Alert archive / Wisconsin / Tornado Watches in 2004

Tornado Watch 824

September 15, 20044 states

The Storm Prediction Center issued this tornado watch at Sep 15, 2004, 12:25 PM CDT for 4 states. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Sep 15, 2004, 12:25 PM CDT (17:25 UTC)
Expired
Sep 15, 2004, 8:00 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
All 73 counties

Allamakee County, IA, Bremer County, IA, Butler County, IA, Chickasaw County, IA, Clayton County, IA, Fayette County, IA, Floyd County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Gogebic County, MI, Iron County, MI, Carlton County, MN, Dodge County, MN, Fillmore County, MN, Goodhue County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Pine County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Ashland County, WI, Barron County, WI, Bayfield County, WI, Buffalo County, WI, Burnett County, WI, Chippewa County, WI, Clark County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Douglas County, WI, Dunn County, WI, Eau Claire County, WI, Florence County, WI, Forest County, WI, Grant County, WI, Green Lake County, WI, Iowa County, WI, Iron County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, La Crosse County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marquette County, WI, Menominee County, WI, Monroe County, WI, Oneida County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Portage County, WI, Price County, WI, Richland County, WI, Rusk County, WI, Saint Croix County, WI, Sauk County, WI, Sawyer County, WI, Shawano County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Vilas County, WI, Washburn County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 51 km from the middle of the area, began a volume at 17:26 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

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

IssuedProductOfficeCountiesLasted
Sep 15, 2:50 PM CDTSevere Thunderstorm WarningGRBLincoln, Marathon, Wood55 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

Minneapolis, MN (KMPX), launched 12:00Z, 5.4 hours before the alert went out and 204 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, Minneapolis, MN at 12:00Z on 2004-09-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 joules per kilogram.LCLEL10008507005003002001001 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, Minneapolis, MN at 12:00Z on 2004-09-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 square meters per square second.1939587897Sfc1 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
4 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
473 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
5 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 151726
SEL4  
SPC WW 151725
IAZ000-MIZ000-MNZ000-WIZ000-LSZ000-160100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 824
NWS STORM PREDICTION CENTER NORMAN OK
1225 PM CDT WED SEP 15 2004

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

       FAR NORTHEAST IOWA
       WESTERN UPPER MICHIGAN
       FAR EASTERN MINNESOTA
       WESTERN AND NORTHERN WISCONSIN
       LAKE SUPERIOR

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 1225 PM UNTIL
800 PM CDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 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 50 MILES SOUTHWEST OF LONEROCK WISCONSIN TO 20
MILES WEST NORTHWEST OF IRONWOOD MICHIGAN.

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 823...

DISCUSSION...STRONG SURFACE LOW AHEAD OF NEGATIVELY TILTED MID/UPPER
LEVEL TROUGH WILL CONTINUE LIFTING NNEWD TOWARDS WRN LAKE SUPERIOR
THIS AFTERNOON...WITH COLD FRONT TRAILING SSWWD ACROSS WRN/CENTRAL
WI INTO NERN IA.  AIR MASS HAS DESTABILIZED AND IS WEAKLY CAPPED
EAST OF THE SURFACE LOW AND SWD ALONG THE COLD FRONT SUGGESTING
THUNDERSTORMS MAY FORM SOON OVER WRN PORTIONS OF WATCH.  VERY STRONG
LOW AND DEEP LAYER SHEAR SUPPORTS FAST MOVING SUPERCELLS AND SMALL
LINES WITH THREATS OF DAMAGING WINDS AND A FEW TORNADOES MOVING
ENEWD INTO THE EARLY EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 24040.


...EVANS

424,0925 463,0924 463,0881 424,0884

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 14, 7:17 PM CDTMesoscale DiscussionSPCAdair, Audubon, Boone, Buena Vista, Calhoun, Carroll and 32 more118 min
Sep 14, 8:16 PM CDTMesoscale DiscussionSPCAllamakee, Chickasaw, Howard, Mitchell, Winneshiek3 hr
Sep 15, 4:00 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Benton, Black Hawk and 37 more3 hr
Sep 15, 3:23 PM CDTMesoscale DiscussionSPCDickinson, Gogebic, Iron, Menominee97 min
Sep 15, 10:47 AM CDTMesoscale DiscussionSPCChisago, Dakota, Dodge, Fillmore, Goodhue, Houston and 6 more88 min

Nearby

Tornado Watches in Wisconsin, 2004Tornado Watches in Iowa, 2004Tornado Watches in Minnesota, 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.