Alert archive / Illinois / Severe Thunderstorm Watches in 2004
Severe Thunderstorm Watch 577
The Storm Prediction Center issued this severe thunderstorm watch at Jul 6, 2004, 6:50 AM CDT for 25 counties in Illinois; 17 counties in Missouri. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 6, 2004, 6:50 AM CDT (11:50 UTC)
- Expired
- Jul 6, 2004, 11:00 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
All 42 counties
Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Washington County, IL, Audrain County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Lincoln County, MO, Maries County, MO, Miller County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 26 km from the middle of the area, began a volume at 11:54 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.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 7:48 AM CDT | Severe Thunderstorm Warning | LSX | Greene, Macoupin | 42 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
Lincoln, IL (KILX), launched 00:00Z, 11.8 hours before the alert went out and 238 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
- 193 J/kg
- Mixed-layer CIN
- -133 J/kg
- Mixed-layer LCL
- 1600 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 166 m²/s²
- 0-3 km storm-relative helicity
- 184 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.7
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 061151
SEL7
SPC WW 061150
ILZ000-MOZ000-061600-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 577
NWS STORM PREDICTION CENTER NORMAN OK
650 AM CDT TUE JUL 6 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
WESTERN AND CENTRAL ILLINOIS
EASTERN MISSOURI
EFFECTIVE THIS TUESDAY MORNING FROM 650 AM UNTIL 1100 AM CDT.
HAIL TO 1.5 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 85 STATUTE MILES
EAST AND WEST OF A LINE FROM 15 MILES NORTH NORTHWEST OF
SPRINGFIELD ILLINOIS TO 40 MILES EAST OF VICHY MISSOURI.
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 575...WW 576...
DISCUSSION...THUNDERSTORMS EXPECTED TO EXPAND EWD ALONG W/E
FRONT/MOISTURE GRADIENT TO THE N OF STL. AREA VWP AND PROFILER DATA
SHOW AMPLE WLY FLOW ALOFT TO SUPPORT A FEW BOWING SEGMENTS WITH HIGH
WIND AND...GIVEN DEGREE OF ELEVATED INSTABILITY...POSSIBLY HAIL.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 26040.
...CORFIDI
400,0881 380,0892 380,0923 400,0912SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 5, 7:05 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Greene, Jersey, Macoupin, Madison and 2 more | 55 min |
| Jul 5, 9:10 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Christian, Clark, Clay, Clinton, Coles and 18 more | 4 hr |
| Jul 5, 9:29 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Henderson, Henry, Jo Daviess, Lee and 8 more | 61 min |
| Jul 5, 11:14 PM CDT | Mesoscale Discussion | SPC | Champaign, DeWitt, Douglas, Edgar, Ford, Iroquois and 13 more | 91 min |
| Jul 5, 11:44 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Clark, Clay, Clinton, Coles and 26 more | 91 min |
| Jul 6, 9:00 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Champaign, Christian and 28 more | 60 min |
| Jul 6, 11:01 AM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Clay, Clinton, Crawford, Cumberland and 29 more | 59 min |
| Jul 6, 12:10 PM CDT | Severe Thunderstorm Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more | 6 hr |
| Jul 6, 2:34 PM CDT | Mesoscale Discussion | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more | 56 min |
| Jul 6, 2:53 PM CDT | Mesoscale Discussion | SPC | Bond, Champaign, Christian, Clark, Clay, Clinton and 33 more | 37 min |
| Jul 6, 3:25 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Champaign, Christian, Clark, Clay, Coles and 30 more | 8 hr |
| Jul 6, 5:37 PM CDT | Mesoscale Discussion | SPC | Alexander, Johnson, Pulaski, Union | 53 min |
| Jul 5, 10:00 PM CDT | Severe Thunderstorm Watch | SPC | Andrew, Atchison, Buchanan, Holt, Nodaway, Worth | 6 hr |
| Jul 6, 1:16 AM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Buchanan, Holt, Nodaway, Worth | 119 min |
| Jul 6, 2:45 AM CDT | Mesoscale Discussion | SPC | Audrain, Bates, Benton, Boone, Buchanan, Caldwell and 33 more | 2 hr |
| Jul 6, 3:10 AM CDT | Severe Thunderstorm Watch | SPC | Barton, Bates, Benton, Boone, Buchanan, Caldwell and 30 more | 5 hr |
| Jul 6, 3:50 AM CDT | Severe Thunderstorm Watch | SPC | Barry, McDonald, Stone | 5 hr |
| Jul 6, 5:18 AM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Boone, Camden and 33 more | 117 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2004Severe Thunderstorm Watches in Missouri, 2004Every severe thunderstorm 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.