Alert archive / Iowa / Tornado Watches in 2004

Tornado Watch 566

July 5, 200415 counties in Illinois; 57 counties in Iowa; Crawford County, Grant County, Wisconsin

The Storm Prediction Center issued this tornado watch at Jul 5, 2004, 4:20 PM CDT for 15 counties in Illinois; 57 counties in Iowa; Crawford County, Grant County, Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 5, 2004, 4:20 PM CDT (21:20 UTC)
Expired
Jul 5, 2004, 10:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 74 counties

Allamakee County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Clinton County, IA, Davis County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Henry County, IA, Howard County, IA, Humboldt County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Kossuth County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mitchell County, IA, Monroe County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Scott County, IA, Story County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Bureau County, IL, Carroll County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Marshall County, IL, Mercer County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Warren County, IL, Whiteside County, IL, Woodford County, IL, Crawford County, WI, Grant County, WI

The radar

The Quad Cities radar (KDVN), 121 km from the middle of the area, began a volume at 21:21 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.

Warnings issued inside it

15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 5, 4:38 PM CDTFlash Flood WarningDVNBuchanan3 hr
Jul 5, 4:39 PM CDTFlash Flood WarningARXFayette4 hr
Jul 5, 5:13 PM CDTTornado WarningARXFayette32 min
Jul 5, 5:52 PM CDTTornado WarningARXHoward38 min
Jul 5, 6:33 PM CDTTornado WarningARXFayette27 min
Jul 5, 6:54 PM CDTFlash Flood WarningDMXCerro Gordo4 hr
Jul 5, 7:25 PM CDTFlash Flood WarningARXFloyd, Mitchell3 hr
Jul 5, 7:42 PM CDTSevere Thunderstorm WarningDVNCedar, Louisa, Muscatine48 min
Jul 5, 7:57 PM CDTFlash Flood WarningDVNBuchanan6 hr
Jul 5, 8:14 PM CDTSevere Thunderstorm WarningDVNHenry, Mercer, Rock Island46 min
Jul 5, 8:24 PM CDTSevere Thunderstorm WarningILXKnox66 min
Jul 5, 8:55 PM CDTTornado WarningDVNHenry35 min
Jul 5, 9:07 PM CDTTornado WarningDVNWhiteside38 min
Jul 5, 9:29 PM CDTTornado WarningILXKnox61 min
Jul 5, 9:40 PM CDTTornado WarningDVNBureau, Henry50 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.3 hours before the alert went out and 126 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 2004-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 477 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2004-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 square meters per square second.19395878Sfc1 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
477 J/kg
Mixed-layer CIN
-177 J/kg
Mixed-layer LCL
1211 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
81 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.

000 
WWUS20 KWNS 052118
SEL6  
SPC WW 052120
IAZ000-ILZ000-WIZ000-060300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 566
NWS STORM PREDICTION CENTER NORMAN OK
420 PM CDT MON JUL 5 2004

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       NORTHERN AND EASTERN IOWA
       NORTHWESTERN ILLINOIS
       SOUTHWESTERN WISCONSIN

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 420 PM UNTIL 1000
PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 105 STATUTE MILES EAST AND
WEST OF A LINE FROM 35 MILES NORTHEAST OF MASON CITY IOWA TO 15
MILES SOUTHEAST OF BURLINGTON IOWA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 562...WW 563...WW 564...WW
565...

DISCUSSION...SHEAR AND INSTABILITY NOW FAVORABLE FOR SUPERCELLS
AHEAD OF SURFACE AND UPPER LOW MOVING SLOWLY NEWD ACROSS SWRN IA. 
THUNDERSTORMS WILL CONTINUE TO INCREASE REMAINDER OF AFTERNOON THIS
AREA WITH INCREASING THREAT OF TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 22030.


...HALES

432,0904 403,0885 403,0925 432,0945

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 5, 6:55 AM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Christian, Clinton, Coles, Cumberland and 12 more4 hr
Jul 5, 9:12 AM CDTMesoscale DiscussionSPCBond, Calhoun, Christian, Clark, Clay, Clinton and 34 more63 min
Jul 5, 9:45 AM CDTSevere Thunderstorm WatchSPCClay, Edwards, Franklin, Gallatin, Hamilton, Jackson and 8 more4 hr
Jul 5, 12:08 PM CDTMesoscale DiscussionSPCEdwards, Hardin, Lawrence, Richland, Wabash67 min
Jul 5, 3:00 PM CDTMesoscale DiscussionSPCAdams, Brown, Hancock, Henderson, McDonough, Mercer and 3 more60 min
Jul 5, 3:43 PM CDTMesoscale DiscussionSPCBond, Calhoun, Clinton, Jackson, Jersey, Madison and 5 more92 min
Jul 5, 4:00 PM CDTTornado WatchSPCAdams, Brown, Calhoun, Cass, Fulton, Greene and 15 more6 hr
Jul 5, 6:30 PM CDTMesoscale DiscussionSPCBureau, Carroll, Henry, Jo Daviess, Mercer, Rock Island and 1 more60 min
Jul 4, 11:05 PM CDTSevere Thunderstorm WatchSPCFremont, Mills5 hr
Jul 5, 1:16 AM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Buena Vista, Calhoun and 25 more89 min
Jul 5, 2:00 AM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Boone, Calhoun and 31 more5 hr
Jul 5, 4:45 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Boone, Buena Vista and 30 more2 hr

Nearby

Tornado Watches in Iowa, 2004Tornado Watches in Illinois, 2004Tornado Watches in Wisconsin, 2004Every tornado watch in 2004

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.