Alert archive / Illinois / Severe Thunderstorm Watches in 2003
Severe Thunderstorm Watch 781
The Storm Prediction Center issued this severe thunderstorm watch at Jul 20, 2003, 11:30 PM CDT for 27 counties in Illinois; Lee County, Iowa; 8 counties in Missouri. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 20, 2003, 11:30 PM CDT (04:30 UTC)
- Expired
- Jul 21, 2003, 5:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 36 counties
Lee County, IA, Adams County, IL, Brown County, IL, Cass County, IL, Champaign County, IL, DeWitt County, IL, Douglas County, IL, Ford County, IL, Fulton County, IL, Hancock County, IL, Iroquois County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Morgan County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Clark County, MO, Knox County, MO, Lewis County, MO, Marion County, MO, Monroe County, MO, Ralls County, MO, Scotland County, MO, Shelby County, MO
The radar
The Lincoln radar (KILX), 90 km from the middle of the area, began a volume at 04:29 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
17 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 21, 12:41 AM CDT | Severe Thunderstorm Warning | LSX | Marion, Shelby | 49 min |
| Jul 21, 12:59 AM CDT | Severe Thunderstorm Warning | LSX | Adams | 46 min |
| Jul 21, 1:13 AM CDT | Severe Thunderstorm Warning | ILX | Knox, Peoria, Stark | 62 min |
| Jul 21, 1:34 AM CDT | Severe Thunderstorm Warning | ILX | Fulton | 26 min |
| Jul 21, 1:43 AM CDT | Severe Thunderstorm Warning | ILX | Tazewell, Woodford | 62 min |
| Jul 21, 1:58 AM CDT | Severe Thunderstorm Warning | ILX | McLean | 62 min |
| Jul 21, 2:14 AM CDT | Severe Thunderstorm Warning | ILX | Logan | 61 min |
| Jul 21, 2:16 AM CDT | Severe Thunderstorm Warning | LOT | Ford, Livingston | 44 min |
| Jul 21, 2:19 AM CDT | Flash Flood Warning | ILX | Peoria, Tazewell | 6 hr |
| Jul 21, 2:40 AM CDT | Severe Thunderstorm Warning | ILX | DeWitt, Macon | 65 min |
| Jul 21, 2:51 AM CDT | Severe Thunderstorm Warning | ILX | Champaign, Piatt | 54 min |
| Jul 21, 2:53 AM CDT | Severe Thunderstorm Warning | LOT | Iroquois | 37 min |
| Jul 21, 3:18 AM CDT | Flash Flood Warning | ILX | Logan | 3 hr |
| Jul 21, 3:37 AM CDT | Flash Flood Warning | ILX | DeWitt, Macon, Piatt | 6 hr |
| Jul 21, 3:50 AM CDT | Flash Flood Warning | ILX | Champaign, Vermilion | 6 hr |
| Jul 21, 3:54 AM CDT | Severe Thunderstorm Warning | ILX | Sangamon | 51 min |
| Jul 21, 4:04 AM CDT | Flash Flood Warning | ILX | Douglas | 6 hr |
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, 4.5 hours before the alert went out and 148 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
- 3041 J/kg
- Mixed-layer CIN
- -67 J/kg
- Mixed-layer LCL
- 1003 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 123 m²/s²
- 0-3 km storm-relative helicity
- 251 m²/s²
- Significant tornado parameter
- 1.5
- Supercell composite
- 9.6
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 8:08 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Fulton, Hancock, Henderson, Henry and 15 more | 2 hr |
| Jul 20, 8:30 PM CDT | Tornado Watch | SPC | Carroll, Henry, Jo Daviess, Mercer, Rock Island, Whiteside | 6 hr |
| Jul 20, 9:48 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Cook, DeKalb, DuPage, Grundy and 12 more | 117 min |
| Jul 20, 10:15 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Bureau, Cook, DeKalb, DuPage, Grundy and 12 more | 7 hr |
| Jul 20, 11:14 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Cass, Champaign, DeWitt, Ford and 29 more | 2 hr |
| Jul 21, 1:56 AM CDT | Mesoscale Discussion | SPC | Champaign, Douglas, Edgar, Ford, Iroquois, Macon and 2 more | 2 hr |
| Jul 21, 4:12 AM CDT | Mesoscale Discussion | SPC | Clay, Crawford, Edwards, Effingham, Franklin, Hamilton and 7 more | 2 hr |
| Jul 21, 3:26 PM CDT | Mesoscale Discussion | SPC | Cook | 94 min |
| Jul 20, 7:49 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Calhoun, Carroll, Cass and 17 more | 56 min |
| Jul 20, 8:50 PM CDT | Tornado Watch | SPC | Adair, Adams, Audubon, Boone, Carroll, Cass and 16 more | 5 hr |
| Jul 20, 7:05 PM CDT | Severe Thunderstorm Watch | SPC | Douglas, Howell, Oregon, Ozark, Shannon | 5 hr |
| Jul 20, 10:43 PM CDT | Mesoscale Discussion | SPC | Holt, Nodaway | 62 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2003Severe Thunderstorm Watches in Missouri, 2003Severe Thunderstorm Watches in Iowa, 2003Every severe thunderstorm watch in 2003
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.