Alert archive / Iowa / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 409

June 11, 200211 counties in Iowa; 4 counties in Minnesota; 7 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jun 11, 2002, 1:30 AM CDT for 11 counties in Iowa; 4 counties in Minnesota; 7 counties in Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 11, 2002, 1:30 AM CDT (06:30 UTC)
Expired: Jun 11, 2002, 7:00 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 22 counties

Allamakee County, IA, Black Hawk County, IA, Bremer County, IA, Chickasaw County, IA, Clayton County, IA, Fayette County, IA, Floyd County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Worth County, IA, Fillmore County, MN, Houston County, MN, Mower County, MN, Winona County, MN, Crawford County, WI, Jackson County, WI, La Crosse County, WI, Monroe County, WI, Richland County, WI, Trempealeau County, WI, Vernon County, WI

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 11, 3:34 AM CDT	Flash Flood Warning	ARX	Fillmore	4 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 6.5 hours before the alert went out and 202 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: 2859 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 872 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 204 m²/s²
Significant tornado parameter: 1.6
Supercell composite: 9.5

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 110907
SEL9  
SPC WW 110620
IAZ000-MNZ000-WIZ000-111200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 409
STORM PREDICTION CENTER NORMAN OK
120 AM CDT TUE JUN 11 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   NORTHEAST IOWA                               
   SOUTHEAST MINNESOTA                          
   SOUTHWEST WISCONSIN                          

EFFECTIVE THIS TUESDAY MORNING FROM 130 AM UNTIL 700 AM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 45 STATUTE MILES
EITHER SIDE OF A LINE FROM 35 MILES NORTHWEST OF WATERLOO IOWA TO
10 MILES NORTH OF CAMP DOUGLAS WISCONSIN.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...  CONTINUE...WW 408...

DISCUSSION...LINE OF SEVERE STORMS OVER CENTRAL IA WILL CONTINUE TO
SURGE NORTHEASTWARD...WHILE LINE OF STORMS OVER SOUTHEAST MN TRACK
SOUTHEASTWARD INTO WW AREA.  BOTH LINES OF STORMS WILL LIKELY
MAINTAIN A RISK OF GUSTY/DAMAGING WINDS FOR SEVERAL MORE HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM
MOTION VECTOR 24045.

...HART

433,0931 444,0903 432,0895 421,0923

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 10, 9:30 PM CDT	Severe Thunderstorm Watch	SPC	Audubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 18 more	5 hr
Jun 11, 5:45 PM CDT	Tornado Watch	SPC	Crawford, Fremont, Harrison, Mills, Montgomery, Page and 2 more	5 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2002 Severe Thunderstorm Watches in Wisconsin, 2002 Severe Thunderstorm Watches in Minnesota, 2002 Every severe thunderstorm watch in 2002

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.