Alert archive / Illinois / Severe Thunderstorm Watches in 2003

Severe Thunderstorm Watch 673

July 7, 200326 counties in Illinois; 4 counties in Indiana

The Storm Prediction Center issued this severe thunderstorm watch at Jul 7, 2003, 7:40 PM CDT for 26 counties in Illinois; 4 counties in Indiana. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jul 7, 2003, 7:40 PM CDT (00:40 UTC)
Expired: Jul 7, 2003, 11:00 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 30 counties

Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, McHenry County, IL, Ogle County, IL, Putnam County, IL, Stark County, IL, Stephenson County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Jasper County, IN, Lake County, IN, Newton County, IN, Porter County, IN

The radar

The Chicago radar (KLOT), 82 km from the middle of the area, began a volume at 00:40 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

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

Issued	Product	Office	Counties	Lasted
Jul 7, 7:42 PM CDT	Severe Thunderstorm Warning	DVN	Henry	58 min
Jul 7, 8:02 PM CDT	Severe Thunderstorm Warning	DVN	Whiteside	58 min
Jul 7, 8:23 PM CDT	Severe Thunderstorm Warning	LOT	Lee	52 min
Jul 7, 8:33 PM CDT	Severe Thunderstorm Warning	DVN	Bureau	72 min
Jul 7, 8:36 PM CDT	Severe Thunderstorm Warning	ILX	Stark	54 min
Jul 7, 8:41 PM CDT	Severe Thunderstorm Warning	DVN	Henry	64 min
Jul 7, 9:02 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle	28 min
Jul 7, 9:11 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb	34 min
Jul 7, 9:35 PM CDT	Severe Thunderstorm Warning	LOT	Grundy, Kendall	25 min
Jul 7, 9:54 PM CDT	Severe Thunderstorm Warning	LOT	Will	51 min
Jul 7, 10:02 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle, Livingston	43 min
Jul 7, 10:35 PM CDT	Severe Thunderstorm Warning	LOT	Iroquois, Kankakee	40 min
Jul 7, 10:51 PM CDT	Severe Thunderstorm Warning	LOT	Newton	39 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, 0.7 hours before the alert went out and 185 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3170 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1493 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 59 m²/s²
0-3 km storm-relative helicity: 72 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.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 7, 7:16 PM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, DeKalb, DuPage, Henry and 9 more	3 hr
Jul 7, 10:18 PM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, Cook, DeKalb, DuPage and 21 more	57 min
Jul 7, 11:00 PM CDT	Severe Thunderstorm Watch	SPC	Cook, Iroquois, Kankakee, Lake, Vermilion	5 hr
Jul 7, 11:50 PM CDT	Mesoscale Discussion	SPC	Iroquois, Vermilion	85 min
Jul 8, 8:50 AM CDT	Mesoscale Discussion	SPC	Adams, Brown, Hancock, Henderson, McDonough, Mercer and 2 more	115 min
Jul 8, 9:50 AM CDT	Severe Thunderstorm Watch	SPC	Boone, Bureau, Carroll, Cook, DeKalb, DuPage and 28 more	5 hr
Jul 8, 12:25 PM CDT	Mesoscale Discussion	SPC	Clark, Clay, Crawford, Cumberland, Edwards, Effingham and 4 more	95 min
Jul 8, 12:59 PM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, Cook, DeKalb, DuPage and 28 more	91 min
Jul 8, 1:21 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calhoun, Cass, Champaign, Christian and 25 more	24 min
Jul 8, 1:45 PM CDT	Tornado Watch	SPC	Adams, Brown, Bureau, Carroll, Cass, Champaign and 48 more	5 hr
Jul 8, 3:40 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Bureau, Cass, Champaign, Christian and 41 more	95 min
Jul 8, 6:15 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Cass, Champaign, Christian, Clark and 37 more	5 hr
Jul 8, 6:46 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Cass, Champaign, DeWitt, Douglas and 14 more	3 hr
Jul 7, 9:13 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Boone, Carroll, Cass and 30 more	62 min
Jul 8, 10:05 AM CDT	Mesoscale Discussion	SPC	Adams, Allen, Benton, Blackford, Boone, Carroll and 43 more	25 min
Jul 8, 10:25 AM CDT	Severe Thunderstorm Watch	SPC	Adams, Allen, Cass, DeKalb, Elkhart, Fulton and 19 more	6 hr
Jul 8, 12:04 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Cass, DeKalb, Elkhart, Fulton and 19 more	56 min
Jul 8, 1:25 PM CDT	Severe Thunderstorm Watch	SPC	Bartholomew, Benton, Blackford, Boone, Brown, Carroll and 54 more	6 hr
Jul 8, 2:30 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Cass, DeKalb, Elkhart, Fulton and 17 more	30 min
Jul 8, 3:02 PM CDT	Mesoscale Discussion	SPC	Bartholomew, Benton, Blackford, Boone, Brown, Carroll and 54 more	88 min
Jul 8, 3:20 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Allen, DeKalb, Elkhart, Fulton, Huntington and 17 more	4 hr
Jul 8, 5:38 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Bartholomew, Benton, Blackford, Boone and 67 more	37 min
Jul 8, 6:40 PM CDT	Severe Thunderstorm Watch	SPC	Bartholomew, Benton, Blackford, Boone, Brown, Carroll and 50 more	5 hr

Nearby

Severe Thunderstorm Watches in Illinois, 2003 Severe Thunderstorm Watches in Indiana, 2003 Every 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.