Alert archive / Illinois / Severe Thunderstorm Watches in 2004
Severe Thunderstorm Watch 790
The Storm Prediction Center issued this severe thunderstorm watch at Aug 27, 2004, 1:25 AM CDT for 4 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 27, 2004, 1:25 AM CDT (06:25 UTC)
- Expired
- Aug 27, 2004, 7:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 70 counties
Boone County, IL, Bureau County, IL, Cook County, IL, DeKalb County, IL, DeWitt County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McHenry County, IL, McLean County, IL, Peoria County, IL, Putnam County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Will County, IL, Woodford County, IL, Benton County, IN, Jasper County, IN, Lake County, IN, LaPorte County, IN, Newton County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Allegan County, MI, Arenac County, MI, Barry County, MI, Bay County, MI, Berrien County, MI, Cass County, MI, Clare County, MI, Clinton County, MI, Eaton County, MI, Gladwin County, MI, Gratiot County, MI, Ionia County, MI, Isabella County, MI, Kalamazoo County, MI, Kent County, MI, Lake County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Osceola County, MI, Ottawa County, MI, Saginaw County, MI, Van Buren County, MI, Kenosha County, WI, Milwaukee County, WI, Racine County, WI
Warnings issued inside it
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 1:33 AM CDT | Severe Thunderstorm Warning | LOT | Boone, DeKalb | 42 min |
| Aug 27, 1:35 AM CDT | Severe Thunderstorm Warning | DVN | Hancock | 45 min |
| Aug 27, 1:56 AM CDT | Severe Thunderstorm Warning | ILX | Knox | 64 min |
| Aug 27, 1:56 AM CDT | Severe Thunderstorm Warning | LOT | Kane, McHenry | 49 min |
| Aug 27, 2:06 AM CDT | Severe Thunderstorm Warning | GRR | Muskegon | 24 min |
| Aug 27, 2:07 AM CDT | Severe Thunderstorm Warning | MKX | Kenosha | 53 min |
| Aug 27, 2:19 AM CDT | Severe Thunderstorm Warning | ILX | Fulton, Schuyler | 56 min |
| Aug 27, 2:22 AM CDT | Severe Thunderstorm Warning | MKX | Racine | 38 min |
| Aug 27, 2:30 AM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Kendall, Lake, LaSalle, Will | 45 min |
| Aug 27, 2:34 AM CDT | Severe Thunderstorm Warning | GRR | Mason | 56 min |
| Aug 27, 3:15 AM CDT | Severe Thunderstorm Warning | GRR | Lake | 30 min |
| Aug 27, 3:53 AM CDT | Severe Thunderstorm Warning | GRR | Allegan, Muskegon, Ottawa | 37 min |
| Aug 27, 4:13 AM CDT | Severe Thunderstorm Warning | GRR | Newaygo, Oceana | 32 min |
| Aug 27, 4:49 AM CDT | Severe Thunderstorm Warning | GRR | Mecosta, Montcalm | 26 min |
| Aug 27, 5:03 AM CDT | Severe Thunderstorm Warning | GRR | Isabella | 27 min |
| Aug 27, 5:09 AM CDT | Severe Thunderstorm Warning | DTX | Midland | 81 min |
| Aug 27, 5:15 AM CDT | Severe Thunderstorm Warning | GRR | Clare | 30 min |
| Aug 27, 5:22 AM CDT | Severe Thunderstorm Warning | APX | Gladwin | 38 min |
| Aug 27, 5:32 AM CDT | Severe Thunderstorm Warning | DTX | Bay | 58 min |
| Aug 27, 5:43 AM CDT | Severe Thunderstorm Warning | APX | Arenac | 47 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 00:00Z, 6.4 hours before the alert went out and 199 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
- 3587 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 948 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 132 m²/s²
- 0-3 km storm-relative helicity
- 211 m²/s²
- Significant tornado parameter
- 3.5
- Supercell composite
- 18.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 9:13 PM CDT | Mesoscale Discussion | SPC | Carroll, Jo Daviess, Rock Island, Stephenson | 62 min |
| Aug 26, 9:45 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Carroll, Henderson, Henry, Jo Daviess, Mercer and 5 more | 6 hr |
| Aug 26, 11:53 PM CDT | Mesoscale Discussion | SPC | Bureau, Cook, DeKalb, DuPage, Grundy, Kane and 8 more | 97 min |
| Aug 27, 1:49 AM CDT | Mesoscale Discussion | SPC | Henderson, Henry, Mercer, Ogle, Rock Island, Whiteside and 1 more | 56 min |
| Aug 27, 4:36 AM CDT | Mesoscale Discussion | SPC | Cook, DeWitt, Ford, Fulton, Grundy, Hancock and 11 more | 84 min |
| Aug 27, 6:33 AM CDT | Mesoscale Discussion | SPC | Champaign, DeWitt, Ford, Iroquois, McLean, Mason and 4 more | 27 min |
| Aug 27, 9:24 AM CDT | Mesoscale Discussion | SPC | Calhoun, Greene, Jersey, Macoupin, Madison, Morgan and 2 more | 96 min |
| Aug 27, 9:40 AM CDT | Severe Thunderstorm Watch | SPC | Brown, Calhoun, Cass, Greene, Jersey, Macoupin and 7 more | 5 hr |
| Aug 27, 1:07 PM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Calhoun, Greene, Jersey and 6 more | 113 min |
| Aug 27, 2:45 PM CDT | Severe Thunderstorm Watch | SPC | Calhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more | 6 hr |
| Aug 27, 3:49 PM CDT | Mesoscale Discussion | SPC | Calhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more | 86 min |
| Aug 27, 4:10 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Fulton, Hancock, Henderson and 14 more | 2 hr |
| Aug 27, 12:10 PM CDT | Mesoscale Discussion | SPC | Adams, Allen, Blackford, Carroll, Cass, DeKalb and 8 more | 3 hr |
| Aug 27, 1:39 AM CDT | Mesoscale Discussion | SPC | Antrim, Arenac, Benzie, Cheboygan, Clare, Crawford and 15 more | 66 min |
| Aug 27, 12:39 PM CDT | Mesoscale Discussion | SPC | Barry, Bay, Calhoun, Clinton, Eaton, Genesee and 23 more | 2 hr |
| Aug 26, 7:45 PM CDT | Mesoscale Discussion | SPC | Columbia, Crawford, Grant, Green Lake, Iowa, La Crosse and 4 more | 90 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2004Severe Thunderstorm Watches in Michigan, 2004Severe Thunderstorm Watches in Indiana, 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.