Alert archive / Illinois / Tornado Watches in 2004
Tornado Watch 440
The Storm Prediction Center issued this tornado watch at Jun 11, 2004, 6:20 PM CDT for 16 counties in Illinois; 8 counties in Wisconsin. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 11, 2004, 6:20 PM CDT (23:20 UTC)
- Expired
- Jun 11, 2004, 11:00 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 24 counties
Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, Grundy County, IL, Jo Daviess County, IL, Kane County, IL, Kendall County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Putnam County, IL, Stephenson County, IL, Whiteside County, IL, Winnebago County, IL, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Jefferson County, WI, Lafayette County, WI, Rock County, WI, Walworth County, WI
The radar
The Milwaukee radar (KMKX), 87 km from the middle of the area, began a volume at 23:24 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
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 11, 6:51 PM CDT | Tornado Warning | MKX | Green, Lafayette | 54 min |
| Jun 11, 7:16 PM CDT | Flash Flood Warning | MKX | Green | 3 hr |
| Jun 11, 7:20 PM CDT | Severe Thunderstorm Warning | LOT | Ogle, Winnebago | 40 min |
| Jun 11, 7:55 PM CDT | Severe Thunderstorm Warning | LOT | Boone, Winnebago | 65 min |
| Jun 11, 9:44 PM CDT | Severe Thunderstorm Warning | LOT | Boone | 31 min |
| Jun 11, 9:47 PM CDT | Severe Thunderstorm Warning | LOT | Kendall, LaSalle | 43 min |
| Jun 11, 10:37 PM CDT | Severe Thunderstorm Warning | LOT | Grundy, Kendall | 23 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
Green Bay/Straub, WI (KGRB), launched 12:00Z, 11.3 hours before the alert went out and 251 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 534 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 82 m²/s²
- 0-3 km storm-relative helicity
- 101 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 112316
SEL0
SPC WW 112320
ILZ000-WIZ000-120400-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 440
NWS STORM PREDICTION CENTER NORMAN OK
620 PM CDT FRI JUN 11 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
NORTHERN ILLINOIS
SOUTHERN WISCONSIN
EFFECTIVE THIS FRIDAY EVENING FROM 620 PM UNTIL 1100 PM CDT.
TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES EAST AND WEST
OF A LINE FROM 55 MILES NORTHWEST OF JANESVILLE WISCONSIN TO 20
MILES SOUTHWEST OF MARSEILLES ILLINOIS.
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 435...WW 437...WW 438...WW
439...
DISCUSSION...SUPERCELLS EXPECTED TO DEVELOP ALONG WNW/ESE ORIENTED
WARM FRONT DURING THE NEXT FEW HOURS...WHERE LOW LCLS AND SELY LOW
LEVEL FLOW WILL BE FAVORABLE FOR LOW LEVEL STORM ROTATION/POSSIBLE
TORNADOES.
AVIATION...TORNADOES AND 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 550.
MEAN STORM MOTION VECTOR 24030.
...CORFIDI
431,0884 410,0875 410,0900 431,0905SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 10, 7:58 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Champaign, DeWitt, Douglas, Edgar and 27 more | 92 min |
| Jun 10, 9:50 PM CDT | Tornado Watch | SPC | Cook, DuPage, Kankakee, Will | 5 hr |
| Jun 11, 5:56 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, DeKalb, DuPage, Grundy and 14 more | 94 min |
| Jun 11, 10:10 AM CDT | Mesoscale Discussion | SPC | Buffalo, Crawford, Grant, La Crosse, Pepin, Pierce and 3 more | 95 min |
| Jun 11, 5:00 PM CDT | Tornado Watch | SPC | Barron, Buffalo, Dunn, Pepin, Pierce, Polk and 2 more | 6 hr |
Nearby
Tornado 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.