDT
SATURDAY AFTERNOON FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

LAT...LON 4259 9068 4239 9061 4238 9048 4222 9039
      4212 9017 4181 9018 4173 9032 4177 9053
      4152 9049 4142 9103 4133 9107 4133 9124
      4144 9116 4182 9105 4214 9137 4230 9136
      4230 9144 4240 9138
TIME...MOT...LOC 1813Z 270DEG 26KT 4239 9097 4134 9086

$$

IAC031-045-055-061-097-105-139-163-ILC161-041845-
/O.CON.KDVN.SV.W.0073.000000T0000Z-120804T1845Z/
SCOTT IA-MUSCATINE IA-JACKSON IA-DUBUQUE IA-DELAWARE IA-CEDAR IA-
CLINTON IA-JONES IA-ROCK ISLAND IL-
117 PM CDT SAT AUG 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR CENTRAL ROCK ISLAND...JONES...CLINTON...EASTERN CEDAR...
SOUTHEASTERN DELAWARE...DUBUQUE...JACKSON...EASTERN MUSCATINE AND
SCOTT COUNTIES...

AT 111 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED
APPROXIMATELY ALONG A LINE EXTENDING FROM FARLEY TO 9 MILES SOUTH OF
MIDWAY BEACH...OR ALONG A LINE EXTENDING FROM 17 MILES SOUTHWEST OF
DUBUQUE TO 11 MILES SOUTHEAST OF MUSCATINE...MOVING EAST AT 30 MPH.

THIS LINE OF STORMS OF HAS A PRODUCED NUMEROUS REPORTS OF 60 TO 70 
MPH WINDS IN THE PAST 30 MINUTES.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
EPWORTH...BLUE GRASS...MAQUOKETA...DAVENPORT...PARKVIEW...DEWITT... 
CLINTON...AND BELLEVUE.

THIS INCLUDES INTERSTATE 80 IN IOWA BETWEEN MILE MARKERS 268 AND 298.

THIS INCLUDES INTERSTATE 74 IN IOWA BETWEEN MILE MARKERS 1 AND 5.

THIS INCLUDES INTERSTATE 280 BETWEEN MILE MARKERS 1 AND 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 500 PM CDT
SATURDAY AFTERNOON FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

&&

LAT...LON 4259 9068 4239 9061 4238 9048 4222 9039
      4212 9017 4181 9018 4173 9032 4177 9053
      4152 9049 4142 9103 4133 9107 4133 9124
      4144 9116 4182 9105 4214 9137 4230 9136
      4230 9144 4240 9138
TIME...MOT...LOC 1813Z 270DEG 26KT 4239 9097 4134 9086
WIND...HAIL 70MPH <1.00IN

$$

NICHOLS
559 
WWUS53 KDVN 041845
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
145 PM CDT SAT AUG 4 2012

IAC031-045-055-061-097-105-139-163-ILC161-041855-
/O.EXP.KDVN.SV.W.0073.000000T0000Z-120804T1845Z/
SCOTT IA-MUSCATINE IA-JACKSON IA-DUBUQUE IA-DELAWARE IA-CEDAR IA-
CLINTON IA-JONES IA-ROCK ISLAND IL-
145 PM CDT SAT AUG 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL ROCK ISLAND...JONES...
CLINTON...EASTERN CEDAR...SOUTHEASTERN DELAWARE...DUBUQUE...
JACKSON...EASTERN MUSCATINE AND SCOTT COUNTIES HAS EXPIRED...

HOWEVER...STRONG GUSTU WINDS OVER 40 MPH ARE STILL POSSIBLE UNTIL 2 PM.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 500 PM CDT
SATURDAY AFTERNOON FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

LAT...LON 4259 9068 4239 9061 4238 9048 4222 9039
      4212 9017 4181 9018 4173 9032 4177 9053
      4152 9049 4142 9103 4133 9107 4133 9124
      4144 9116 4182 9105 4214 9137 4230 9136
      4230 9144 4240 9138
TIME...MOT...LOC 1845Z 270DEG 26KT 4239 9066 4134 9055

$$

NICHOLS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 11:18 AM CDTSpecial Weather StatementDVNBenton, Buchanan, Delaware, Henry, Iowa, Jefferson and 4 more102 min
Aug 4, 12:05 PM CDTSevere Thunderstorm WarningDVNBenton, Buchanan, Delaware, Iowa, Johnson, Keokuk and 2 more55 min
Aug 4, 12:59 PM CDTSevere Thunderstorm WarningDVNDes Moines, Louisa, Muscatine, Scott76 min
Aug 4, 1:19 PM CDTFlash Flood WarningDVNLinn82 min
Aug 4, 1:39 PM CDTFlash Flood WarningDVNScott70 min
Aug 4, 1:36 PM CDTSevere Thunderstorm WarningDVNBureau, Carroll, Henry, Jo Daviess, Putnam, Stephenson and 1 more84 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012Severe Thunderstorm Warnings in Illinois, 2012Every severe thunderstorm warning in 2012

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.