Alert archive / Iowa / Tornado Watches in 2004

Tornado Watch 655

July 19, 200411 counties in Illinois; 29 counties in Iowa; 5 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Jul 19, 2004, 1:40 PM CDT for 11 counties in Illinois; 29 counties in Iowa; 5 counties in Wisconsin. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 19, 2004, 1:40 PM CDT (18:40 UTC)
Expired: Jul 19, 2004, 7:00 PM CDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 45 counties

Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Cedar County, IA, Chickasaw County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Henry County, IA, Howard County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Winneshiek County, IA, Carroll County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Mercer County, IL, Peoria County, IL, Rock Island County, IL, Stark County, IL, Warren County, IL, Whiteside County, IL, Crawford County, WI, Grant County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI

The radar

The Quad Cities radar (KDVN), 90 km from the middle of the area, began a volume at 18:40 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 19, 1:54 PM CDT	Severe Thunderstorm Warning	ARX	Allamakee	96 min
Jul 19, 2:55 PM CDT	Severe Thunderstorm Warning	ARX	Winneshiek	80 min
Jul 19, 2:59 PM CDT	Tornado Warning	ARX	Winneshiek	76 min
Jul 19, 4:00 PM CDT	Severe Thunderstorm Warning	ARX	Fayette	90 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, 6.7 hours before the alert went out and 91 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1160 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 129 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 191839
SEL5  
SPC WW 191840
IAZ000-ILZ000-WIZ000-200000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 655
NWS STORM PREDICTION CENTER NORMAN OK
140 PM CDT MON JUL 19 2004

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

       EASTERN IOWA
       NORTHWEST ILLINOIS
       SOUTHWEST WISCONSIN

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 140 PM UNTIL 700
PM CDT.

TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 65 MILES WEST NORTHWEST OF LONEROCK WISCONSIN TO 20
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.

DISCUSSION...SEVERE THUNDERSTORMS WILL INCREASE AND DEVELOP INTO
NERN IA/SWRN WI  AHEAD OF SURFACE COLD FRONT.  VERY FAVORABLE
VEERING SHEAR PROFILES FOR SUPERCELLS AND AS AIR MASS CONTINUES TO
DESTABILIZE DURING AFTERNOON POTENTIAL FOR ISOLATED TORNADOES WILL
INCREASE.  ADDITIONALLY VERY LARGE HAIL LIKELY AND DAMAGING WINDS
COULD INCREASE AS STORMS EVOLVE INTO BOW ECHOS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 34030.


...HALES

433,0895 403,0893 403,0921 433,0924

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 19, 3:26 PM CDT	Mesoscale Discussion	SPC	Carroll, Henderson, Henry, Jo Daviess, Knox, Mercer and 5 more	2 hr
Jul 19, 12:26 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 36 more	3 hr
Jul 19, 6:31 PM CDT	Mesoscale Discussion	SPC	Forest, Langlade, Lincoln, Oneida, Price, Sawyer and 1 more	89 min

Nearby

Tornado Watches in Iowa, 2004 Tornado Watches in Illinois, 2004 Tornado Watches in Wisconsin, 2004 Every 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.